The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spineSpineThe human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum.Vertebral Column: Anatomy. As part of the urinary tractUrinary tractThe urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra.Urinary Tract: Anatomy, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. The kidneys also play a major role in homeostatic processes, including electrolyte concentration, blood pressure, and acid–base regulation. Grossly, they consist of an outer cortex and inner medulla. Microscopic functional units known as nephrons filter the blood through a structure called the glomerulus, and this filtrate is then modified and concentrated as it moves through a complex tubular system. The renal arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology supply the kidneys via a central opening, known as the renal hilumHilumLungs: Anatomy, on its medial side; large renal veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology empty directly into the vena cava.
PronephrosPronephrosThe primordial kidney that develops from the intermediate mesoderm in the embryos of vertebrates, and is succeeded by the mesonephros. In higher vertebrates and humans, the pronephros is a vestigial and transient structure.Development of the Urogenital System
Appears in week 4 as a cluster of a few cells that disintegrate shortly thereafter
Rudimentary and nonfunctional
MesonephrosMesonephrosOne of a pair of excretory organs (mesonephroi) which grows caudally to the first pair (pronephroi) during development. Mesonephroi are the permanent kidneys in adult amphibians and fish. In higher vertebrates, proneprhoi and most of mesonephroi degenerate with the appearance of metanephroi. The remaining ducts become wolffian ducts.Development of the Urogenital System
Begins to develop in the thoracolumbar region around week 5 as pronephrosPronephrosThe primordial kidney that develops from the intermediate mesoderm in the embryos of vertebrates, and is succeeded by the mesonephros. In higher vertebrates and humans, the pronephros is a vestigial and transient structure.Development of the Urogenital System regresses
Regresses by week 10
Consists of:
A longitudinal mesonephric duct (also known as the wolffian duct)
Begins filtering blood → filtrate travels down the mesonephric tubule → mesonephric duct → cloacaCloacaA dilated cavity extended caudally from the hindgut. In adult birds, reptiles, amphibians, and many fishes but few mammals, cloaca is a common chamber into which the digestive, urinary and reproductive tracts discharge their contents. In most mammals, cloaca gives rise to large intestine; urinary bladder; and genitalia.Development of the Abdominal Organs → allantoisAllantoisAn extra-embryonic membranous sac derived from the yolk sac of reptiles; birds; and mammals. It lies between two other extra-embryonic membranes, the amnion and the chorion. The allantois serves to store urinary wastes and mediate exchange of gas and nutrients for the developing embryo.Development of the Abdominal Organs
The mesonephric ducts persist and form part of the male reproductive system.
Graphical summary of the developing kidney: The ureteric bud grows off of the mesonephric duct and into a collection of intermediate mesodermMesodermThe middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.Gastrulation and Neurulation cells known as the metanephric blastemaMetanephric blastemaWilms Tumor. Together, this is known as the mesonephrosMesonephrosOne of a pair of excretory organs (mesonephroi) which grows caudally to the first pair (pronephroi) during development. Mesonephroi are the permanent kidneys in adult amphibians and fish. In higher vertebrates, proneprhoi and most of mesonephroi degenerate with the appearance of metanephroi. The remaining ducts become wolffian ducts.Development of the Urogenital System, which develops into the kidney. The mesonephric tubules regress. In males, the mesonephric duct persists in the ejaculatory system.
Develops starting around the 5th week of gestation
Cells in the intermediate mesodermMesodermThe middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.Gastrulation and Neurulation in the pelvic region begin to differentiate into a structure called the metanephric blastemaMetanephric blastemaWilms Tumor, which:
Ultimately becomes the cells making up the nephrons
Releases growth factors that stimulate the development of an outpouching off the caudal portion of the mesonephric duct called the ureteric buds
Elongating stalk of the ureteric bud develops into the ureter.
Within the metanephric blastemaMetanephric blastemaWilms Tumor, the ureteric buds undergo a series of branchings to form the:
Renal pelvisPelvisThe pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities.Pelvis: Anatomy
Elongates, forming the tubular systemThe tubular systemThe kidneys regulate water and solute homeostasis through the processes of filtration, reabsorption, secretion, and excretion. After the filtration of blood through the glomeruli, the tubular system takes over and is responsible for adjusting the urine composition throughout the remainder of the nephron. Tubular System of the nephrons → becomes known as the metanephric tubules
The metanephric tubule fuses with the collecting tubule, creating one continuous system.
Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides: forms off the growing end of the metanephric tubule
Glomerular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology:
Develop off the common iliac arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
Become associated with Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides at the end of the metanephric tubules → begin creating “urine” (Note: True waste products are removed from the fetus via the placentaPlacentaA highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (chorionic villi) derived from trophoblasts and a maternal portion (decidua) derived from the uterine endometrium. The placenta produces an array of steroid, protein and peptide hormones (placental hormones).Placenta, Umbilical Cord, and Amniotic Cavity.)
Nephrons are formed until birth.
Nephron maturation continues after birth.
Position of the kidney and changes in vascularization
The kidneys are initially located in the pelvic region.
As the caudal portion of the body grows downward, the relative location of the kidneys “ascends” into the upper quadrants of the abdomen (failure to ascend results in a pelvic kidney).
As the kidneys ascend, the original blood supply degenerates.
