The primary functions of the GI tract include the digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption of food and the absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption of nutrients. Multiple organs in the GI system secrete various substances into the lumen to assist in digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption and/or the regulation of GI function. The majority of digestive secretions come from the salivary glands Salivary glands The salivary glands are exocrine glands positioned in and around the oral cavity. These glands are responsible for secreting saliva into the mouth, which aids in digestion. There are 3 major paired salivary glands: the sublingual, submandibular, and parotid glands. Salivary Glands: Anatomy, stomach Stomach The 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, pancreas Pancreas The 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, and gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy, although the intestines secrete fluids and mucus too, which are critical in protecting their inner walls.
Last updated: 24 Dec, 2021
Digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption is divided into 3 phases, namely cephalic, gastric, and intestinal.
Neural regulation of gastric secretions:
The enteric
nervous system
Nervous system
The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system.
Nervous System: Anatomy, Structure, and Classification (ENS) reflex (also known as the short reflex) and the vaso-vagal reflex (also known as the long reflex) are shown.
GRP:
gastrin-releasing peptide
gastrin-releasing peptide
Neuropeptide and gut hormone that helps regulate gastric acid secretion and motor function. Once released from nerves in the antrum of the stomach, the neuropeptide stimulates release of gastrin from the gastrin-secreting cells.
Gastrointestinal Neural and Hormonal Signaling
Phases of digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption with their functional components
Image by Lecturio.There are 3 primary salivary glands Salivary glands The salivary glands are exocrine glands positioned in and around the oral cavity. These glands are responsible for secreting saliva into the mouth, which aids in digestion. There are 3 major paired salivary glands: the sublingual, submandibular, and parotid glands. Salivary Glands: Anatomy (all with a tubuloacinar structure), which together produce a combination of serous and mucous secretions.
Location of the 3 primary
salivary glands
Salivary glands
The salivary glands are exocrine glands positioned in and around the oral cavity. These glands are responsible for secreting saliva into the mouth, which aids in digestion. There are 3 major paired salivary glands: the sublingual, submandibular, and parotid glands.
Salivary Glands: Anatomy:
Parotid, submandibular, and sublingual glands
Saliva Saliva The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin. Salivary Glands: Anatomy consists of:
Overview:
Diagram detailing the ionic secretion Secretion Coagulation Studies by acinar cells and their movement across ductal cells
Image by Lecturio.Acinar cells:
Acinar cells secrete a filtrate containing Na+, K+, Cl–, HCO3–, water, and other substances.
Diagram showing ion
secretion
Secretion
Coagulation Studies by acinar cells:
In the acinar cells, Na+, K+, Cl–, and HCO3– are filtered or secreted into the salivary fluid (note: Na+ and Cl– are later reabsorbed by ductal cells).
Ductal cells:
Ductal cells modify the filtrate as it moves through the ducts, ultimately reabsorbing Na+ and Cl– and secreting more K+ and HCO3–.
Diagram showing ion transport by ductal cells:
The Na+/H+ cotransporter reabsorbs Na+ and H+ from the salivary fluid. The Na+ is then pumped across the basolateral membrane by Na+/K+ ATPase, and K+ is brought into the cell. Next, H+ is recycled back into the lumen along with K+ via an H+/K+ cotransporter. The H+ is then used to reabsorb more Na+, whereas K+ remains in the
saliva
Saliva
The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin.
Salivary Glands: Anatomy and is excreted.
Chloride
Chloride
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
Electrolytes is reabsorbed, whereas HCO3– is excreted via the Cl–/HCO3– exchanger on the apical membrane.
Salivary
secretion
Secretion
Coagulation Studies of ions and their
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products levels:
If the concentration of the ion in
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products is higher than that in
saliva
Saliva
The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin.
Salivary Glands: Anatomy, the ion is reabsorbed. If the concentration of the ion in
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products is lower than that in
saliva
Saliva
The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin.
Salivary Glands: Anatomy, the ion is secreted. The faster the
saliva
Saliva
The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin.
Salivary Glands: Anatomy
flow
Flow
Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls.
Vascular Resistance, Flow, and Mean Arterial Pressure, the less time there is for the
secretion
Secretion
Coagulation Studies or reabsorption of ions, thereby affecting their salivary concentrations. Higher concentrations of Na+ and Cl– are present in the
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products than in the
saliva
Saliva
The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin.
Salivary Glands: Anatomy and are thus are reabsorbed, whereas K+ and HCO3– are present at lower concentrations in the
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products than in
saliva
Saliva
The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin.
Salivary Glands: Anatomy, and are thus secreted.