New vessels (higher up) develop off the aortaAortaThe main trunk of the systemic arteries.Mediastinum and Great Vessels: Anatomy and invade the kidneys, becoming the mature renal arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
If the original vessels fail to regress, they may persist as additional renal arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology or veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology.
Ascent of the kidneys and corresponding change in vascular supply
Located along the posterior abdominal wallPosterior abdominal wallThe posterior abdominal wall is a complex musculoskeletal structure that houses the abdominal aorta, the inferior vena cava, as well as important retroperitoneal organs, like the kidneys, renal glands, pancreas, and duodenum.Posterior Abdominal Wall: Anatomy on either side of the vertebral columnVertebral columnThe human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy in the paravertebral gutter
In front of the T12–L3 transverse processes
The superior pole rests against the 11th and 12th ribsRibsA set of twelve curved bones which connect to the vertebral column posteriorly, and terminate anteriorly as costal cartilage. Together, they form a protective cage around the internal thoracic organs.Chest Wall: Anatomy.
The lower pole is directed laterally and anteriorly.
The presence of the liverLiverThe liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy on the right side forces the right kidney to be slightly lower than the left.
Anatomical relations
Table: Anatomic relations of the kidneys
Direction (in relation to the kidney)
Right
Left
Superior
Right adrenal gland
Left adrenal gland
Anterior
Upper portion: liverLiverThe liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy
Lower portion: hepatic flexure of the colonColonThe large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy
Upper portion: stomachStomachThe stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy
Mid portion: pancreasPancreasThe pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy
Lower portion: jejunumJejunumThe middle portion of the small intestine, between duodenum and ileum. It represents about 2/5 of the remaining portion of the small intestine below duodenum.Small Intestine: Anatomy
Lateral
LiverLiverThe liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy
Upper portion: SpleenSpleenThe spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen: Anatomy
Lower portion: Descending colonColonThe large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy
Posterior
Muscles:
Posterosuperior: diaphragmDiaphragmThe diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force.Diaphragm: Anatomy
Posteromedial: psoas musclePsoas muscleA powerful flexor of the thigh at the hip joint (psoas major) and a weak flexor of the trunk and lumbar spinal column (psoas minor). Psoas is derived from the greek ‘psoa.Pyelonephritis and Perinephric Abscess
Kidneys with shadings showing their anatomical relations
Image by Lecturio.
Size and shape
Bean-shaped organs
Dimensions:
Length: 10–12 cm
Width: 5–7 cm
Depth: 2–3 cm
Weight: approximately 150 g
Outer layers
Surrounding the kidneys are several layers of adipose and connective tissueConnective tissueConnective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix.Connective Tissue: Histology (from outside in):
Paranephric fat:
Located posterior to the kidney, between the renal fasciaFasciaLayers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs.Cellulitis and the back musclesBack musclesThe back is composed of several muscles of varying sizes and functions, which are grouped into intrinsic (or primary) back muscles and extrinsic (or secondary) back muscles. The extrinsic muscles comprise the superficial and intermediate muscle groups, while the intrinsic muscles comprise the deep muscles.Muscles of the Back: Anatomy
Anchors kidneys to the posterior abdominal wallPosterior abdominal wallThe posterior abdominal wall is a complex musculoskeletal structure that houses the abdominal aorta, the inferior vena cava, as well as important retroperitoneal organs, like the kidneys, renal glands, pancreas, and duodenum.Posterior Abdominal Wall: Anatomy
Provides some protection and warmth
Renal fasciaFasciaLayers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs.Cellulitis, which also encloses the adrenal gland
Layers of adipose and connective tissueConnective tissueConnective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix.Connective Tissue: Histology surrounding the kidneys (transverse section)
Image by Lecturio.
Surface features
Superior and inferior poles
Convex lateral surface
Concave medial surface, which creates a cavity called the renal sinus
The renal sinus contains:
Renal neurovasculature, including:
ArteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology and veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology
Lymphatics
Nerves
Renal pelvisPelvisThe pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities.Pelvis: Anatomy (terminal portion of the renal collecting system)
Adipose tissueAdipose tissueAdipose tissue is a specialized type of connective tissue that has both structural and highly complex metabolic functions, including energy storage, glucose homeostasis, and a multitude of endocrine capabilities. There are three types of adipose tissue, white adipose tissue, brown adipose tissue, and beige or “brite” adipose tissue, which is a transitional form.Adipose Tissue: Histology (continuous with the perinephric fat surrounding the kidney)
Projections medially form the renal columns (of Bertin).
Microscopic structures located in the cortex:
Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides
Proximal and distal tubules
Upper portions of the collecting ducts
Renal medulla:
Divided into units known as renal pyramids
6–10 renal pyramids separated by the columns of Bertin
Base of pyramid toward the cortex
The apex:
Projects toward the renal sinus
Is called a papilla
Collecting tubules drain out of the papilla into the minor calyces.
Microscopic structures located in the medulla/pyramids:
Loops of Henle
Collecting ducts
Collecting system:
Collects the newly formed urine and directs it to the ureter
Each papilla drains into a minor calyx.
2–3 minor calyces drain into a single major calyx.