Xerostomia Xerostomia Decreased salivary flow. Sjögren’s Syndrome, or dry mouth, is the clinical term used to identify impaired salivary secretion Secretion Coagulation Studies, which occurs commonly as part of Sjögren syndrome Sjögren Syndrome Rheumatoid Arthritis, as an adverse effect of some medications (such as antidepressants, antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs, or anticholinergics Anticholinergics Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs), and in individuals undergoing radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma therapy for head and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess cancers.
Gastric oxyntic glands are found below (and emptying into) the gastric pits. The glands contain numerous cell types, including:
Layers of the
stomach
Stomach
The 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 wall:
In the
epithelium
Epithelium
The 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, gastric pits lead to
gastric glands
Gastric glands
Stomach: Anatomy that secrete a variety of substances to aid in
digestion
Digestion
Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body.
Digestion and Absorption.
Structure of a gastric gland with its different cell types
Image by Lecturio.Ion movement in
parietal
Parietal
One 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 cells:
Carbonic acid dissociates into H+ and HCO3–. The H+ is exchanged for K+ in the apical membrane by H+/K+ ATPase. An HCO3– is exchanged for Cl– in the basolateral membrane; Cl– is then moved into the lumen.
Gastric secretions are heavily influenced by parasympathetic signaling via the vagus nerve Vagus nerve The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx). Pharynx: Anatomy (cranial nerve X), which releases ACh ACh A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. Receptors and Neurotransmitters of the CNS that induces acid production by several pathways.
Diagram showing stimulation and inhibition pathways for acid
secretion
Secretion
Coagulation Studies in a
parietal cell
Parietal cell
Rounded or pyramidal cells of the gastric glands. They secrete hydrochloric acid and produce gastric intrinsic factor, a glycoprotein that binds vitamin B12.
Gastroesophageal Reflux Disease (GERD):
Gastrin and
acetylcholine
Acetylcholine
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS activate Gq, a G protein, which cleaves phosphatidylinositol-4,5-bisphosphate (PIP2) into
inositol trisphosphate
Inositol trisphosphate
Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4, 5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1, 4, 5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell’s endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.
Second Messengers (IP3) and
diacylglycerol
Diacylglycerol
Second Messengers (
DAG
DAG
Second Messengers).
Inositol trisphosphate
Inositol trisphosphate
Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4, 5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1, 4, 5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell’s endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.
Second Messengers causes
calcium
Calcium
A 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 (
Ca
CA
Condylomata 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)
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology from the ER, while
DAG
DAG
Second Messengers activates
protein kinase
Protein kinase
A family of enzymes that catalyze the conversion of ATP and a protein to adp and a phosphoprotein.
Interferons C (PKC) via
phosphorylation
Phosphorylation
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Post-translational Protein Processing. Both
Ca
CA
Condylomata 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 and PKC stimulate the H+/K+
pump
Pump
ACES and RUSH: Resuscitation Ultrasound Protocols to secrete acid. Histamine activates Gs, which activates adenylate cyclase (AC), resulting in an increase of intracellular
cAMP
cAMP
An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth.
Phosphodiesterase Inhibitors. Next,
cAMP
cAMP
An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth.
Phosphodiesterase Inhibitors activates
protein kinase
Protein kinase
A family of enzymes that catalyze the conversion of ATP and a protein to adp and a phosphoprotein.
Interferons A (PKA), which stimulates the H+/K+
pump
Pump
ACES and RUSH: Resuscitation Ultrasound Protocols to secrete acid. Somatostatin and
prostaglandins
Prostaglandins
A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.
Eicosanoids inhibit acid production by inducing Gi, which inhibits AC.
CCK: cholecystokinin
PLC:
phospholipase C
Phospholipase C
A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of glycerophospholipids. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of phosphatidylcholine, it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of phosphatidylinositols.
Pseudomonas
Ach
ACh
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS:
acetylcholine
Acetylcholine
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS
Diagram detailing the direct and indirect pathways of acid-release stimulation by
acetylcholine
Acetylcholine
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS (
ACh
ACh
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS):
The
direct pathway
Direct Pathway
Huntington Disease involves stimulation of the muscarinic (M3)
receptors
Receptors
Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell.
Receptors on
parietal
Parietal
One 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 cells. The indirect pathways involve the stimulation of enterochromaffin-like (ECL) cells, inducing the
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology of histamine, and the stimulation of G cells inducing them to secrete gastrin. Both histamine and gastrin then stimulate
parietal
Parietal
One 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 cells to secrete acid.
ENS: enteric
nervous system
Nervous system
The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system.