2–3 major calyces converge to form the renal pelvisPelvisThe pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities.Pelvis: Anatomy, which:
Is a funnel-shaped structure that is continuous with the ureter
Nephrons are the functional units of the kidney; there are approximately 1.2 million nephrons in each kidney. The nephron is divided into 2 main parts: the renal corpuscle and the renal tubule, which has multiple defined segments.
Renal corpuscle
The renal corpuscle is where the blood plasmaPlasmaThe residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.Transfusion Products is filtered.
Glomerular (Bowman) capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides:
A ball-shaped structure surrounding a web of arterial capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology
Has an outer parietalParietalOne of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium.Skull: Anatomy layer made up of simple squamous epithelial cells
Has an inner visceral layer:
Directly surrounds the glomerular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology
Made up of specialized epithelial cells known as podocytes
Bowman space:
The space between the parietalParietalOne of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium.Skull: Anatomy and visceral layers of Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides
Collects the filtrate (urine)
Drains into the proximal convoluted tubuleProximal convoluted tubuleThe renal tubule portion that extends from the bowman capsule in the kidney cortex into the kidney medulla. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the u-shaped loop of henle.Osmotic Diuretics (PCTPCTThe renal tubule portion that extends from the bowman capsule in the kidney cortex into the kidney medulla. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the u-shaped loop of henle.Osmotic Diuretics)
Structure of the renal corpuscle
Image by Lecturio.
Blood vessels associated with the renal corpuscle:
Glomerulus (also called glomerular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology):
A web of small arterial capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology between the afferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: Histology and efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: HistologyarteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology
Filtration occurs primarily because of the high hydrostatic pressureHydrostatic pressureThe pressure due to the weight of fluid.Edema in the glomerular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology created by the large inlet (afferent arterioleAfferent arterioleGlomerular Filtration) and small outlet (efferent arterioleEfferent arterioleGlomerular Filtration).
Filtration membrane:
Constitutes the main blood filter between the glomerular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology and Bowman space
Consists of 3 layers:
Fenestrated endotheliumEndotheliumA layer of epithelium that lines the heart, blood vessels (vascular endothelium), lymph vessels (lymphatic endothelium), and the serous cavities of the body.Arteries: Histology lining the glomerular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology
Glomerular basement membraneBasement membraneA darkly stained mat-like extracellular matrix (ecm) that separates cell layers, such as epithelium from endothelium or a layer of connective tissue. The ecm layer that supports an overlying epithelium or endothelium is called basal lamina. Basement membrane (bm) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. Bm, composed mainly of type IV collagen; glycoprotein laminin; and proteoglycan, provides barriers as well as channels between interacting cell layers.Thin Basement Membrane Nephropathy (TBMN) (GBM): made up of a negatively charged proteoglycan gel (repels larger negatively charged molecules)
Podocytes (epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology):
Form the visceral layer of Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides
Multiple interdigitating footFootThe foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons.Foot: Anatomy processes wrap around the vessels, creating filtration slits between footFootThe foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons.Foot: Anatomy processes.
Slits are covered by a membrane called the slit diaphragmDiaphragmThe diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force.Diaphragm: Anatomy (a unique form of intercellular junction consisting of multiple proteinsProteinsLinear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.Energy Homeostasis).
Not permeable to large molecules in blood, such as plasmaPlasmaThe residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.Transfusion ProductsproteinsProteinsLinear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.Energy Homeostasis (e.g., albuminAlbuminSerum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood.Liver Function Tests)
Permeable to small molecules, generally < 3 nm, including:
Water
ElectrolytesElectrolytesElectrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions.Electrolytes (e.g., sodiumSodiumA member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23.Hyponatremia, potassiumPotassiumAn element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance.Hyperkalemia)
GlucoseGlucoseA primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Lactose Intolerance
Amino and fatty acidsAcidsChemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water.Acid-Base Balance
Vitamins
Can be damaged by infection and trauma
Filtration apparatus in the glomerulus
Image by Lecturio.
Renal tubule
The renal tubule is a long continuous tube that adjusts the contents of the filtrate received from the renal corpuscle. The tubules ultimately drain through the papilla into the calyces. Segments of the tubule, in order, are:
PCTPCTThe renal tubule portion that extends from the bowman capsule in the kidney cortex into the kidney medulla. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the u-shaped loop of henle.Osmotic Diuretics:
Located in the cortex
Major site of reabsorption, especially for:
ElectrolytesElectrolytesElectrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions.Electrolytes: Na+, Cl–, K+, CaCACondylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding.Condylomata Acuminata (Genital Warts)2+, Mg2+, HCO3–, PO43–
GlucoseGlucoseA primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Lactose Intolerance
Amino acidsAmino acidsOrganic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Basics of Amino Acids and peptides
Lined with simple cuboidal epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology with prominent microvilli known as a brush borderBrush borderTubular System lining the tubule lumen (↑ the surface area for reabsorption)
H&E stain: dark pink owing to high amounts of mitochondriaMitochondriaSemiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive ribosomes, transfer RNAs; amino Acyl tRNA synthetases; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs. Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes.The Cell: Organelles (↑ rates of reabsorption requires ↑ energy for active transportActive transportThe movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.The Cell: Cell Membrane)
Organic anionsAnionsNegatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.Electrolytes (e.g., bile saltsBile saltsSteroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.Cholelithiasis, urate, drugs)
Organic cationsCationsPositively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Electrolytes (e.g., creatinine, dopamineDopamineOne of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement.Receptors and Neurotransmitters of the CNS, drugs)
H&E stain: dark pink
Loop of HenleLoop of HenleThe U-shaped portion of the renal tubule in the kidney medulla, consisting of a descending limb and an ascending limb. It is situated between the proximal kidney tubule and the distal kidney tubule.Tubular System (located in the cortex and medulla), further divided into:
Thin descending and thin ascending limbs
Both made of simple squamous epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology
Involved in passive transportPassive transportThe passive movement of molecules exceeding the rate expected by simple diffusion. No energy is expended in the process. It is achieved by the introduction of passively diffusing molecules to an environment or path that is more favorable to the movement of those molecules. Examples of facilitated diffusion are passive transport of hydrophilic substances across a lipid membrane through hydrophilic pores that traverse the membrane, and the sliding of a DNA binding protein along a strand of DNA.The Cell: Cell Membrane of water or electrolytesElectrolytesElectrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions.Electrolytes, which establish the large osmotic gradient in the medulla
Cuboidal epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology
Heavily involved in active transportActive transportThe movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.The Cell: Cell Membrane of electrolytesElectrolytesElectrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions.Electrolytes
Distal convoluted tubuleDistal convoluted tubuleThe portion of renal tubule that begins from the enlarged segment of the ascending limb of the loop of henle. It reenters the kidney cortex and forms the convoluted segments of the distal tubule.Gitelman Syndrome (DCT)
Located in the cortex
Responsible for “fine tuning” the components of the urine
Lined with simple cuboidal epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology without microvilli
H&E stain: pale pink owing to fewer mitochondriaMitochondriaSemiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive ribosomes, transfer RNAs; amino Acyl tRNA synthetases; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs. Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes.The Cell: Organelles
Last part of the nephron functional unit
Collecting ductCollecting ductStraight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of bellini) which opens on the summit of the papilla.Renal Cell Carcinoma (CDCDCesarean delivery (CD) is the operative delivery of ≥ 1 infants through a surgical incision in the maternal abdomen and uterus. Cesarean deliveries may be indicated for a number of either maternal or fetal reasons, most commonly including fetal intolerance to labor, arrest of labor, a history of prior uterine surgery, fetal malpresentation, and placental abnormalities.Cesarean Delivery)
Located in the cortex and medulla
Simple cuboidal epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology
Multiple DCTs from different nephrons come together and drain into a CDCDCesarean delivery (CD) is the operative delivery of ≥ 1 infants through a surgical incision in the maternal abdomen and uterus. Cesarean deliveries may be indicated for a number of either maternal or fetal reasons, most commonly including fetal intolerance to labor, arrest of labor, a history of prior uterine surgery, fetal malpresentation, and placental abnormalities.Cesarean Delivery.
Segments of the nephron
Image by Lecturio.
Juxtaglomerular apparatus (JGA)
A specialized group of 3 cell types in close proximity to the glomerulus. The JGA plays an important role in maintaining blood pressure and fluid homeostasisHomeostasisThe processes whereby the internal environment of an organism tends to remain balanced and stable.Cell Injury and Death.
Juxtaglomerular (JG) cells:
Enlarged smooth muscle cells primarily in the afferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: Histology (and some in the efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: Histology) arteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology
Can dilate or constrict the arteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology, adjusting the pressure within the glomerulus
Secrete reninReninA highly specific (leu-leu) endopeptidase that generates angiotensin I from its precursor angiotensinogen, leading to a cascade of reactions which elevate blood pressure and increase sodium retention by the kidney in the renin-angiotensin system.Renal Sodium and Water Regulation in response to hypovolemiaHypovolemiaSepsis in Children and hypotensionHypotensionHypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
MaculaMaculaAn oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid.Eye: Anatomy densa (MD) cells:
Specialized slender, closely spaced epithelial cells in the DCT that are adjacent to the JG cells
Detect sodiumSodiumA member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23.Hyponatremia concentration of the fluid in the DCT
Signals JG cells to dilate or constrict arteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology, adjusting the GFRGFRThe volume of water filtered out of plasma through glomerular capillary walls into Bowman’s capsules per unit of time. It is considered to be equivalent to inulin clearance.Kidney Function Tests in order to maintain homeostasisHomeostasisThe processes whereby the internal environment of an organism tends to remain balanced and stable.Cell Injury and Death
Mesangial cells:
Flat and elongated cells in the cleft between the afferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: Histology and efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: HistologyarteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology
Connected to MD and JG cells by gap junctionsGap JunctionsConnections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of connexins, the family of proteins which form the junctions.The Cell: Cell Junctions
Role is still unclear, but potentially mediate communicationCommunicationThe exchange or transmission of ideas, attitudes, or beliefs between individuals or groups.Decision-making Capacity and Legal Competence between MD and JG cells
Structure of a renal corpuscle and the juxtaglomerular apparatus:
A: Renal corpuscle
B: Proximal tubuleProximal tubuleThe renal tubule portion that extends from the bowman capsule in the kidney cortex into the kidney medulla. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the u-shaped loop of henle.Tubular System
C: Distal convoluted tube
D: Juxtaglomerular apparatus
1: Basement membraneBasement membraneA darkly stained mat-like extracellular matrix (ecm) that separates cell layers, such as epithelium from endothelium or a layer of connective tissue. The ecm layer that supports an overlying epithelium or endothelium is called basal lamina. Basement membrane (bm) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. Bm, composed mainly of type IV collagen; glycoprotein laminin; and proteoglycan, provides barriers as well as channels between interacting cell layers.Thin Basement Membrane Nephropathy (TBMN)
2: Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides, parietalParietalOne of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium.Skull: Anatomy layer
3: Bowman capsuleCapsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Bacteroides, visceral layer
3a: PodocytePodocyteHighly differentiated epithelial cells of the visceral layer of bowman capsule of the kidney. They are composed of a cell body with major cell surface extensions and secondary fingerlike extensions called pedicels. They enwrap the kidney glomerulus capillaries with their cell surface extensions forming a filtration structure. The pedicels of neighboring podocytes interdigitate with each other leaving between them filtration slits that are bridged by an extracellular structure impermeable to large macromolecules called the slit diaphragm, and provide the last barrier to protein loss in the kidney.Nephritic Syndrome pedicles
3b: PodocytePodocyteHighly differentiated epithelial cells of the visceral layer of bowman capsule of the kidney. They are composed of a cell body with major cell surface extensions and secondary fingerlike extensions called pedicels. They enwrap the kidney glomerulus capillaries with their cell surface extensions forming a filtration structure. The pedicels of neighboring podocytes interdigitate with each other leaving between them filtration slits that are bridged by an extracellular structure impermeable to large macromolecules called the slit diaphragm, and provide the last barrier to protein loss in the kidney.Nephritic Syndrome
4: Bowman space (urinary space)
5a: MesangiumMesangiumThe thin membranous structure supporting the adjoining glomerular capillaries. It is composed of glomerular mesangial cells and their extracellular matrix.IgA Nephropathy—intraglomerular mesangial cells
5b: MesangiumMesangiumThe thin membranous structure supporting the adjoining glomerular capillaries. It is composed of glomerular mesangial cells and their extracellular matrix.IgA Nephropathy—extraglomerular mesangial cells
6: Juxtaglomerular cells
7: MaculaMaculaAn oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid.Eye: Anatomy densa
8: MyocytesMyocytesMature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal, cardiac, and smooth. They are derived from embryonic (precursor) muscle cells called myoblasts.Muscle Tissue: Histology (cells of smooth muscle)
9: Afferent arterioleAfferent arterioleGlomerular Filtration
10: Glomerulus capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology
11: Efferent arterioleEfferent arterioleGlomerular Filtration.
Image by Lecturio.
Types of nephrons
Nephrons are divided into cortical and juxtamedullary nephrons based on their location.
Cortical nephrons:
Located almost entirely in the cortex
Loops of Henle have a short course inside the medulla.
Juxtamedullary nephrons:
Located close to the corticomedullary junction
Loop of HenleLoop of HenleThe U-shaped portion of the renal tubule in the kidney medulla, consisting of a descending limb and an ascending limb. It is situated between the proximal kidney tubule and the distal kidney tubule.Tubular System traverses deep into the medulla.
Responsible for maintaining high osmotic gradient within medulla
Allow for stronger concentration of urine
Nephron anatomy: The left side shows a juxtamedullary nephron, while the right side shows a cortical nephronCortical nephronTubular System.
Renal and segmental arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
Each kidney is perfused by a renal arteryRenal arteryA branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters.Glomerular Filtration:
Branch off the abdominal aortaAortaThe main trunk of the systemic arteries.Mediastinum and Great Vessels: Anatomy below the superior mesenteric arterySuperior mesenteric arteryA large vessel supplying the whole length of the small intestine except the superior part of the duodenum. It also supplies the cecum and the ascending part of the colon and about half the transverse part of the colon. It arises from the anterior surface of the aorta below the celiac artery at the level of the first lumbar vertebra.Small Intestine: Anatomy (SMA)
Right renal arteryRenal arteryA branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters.Glomerular Filtration passes posterior to the vena cava.
The renal arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology divide into 5 segmental arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, which irrigate separate segments of the kidney (no anastomosis between the segments).
Renal segments:
Superior
Anterior superior
Anterior inferior
Inferior
Posterior
Segments of the kidney
Image by Lecturio.
Smaller arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology, and veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology
Segmental arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology branch into interlobar arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, which run between renal pyramids.
Interlobar arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology branch into arcuate arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, which run along the base of the renal pyramids in the renal cortex.
Arcuate arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology send off small branches called interlobular arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
Interlobular arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology branch into afferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: HistologyarteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology, which lead into Bowman capsules.
After blood leaves the glomerulus via the efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: HistologyarteriolesArteriolesThe smallest divisions of the arteries located between the muscular arteries and the capillaries.Arteries: Histology, it travels to either the peritubular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology or the vasa rectaVasa rectaGlomerular Filtration.
Peritubular capillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology: supply the cortical tubules (e.g., PCTPCTThe renal tubule portion that extends from the bowman capsule in the kidney cortex into the kidney medulla. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the u-shaped loop of henle.Osmotic Diuretics and DCT)
Capillary networks that surround the loops of Henle in the medulla
Highly permeable to solute and water
Vital in maintaining the osmotic gradient in the medulla
Blood from the peritubular and vasa rectaVasa rectaGlomerular FiltrationcapillariesCapillariesCapillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time.Capillaries: Histology drain into interlobular veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology.
Interlobular veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology → arcuate veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology → interlobar veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology → segmental veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology → renal veinRenal veinShort thick veins which return blood from the kidneys to the vena cava.Glomerular Filtration
Each kidney has a single renal veinRenal veinShort thick veins which return blood from the kidneys to the vena cava.Glomerular Filtration. These veinsVeinsVeins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology:
Run anterior to the arteriesArteriesArteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
Renal innervation includes both afferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: Histology and efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: Histology nerves through the renal nerve plexus. Innervation is via the autonomic nervous systemAutonomic nervous systemThe ANS is a component of the peripheral nervous system that uses both afferent (sensory) and efferent (effector) neurons, which control the functioning of the internal organs and involuntary processes via connections with the CNS. The ANS consists of the sympathetic and parasympathetic nervous systems. Autonomic Nervous System: Anatomy, primarily through sympathetic fibers:
Sympathetic efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: Histology nerves:
Primarily via splanchnic nerves
Only efferentEfferentNeurons which send impulses peripherally to activate muscles or secretory cells.Nervous System: Histology innervation to the nephrons and renal vasculature
Stimulation can activate the RAASRAASA blood pressure regulating system of interacting components that include renin; angiotensinogen; angiotensin converting enzyme; angiotensin i; angiotensin ii; and angiotensinase. Renin, an enzyme produced in the kidney, acts on angiotensinogen, an alpha-2 globulin produced by the liver, forming angiotensin I. Angiotensin-converting enzyme, contained in the lung, acts on angiotensin I in the plasma converting it to angiotensin II, an extremely powerful vasoconstrictor. Angiotensin II causes contraction of the arteriolar and renal vascular smooth muscle, leading to retention of salt and water in the kidney and increased arterial blood pressure. In addition, angiotensin II stimulates the release of aldosterone from the adrenal cortex, which in turn also increases salt and water retention in the kidney. Angiotensin-converting enzyme also breaks down bradykinin, a powerful vasodilator and component of the kallikrein-kinin system.Adrenal Hormones.
SensorySensoryNeurons which conduct nerve impulses to the central nervous system.Nervous System: HistologyafferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: Histology nerves: involved in blood pressure regulation
Visceral afferentAfferentNeurons which conduct nerve impulses to the central nervous system.Nervous System: Histology nerves: transmit painPainAn unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons.Pain: Types and Pathways signals to spinal cordSpinal cordThe spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy segments T11–L2
Regulate hemodynamic/blood pressure via the RAASRAASA blood pressure regulating system of interacting components that include renin; angiotensinogen; angiotensin converting enzyme; angiotensin i; angiotensin ii; and angiotensinase. Renin, an enzyme produced in the kidney, acts on angiotensinogen, an alpha-2 globulin produced by the liver, forming angiotensin I. Angiotensin-converting enzyme, contained in the lung, acts on angiotensin I in the plasma converting it to angiotensin II, an extremely powerful vasoconstrictor. Angiotensin II causes contraction of the arteriolar and renal vascular smooth muscle, leading to retention of salt and water in the kidney and increased arterial blood pressure. In addition, angiotensin II stimulates the release of aldosterone from the adrenal cortex, which in turn also increases salt and water retention in the kidney. Angiotensin-converting enzyme also breaks down bradykinin, a powerful vasodilator and component of the kallikrein-kinin system.Adrenal Hormones
Regulate acid–base status
Maintain boneBoneBone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types metabolism via selective excretion/reabsorption of calciumCalciumA basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Electrolytes and phosphatePhosphateInorganic salts of phosphoric acid.Electrolytes
Produce RBCsRBCsErythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production.Erythrocytes: Histology via secretionSecretionCoagulation Studies of erythropoietinErythropoietinGlycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation.Erythrocytes: Histology
Clinical Relevance
Duplications of the collecting system: known as a “duplex system.” Duplications of the collecting system are the most common congenitalCongenitalChorioretinitis anomaly of the urinary tractUrinary tractThe urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra.Urinary Tract: Anatomy. In these cases, a kidney will have 2 separate pelvicaliceal systems and 2 uretersUretersOne of a pair of thick-walled tubes that transports urine from the kidney pelvis to the urinary bladder.Urinary Tract: Anatomy. Ureteral insertion into the bladderBladderA musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination.Pyelonephritis and Perinephric Abscess from the duplicated system is often abnormal as well. Most affected individuals are asymptomatic, though recurrent urinary tractUrinary tractThe urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra.Urinary Tract: Anatomy infection (UTIs) or obstruction may occur.
Polycystic kidney disease (PKD): genetic condition caused by either an autosomal recessiveAutosomal recessiveAutosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited.Autosomal Recessive and Autosomal Dominant InheritancemutationMutationGenetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the PKHD1PKHD1Autosomal Recessive Polycystic Kidney Disease (ARPKD)geneGeneA category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Basic Terms of Genetics (fibrocystin) or an autosomal dominantAutosomal dominantAutosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant InheritancemutationMutationGenetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in either the PKD1 or PKD2geneGeneA category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Basic Terms of Genetics (polycystinPolycystinAutosomal dominant polycystic kidney disease (ADPKD)proteinsProteinsLinear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.Energy Homeostasis). Autosomal recessiveAutosomal recessiveAutosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited.Autosomal Recessive and Autosomal Dominant Inheritance PKD is characterized by multiple microscopic cystsCystsAny fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.Fibrocystic Change and can have serious effects in utero. Autosomal dominantAutosomal dominantAutosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance PKD is characterized by multiple larger cystsCystsAny fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.Fibrocystic Change and most commonly presents in adulthood with hematuriaHematuriaPresence of blood in the urine.Renal Cell Carcinoma and hypertensionHypertensionHypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension.
Goodpasture syndromeGoodpasture SyndromeGoodpasture syndrome, also known as anti-glomerular basement membrane (GBM) disease, is an autoimmune disease characterized by circulating antibodies directed against glomerular and alveolar basement membranes. Affected individuals present with symptoms of rapidly progressive glomerulonephritis and alveolar hemorrhage. Goodpasture Syndrome: also known as anti–glomerular basement membraneBasement membraneA darkly stained mat-like extracellular matrix (ecm) that separates cell layers, such as epithelium from endothelium or a layer of connective tissue. The ecm layer that supports an overlying epithelium or endothelium is called basal lamina. Basement membrane (bm) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. Bm, composed mainly of type IV collagen; glycoprotein laminin; and proteoglycan, provides barriers as well as channels between interacting cell layers.Thin Basement Membrane Nephropathy (TBMN) (anti-GBM) disease. Goodpasture syndromeGoodpasture SyndromeGoodpasture syndrome, also known as anti-glomerular basement membrane (GBM) disease, is an autoimmune disease characterized by circulating antibodies directed against glomerular and alveolar basement membranes. Affected individuals present with symptoms of rapidly progressive glomerulonephritis and alveolar hemorrhage. Goodpasture Syndrome is an autoimmune disease characterized by circulating antibodiesAntibodiesImmunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution.Immunoglobulins: Types and Functions directed against glomerular and alveolar basement membranes. Presentation is with signs and symptoms of rapidly progressive glomerulonephritisRapidly Progressive GlomerulonephritisRapidly progressive glomerulonephritis (RPGN) is a syndrome of severe glomerular disease with progressive loss of kidney function within weeks to months. Histologically, crescents (the proliferation of epithelial cells and the infiltration of monocytes/macrophages in the Bowman space) are found in the glomeruli and arise from immunologic injury.Rapidly Progressive Glomerulonephritis and alveolar hemorrhage. Management includes plasmapheresisPlasmapheresisProcedure whereby plasma is separated and extracted from anticoagulated whole blood and the red cells retransfused to the donor. Plasmapheresis is also employed for therapeutic use.Stevens-Johnson Syndrome and immunosuppressantsImmunosuppressantsImmunosuppressants are a class of drugs widely used in the management of autoimmune conditions and organ transplant rejection. The general effect is dampening of the immune response.Immunosuppressants. Renal transplantation is an option in individuals who develop end-stage renal failureRenal failureConditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate.Crush Syndrome.
Alport syndromeAlport SyndromeAlport syndrome, also called hereditary nephritis, is a genetic disorder caused by a mutation in the genes encoding for the alpha chains of type IV collagen, resulting in the production of abnormal type IV collagen strands. Patients present with glomerulonephritis, hypertension, edema, hematuria, and proteinuria, as well as with ocular and auditory findings. Alport Syndrome: also called hereditary nephritis. Alport syndromeAlport SyndromeAlport syndrome, also called hereditary nephritis, is a genetic disorder caused by a mutation in the genes encoding for the alpha chains of type IV collagen, resulting in the production of abnormal type IV collagen strands. Patients present with glomerulonephritis, hypertension, edema, hematuria, and proteinuria, as well as with ocular and auditory findings. Alport Syndrome is a genetic disorder caused by a mutationMutationGenetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the genesGenesA category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.DNA Types and Structure coding for the alpha chains of type IV collagenCollagenA polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth).Connective Tissue: Histology, resulting in the production of abnormal type IV collagenCollagenA polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth).Connective Tissue: Histology strands. Presentation is with glomerulonephritis, hypertensionHypertensionHypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, edemaEdemaEdema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, hematuriaHematuriaPresence of blood in the urine.Renal Cell Carcinoma, and proteinuriaProteinuriaThe presence of proteins in the urine, an indicator of kidney diseases.Nephrotic Syndrome in Children, as well as with ocular and auditory findings. A renal biopsyRenal BiopsyAntineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis will show characteristic GBM splittingSplittingDefense Mechanisms.
HydronephrosisHydronephrosisHydronephrosis is dilation of the renal collecting system as a result of the obstruction of urine outflow. Hydronephrosis can be unilateral or bilateral. Nephrolithiasis is the most common cause of hydronephrosis in young adults, while prostatic hyperplasia and neoplasm are seen in older patients. Hydronephrosis: dilation of the renal collecting system as a result of the obstruction of urine outflow. HydronephrosisHydronephrosisHydronephrosis is dilation of the renal collecting system as a result of the obstruction of urine outflow. Hydronephrosis can be unilateral or bilateral. Nephrolithiasis is the most common cause of hydronephrosis in young adults, while prostatic hyperplasia and neoplasm are seen in older patients. Hydronephrosis can be unilateral or bilateral. NephrolithiasisNephrolithiasisNephrolithiasis is the formation of a stone, or calculus, anywhere along the urinary tract caused by precipitations of solutes in the urine. The most common type of kidney stone is the calcium oxalate stone, but other types include calcium phosphate, struvite (ammonium magnesium phosphate), uric acid, and cystine stones.Nephrolithiasis is the most common cause of hydronephrosisHydronephrosisHydronephrosis is dilation of the renal collecting system as a result of the obstruction of urine outflow. Hydronephrosis can be unilateral or bilateral. Nephrolithiasis is the most common cause of hydronephrosis in young adults, while prostatic hyperplasia and neoplasm are seen in older patients. Hydronephrosis in young adults, while prostatic hyperplasiaHyperplasiaAn increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells.Cellular Adaptation and neoplasm are seen in older individuals. Presentation can be with flank painPainAn unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons.Pain: Types and Pathways, dysuriaDysuriaPainful urination. It is often associated with infections of the lower urinary tract.Urinary tract infections (UTIs), urgency, feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, palpable abdominal massMassThree-dimensional lesion that occupies a space within the breastImaging of the Breast, feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and hypertensionHypertensionHypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension. Diagnosis includes imaging with ultrasonography, CT, or IV pyelographyPyelographyHydronephrosis.
Nutcracker syndrome: occurs when the left renal veinRenal veinShort thick veins which return blood from the kidneys to the vena cava.Glomerular Filtration is compressed, affecting the venous drainage (and subsequently the arterial supply) of the left kidney, the left adrenal gland, and the left testis (in men) or the left ovary (in women). Symptoms are often vague but may include intermittent flank painPainAn unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons.Pain: Types and Pathways, hematuriaHematuriaPresence of blood in the urine.Renal Cell Carcinoma, pelvic painPainAn unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons.Pain: Types and Pathways, scrotal edemaEdemaEdema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, varicoceleVaricoceleA condition characterized by the dilated tortuous veins of the spermatic cord with a marked left-sided predominance. Adverse effect on male fertility occurs when varicocele leads to an increased scrotal (and testicular) temperature and reduced testicular volume.Varicocele, Hydrocele, and Spermatocele, or pelvic congestion syndrome.
Renal cell carcinomaRenal cell carcinomaRenal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma (RCCRCCRenal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma):tumorTumorInflammation that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinomaRenal cell carcinomaRenal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma is responsible for 80%–85% of all primary renal neoplasmsNeoplasmsNew abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Benign Bone Tumors. Most RCCs arise sporadically, but smokingSmokingWillful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand.Interstitial Lung Diseases, hypertensionHypertensionHypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, and obesityObesityObesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity are linked to the development of the disease. The condition is usually asymptomatic. The classic clinical triad of RCCRCCRenal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma is flank painPainAn unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons.Pain: Types and Pathways, hematuriaHematuriaPresence of blood in the urine.Renal Cell Carcinoma, and a palpable abdominal renal massMassThree-dimensional lesion that occupies a space within the breastImaging of the Breast, but only in about 9% of cases. Renal cell carcinomaRenal cell carcinomaRenal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma is usually diagnosed via CT scan.
Horseshoe kidneyHorseshoe KidneyCongenital Renal Abnormalities: developmental defect of kidneys in which inferior poles are fused together. As the kidney attempts to migrate superiorly during development, it is blocked by the inferior mesenteric arteryInferior mesenteric arteryThe artery supplying nearly all the left half of the transverse colon, the whole of the descending colon, the sigmoid colon, and the greater part of the rectum. It is smaller than the superior mesenteric artery and arises from the aorta above its bifurcation into the common iliac arteries.Small Intestine: Anatomy. The vascular supplies and collecting system of the kidney also tend to have various degrees of distortionDistortionDefense Mechanisms. Affected individuals are typically asymptomatic; incidental diagnosis is made on imaging. Other presentations include infection, obstruction, hydronephrosisHydronephrosisHydronephrosis is dilation of the renal collecting system as a result of the obstruction of urine outflow. Hydronephrosis can be unilateral or bilateral. Nephrolithiasis is the most common cause of hydronephrosis in young adults, while prostatic hyperplasia and neoplasm are seen in older patients. Hydronephrosis, and calculi.
Gulleroglu, K., Gulleroglu, B., Baskin, E. (2014). Nutcracker syndrome. World Journal of Nephrology 3:277–281. Retrieved September 3, 2021, from https://pubmed.ncbi.nlm.nih.gov/25374822/
Soriano, R. M., Penfold, D., Leslie, S. W. (2021). Anatomy, abdomen and pelvis, kidneys. StatPearls. Retrieved September 3, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK482385/
Saladin, K. S., Miller, L. (2004). Anatomy and physiology, 3rd ed., pp. 881–887. McGraw-Hill Education.
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