Nervous System: Anatomy, Structure, and Classification
CCK: cholecystokinin
Somatostatin and prostaglandins Prostaglandins A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes. Eicosanoids:
There are 2 types of pancreatic tissues:
A drawing of the pancreas Pancreas The 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 identifying its 2 major tissue components: the endocrine pancreas Endocrine pancreas Pancreas: Anatomy (islets of Langerhans or pancreatic islets) and exocrine pancreas Exocrine pancreas The major component (about 80%) of the pancreas composed of acinar functional units of tubular and spherical cells. The acinar cells synthesize and secrete several digestive enzymes such as trypsinogen; lipase; amylase; and ribonuclease. Secretion from the exocrine pancreas drains into the pancreatic ductal system and empties into the duodenum. Pancreas: Anatomy (exocrine cells or pancreatic acini)
Image by Lecturio.The exocrine pancreas Exocrine pancreas The major component (about 80%) of the pancreas composed of acinar functional units of tubular and spherical cells. The acinar cells synthesize and secrete several digestive enzymes such as trypsinogen; lipase; amylase; and ribonuclease. Secretion from the exocrine pancreas drains into the pancreatic ductal system and empties into the duodenum. Pancreas: Anatomy secretes a mixture known as pancreatic juice Pancreatic Juice The fluid containing digestive enzymes secreted by the pancreas in response to food in the duodenum. Pancreas: Anatomy, which contains water, enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes, zymogens (inactive proteins Proteins Linear 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), HCO3–, and electrolytes Electrolytes Electrolytes 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:
Pancreatic
secretion
Secretion
Coagulation Studies of ions and their
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products levels:
Note that as the
flow rate
Flow rate
maximum flow the ventilator will deliver a set tidal volume in liters per minute
Invasive Mechanical Ventilation (x-axis) increases, HCO3– concentration in the pancreatic
secretion
Secretion
Coagulation Studies (y-axis) increases above
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products levels, indicating
secretion
Secretion
Coagulation Studies. The opposite happens to Cl–, where its concentration drops lower than
plasma
Plasma
The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation.
Transfusion Products levels, indicating reabsorption.
Secretion Secretion Coagulation Studies of HCO3– by pancreatic ductal cells: CO2 enters the cells, combines with water to form carbonic acid (H2CO3), and then splits into H+ and HCO3–. The H+ is moved back across the basolateral membrane into the interstitial space via an H+/Na+ exchanger, whereas HCO3– is secreted across the apical membrane into the lumen via an HCO3–/Cl– exchanger. The Cl– can be recycled back into the lumen through a Cl– channel. Next, Na+ is removed from the cell across the basolateral membrane via Na+/K+ ATPase. Some of the Na+ moves paracellularly into the lumen, bringing water with it.
Image by Lecturio.Percentage of secretions produced:
Secretion Secretion Coagulation Studies stimulation:
Diagram of an exocrine pancreatic cell and its secretion-stimulation pathways:
Note how
vasoactive intestinal peptide
Vasoactive intestinal peptide
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors.
Gastrointestinal Neural and Hormonal Signaling (
VIP
VIP
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors.
Gastrointestinal Neural and Hormonal Signaling) and secretin increase the concentration of intracellular
cAMP
cAMP
An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth.
Phosphodiesterase Inhibitors, whereas
gastrin-releasing peptide
gastrin-releasing peptide
Neuropeptide and gut hormone that helps regulate gastric acid secretion and motor function. Once released from nerves in the antrum of the stomach, the neuropeptide stimulates release of gastrin from the gastrin-secreting cells.
Gastrointestinal Neural and Hormonal Signaling (GRP),
acetylcholine
Acetylcholine
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS (
ACh
ACh
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
Receptors and Neurotransmitters of the CNS), and cholecystokinin (CCK) increase intracellular
Ca
CA
Condylomata 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+ concentrations. Both pathways result in
phosphorylation
Phosphorylation
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Post-translational Protein Processing of the structural and
regulatory proteins
Regulatory proteins
Proteins and Peptides, ultimately inducing docking and fusion of secretory granules that contain
enzymes
Enzymes
Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules.
Basics of Enzymes.
The primary function of the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy is the storage and concentration of bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy. Bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy can be concentrated in the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy by about 5%‒20% through dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration:
Mechanism of biliary concentration: Na+ is exchanged for H+ in the apical membrane and later exchanged for K+ in the basolateral membrane. Next, Cl– is exchanged for HCO3– in the apical membrane and moves to the interstitial space through its own channels Channels The Cell: Cell Membrane. The concentration gradient that is produced induces the transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System and paracellular Paracellular Renal Potassium Regulation movement of water.
Image by Lecturio.Bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy is continuously produced by the liver Liver The 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; thus, regulation is via release Release Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane. Virology from the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy.