Spleen

The 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 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 at the level of the 9th‒11th ribs just below the diaphragm Diaphragm The 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. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes Erythrocytes Erythrocytes, 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. The spleen can also activate immune responses, produce antibodies Antibodies Immunoglobulins (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, and function as a reservoir for platelet storage. There are 2 primary types of splenic tissue: red pulp, which contains dense fibrovascular networks for filtering the blood, and white pulp, which is primarily made up of lymphoid tissue surrounding the larger vessels. The spleen has a relatively weak capsule; thus, it can rupture more easily than other abdominal organs and lead to life-threatening hemorrhage.

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Development

The spleen is the largest lymphatic organ in the body.

Embryology

  • Spleen development begins during the 5th week of development.
  • Originates from the embryonic mesoderm (and not from the endoderm like the primitive gut tube)
  • Several mesenchymal buds form off the dorsal mesogastrium → fuse together to form the spleen
  • Fetal spleen has lobules that gradually regress as the organ matures → formation of the adult spleen that is divided into functional lobules
  • The fetal spleen acts solely as a hematopoietic organ until the 8th month of gestation.

Congenital variations

  • Congenital asplenia Asplenia Asplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia: congenital absence of a spleen
  • Congenital hyposplenism: congenital presence of a small, pathological spleen
  • Polysplenia: occurrence of multiple similarly sized smaller spleens (varies from 2 to 16)
  • Accessory spleens (supernumerary spleens):
    • Congenital occurrence of a primary spleen with 1 or more smaller spleens
    • Result from incomplete fusion of mesenchymal buds during development
    • Detected incidentally in 10%–30% of the population
    • When present, individuals will usually have 1–6 accessory spleens.
    • Tend to be about the size of cherries
    • Found in the splenic hilum in 75% of cases
  • Splenic lobulation: persistence of embryonic lobules in the adult 
  • Wandering spleen:
    • A rare condition in which the spleen changes positions in the abdomen
    • Caused due to malformation and excessive elasticity of the splenic ligaments that fix the spleen in the upper abdomen
  • Splenopancreatic fusion:
    • Fusion of the spleen with the tail 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
    • Usually associated with trisomy 13 Trisomy 13 Trisomy 13, or Patau syndrome, is a genetic syndrome caused by the presence of 3 copies of chromosome 13. As the 3rd most common trisomy, Patau syndrome has an incidence of 1 in 10,000 live births. Most cases of Patau syndrome are diagnosed prenatally by maternal screening and ultrasound. More than half of the pregnancies result in spontaneous abortions. Patau Syndrome (Trisomy 13)

Gross Anatomy

Location

  • LUQ of the abdomen against the left dome of the diaphragm Diaphragm The 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
  • In contact with the 9th, 10th, and 11th ribs. The long axis of the spleen corresponds to that of the left 10th rib.
  • Positioned obliquely from posterior/superior (posterior pole) to anterior/inferior (anterior pole)
  • The spleen is an intraperitoneal organ:
    • Covered by visceral peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum and Retroperitoneum
    • Suspended by mesentery folds of peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum and Retroperitoneum
    • Only the hilum of the spleen, the site through which the splenic artery and vein pass, is not covered by the peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum and Retroperitoneum.

Anatomic relationships

  • Anterior to spleen: 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
  • Lateral to spleen:
    • Diaphragm
    • Ribs and intercostal muscles
  • Medial to spleen:
    • Left kidney and adrenal gland
    • Tail 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
  • Posterior to spleen:
    • Diaphragm
    • Left lung
    • 9th–11th ribs and intercostal muscles
  • Inferior to spleen: left colic flexure

Size

Average measurements in normal healthy adults:

  • Length: approximately 10–12 cm
  • Width (at its widest portion): 7–14 cm 
  • Circumference: 11 cm
  • Weight: 150–200 grams

Ligaments

The spleen is connected to adjacent organs via several important ligaments.

  • Gastrosplenic ligament: connects the spleen to the greater curvature 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
  • Splenorenal ligament:
    • Posterior to the splenic hilum
    • Connects the spleen to the left kidney
    • Contains:
      • Splenic vessels
      • Tail 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
  • Splenocolic ligament: connects the spleen to the transverse colon Colon The 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
  • Phrenicocolic ligament:
    • A double fold of the peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum and Retroperitoneum acting as a mesentery that connects the diaphragm Diaphragm The 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 and spleen
    • Part of the greater omentum

Surface anatomy

  • Hilum:
    • The point where splenic vessels (artery, vein, and lymphatics) enter the spleen
    • Located in the middle of the medial surface
  • Impressions: indentations in the medial spleen where it is adjacent to other organs
    • Gastric impression:
      • Posterior, superior aspect of the spleen
      • In contact with 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
    • Colic impression:
      • Anterior, superior aspect of the spleen
      • In contact with the transverse colon Colon The 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
    • Renal impression:
      • Inferior aspect of the spleen
      • In contact with the left kidney
Gross anatomy of the spleen

Gross anatomy of the spleen

Image by Lecturio.

Microscopic Anatomy

The spleen consists of a capsule and inner tissue known as parenchyma. The parenchyma consists of 2 types of tissues, white pulp and red pulp.

Capsule

  • A fibroelastic capsule wraps the spleen.
  • Relatively weak:
    • Allows for an increase in size when necessary
    • Ruptures relatively easily compared with other organs
  • Numerous septa (trabeculae) extend from the capsule into the parenchyma of the spleen → divides the spleen into functional lobules

Parenchyma: white pulp

The white pulp makes up 25% of the spleen, surrounds the larger arterioles in the spleen, and contains:

  • A central arteriole
  • Periarteriolar lymphoid sheath (PALS):
    • Congregations of lymphoid tissue surrounding the central arterioles
    • Primarily composed of T cells T cells T cells, also called T lymphocytes, are important components of the adaptive immune system. Production starts from the hematopoietic stem cells in the bone marrow, from which T-cell progenitor cells arise. These cells migrate to the thymus for further maturation. T Cells
    • PALS distinguishes the spleen from other lymphatic organs.
  • Lymphoid follicles:
    • Nodules of lymphoid tissue near the central arterioles
    • Primarily composed of B cells B cells B lymphocytes, also known as B cells, are important components of the adaptive immune system. In the bone marrow, the hematopoietic stem cells go through a series of steps to become mature naive B cells. The cells migrate to secondary lymphoid organs for activation and further maturation. B Cells (antibody production)
  • Marginal zone:
    • Located at the edges of the white pulp
    • Contains antigen-presenting cells: macrophages and dendritic cells
    • Blood to be filtered leaves the vasculature in the white pulp → travels through the marginal zone to the red pulp (being “cleaned” by macrophages along the way)

Parenchyma: red pulp

The red pulp makes up 75% of the spleen and is present between the white pulp surrounding the larger vessels.

  • Consists of:
    • Bands of connective tissue Connective tissue Connective 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 known as splenic cords (cords of Billroth)
    • Reticular network of capillaries Capillaries Capillaries 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 and venous sinuses
  • White pulp transitions to red pulp as trabecular arterioles branch into the network of capillaries Capillaries Capillaries 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 and venous sinusoids.
  • Venous sinusoids:
    • Lined with reticuloendothelial macrophages
    • Splenic cords help define the structure.
    • Blood flows through the venous sinusoids → “cleaned” of foreign and defective components by macrophages
    • Very small diameter:
      • Low flow rate
      • ↑ Contact with macrophages
      • The structure is optimized for phagocytosis.

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Neurovasculature

Blood supply

  • The spleen is a highly vascular organ.
  • Arterial supply: via the splenic artery
    • Arises from the celiac trunk
    • Runs laterally along the superior aspect 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 within the splenorenal ligament
    • Branches into several smaller vessels called trabecular arteries Arteries Arteries 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 upon entering the spleen
    • Each vessel supplies a different segment of the spleen:
      • The vessels do not anastomose with each other.
      • Allows for easy surgical removal of 1 of more splenic segments
  • Venous drainage: via the splenic vein
    • Sinusoids in the red pulp drain into collecting veins Veins Veins 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 → splenic vein
    • Splenic vein:
      • Runs along the posterior aspect 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
      • Combines with the superior mesenteric vein (SMV) to form the hepatic portal vein

Patterns of blood flow

About 10% of the blood stays within the vessels, whereas approximately 90% is filtered out into the splenic tissue. Blood flows to, through, and out of the spleen as follows:

  • Aorta → celiac trunk → splenic artery → trabecular arteries Arteries Arteries 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 → splenic central arteries Arteries Arteries 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 → 
  • Blood is filtered out of the vessels →
  • Travels through lymphoid tissue in the white pulp (activates immune responses) → 
  • Travels through splenic cords/venous sinusoids in the red pulp (blood is filtered by macrophages) → 
  • Venous sinusoids → collecting veins Veins Veins 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 → splenic vein → hepatic portal vein

Lymphatics

  • The spleen acts as a large lymph node.
  • Lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes produced in the spleen exit via efferent lymph vessels → splenic lymph nodes

Innervation

Innervation of the spleen takes place via the ANS.

  • Sympathetic: celiac plexus
  • Parasympathetic: vagus nerve

Functions

The spleen is the largest secondary lymphoid organ in the body. The functions of the spleen are primarily immunologic and hematologic. Survival without a spleen is possible as it is not a vital organ.

Immune functions

  • Detection of foreign antigens in blood
  • Activation of immune responses
  • Production of antibodies Antibodies Immunoglobulins (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
  • Phagocytosis (Spleen is the most effective phagocytic compartment of the body.)

Hematologic functions

  • Cleanses the blood of old RBCs
  • Storage compartment for platelets Platelets Platelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets
  • Hematopoiesis:
    • In the fetus
    • In cases of extreme anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview in adults
  • Can compensate for hypovolemia by transferring plasma from the blood into the lymphatic system

Clinical Relevance

  • Splenomegaly Splenomegaly Splenomegaly is pathologic enlargement of the spleen that is attributable to numerous causes, including infections, hemoglobinopathies, infiltrative processes, and outflow obstruction of the portal vein. Splenomegaly: pathological enlargement of the spleen. Causes include infections, myeloproliferative disorders, hemoglobinopathies characterized by chronic extravascular hemolysis, infiltrative processes (e.g., sarcoidosis Sarcoidosis Sarcoidosis is a multisystem inflammatory disease that causes noncaseating granulomas. The exact etiology is unknown. Sarcoidosis usually affects the lungs and thoracic lymph nodes, but it can also affect almost every system in the body, including the skin, heart, and eyes, most commonly. Sarcoidosis, neoplasms), and congestive disorders (e.g., portal hypertension Portal hypertension Portal hypertension is increased pressure in the portal venous system. This increased pressure can lead to splanchnic vasodilation, collateral blood flow through portosystemic anastomoses, and increased hydrostatic pressure. There are a number of etiologies, including cirrhosis, right-sided congestive heart failure, schistosomiasis, portal vein thrombosis, hepatitis, and Budd-Chiari syndrome. Portal Hypertension, splenic vein thrombosis). The most common symptoms are abdominal discomfort or pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, increased abdominal girth, and early satiety due to compression 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. Anemia and thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia are often present.
  • Rupture of the spleen Rupture of the Spleen Splenic rupture is a medical emergency that carries a significant risk of hypovolemic shock and death. Injury to the spleen accounts for nearly half of all injuries to intra-abdominal organs. The most common reason for a rupture of the spleen is blunt abdominal trauma, specifically, motor vehicle accidents. Rupture of the Spleen: a medical emergency that carries a significant risk of hypovolemic shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock and death. The most common cause is blunt abdominal trauma, (e.g., motor vehicle accidents). For individuals with splenomegaly, however, even minimal trauma may result in splenic rupture. Affected individuals often present with LUQ abdominal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, although the pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain may be referred to the left shoulder. Management depends on hemodynamic stability and ranges from observation to splenectomy.
  • Asplenia: absence of splenic tissue or function. There is a distinction between anatomic asplenia Asplenia Asplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia, which is due to surgical removal of the spleen, and functional asplenia Asplenia Asplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia, which is due to conditions that lead to splenic atrophy, infarcts, congestion, or infiltrative disease. Individuals are at high risk of sepsis Sepsis Organ dysfunction resulting from a dysregulated systemic host response to infection separates sepsis from uncomplicated infection. The etiology is mainly bacterial and pneumonia is the most common known source. Patients commonly present with fever, tachycardia, tachypnea, hypotension, and/or altered mentation. Sepsis and Septic Shock caused by encapsulated bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology: Overview, thereby requiring adherence to a strict vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination schedule and early antibiotic treatment when an infection is suspected. Thromboembolic events are common. 
  • Hypersplenism: increased functioning of the spleen that occurs with or without organ enlargement. Sequestration of blood elements leads to congestion, whereas activation of the reticuloendothelial system leads to thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia and anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview. Hypersplenism is associated with an increased risk of splenic rupture. Individuals may present with splenomegaly, pancytopenia, and compensatory bone marrow Bone marrow Bone marrow, the primary site of hematopoiesis, is found in the cavities of cancellous bones and the medullary canals of long bones. There are 2 types: red marrow (hematopoietic with abundant blood cells) and yellow marrow (predominantly filled with adipocytes). Composition of Bone Marrow hyperplasia.
  • Splenosis: an acquired condition characterized by auto-implantation of 1 or more deposits of splenic tissue in various compartments of the body, typically occurring after abdominal trauma or surgery. Multiple ectopic splenic foci are seen, which are typically small, sessile (growing on peritoneal surfaces), and sometimes functional. Symptoms depend on the location of the implants. Affected individuals are often asymptomatic and are usually observed for further changes.
  • Splenic abscess: a rare infection associated with high mortality if not treated properly. The etiology is usually due to the spread of infection from different sites and is commonly associated with endocarditis Endocarditis Endocarditis is an inflammatory disease involving the inner lining (endometrium) of the heart, most commonly affecting the cardiac valves. Both infectious and noninfectious etiologies lead to vegetations on the valve leaflets. Patients may present with nonspecific symptoms such as fever and fatigue. Endocarditis. Symptoms include abdominal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, left pleuritic chest or shoulder pain Shoulder Pain Acute shoulder injuries are a common reason for visits to primary care physicians and EDs. Common acute shoulder injuries include acromioclavicular joint injuries, clavicle fractures, glenohumeral dislocations, proximal humerus fractures, and rotator cuff tears. Acute Shoulder Pain (due to irritation of the diaphragm Diaphragm The 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), fever Fever Fever 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 malaise. Management includes antibiotic therapy, percutaneous drainage, and surgical excision.

References

  1. Chaudhry, S. (2021). Anatomy, abdomen and pelvis Pelvis The 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, spleen. StatPearls. Retrieved September 14, 2021, from https://www.statpearls.com/articlelibrary/viewarticle/29374/ 
  2. Bajwa, S. (2021). Anatomy, abdomen and pelvis Pelvis The 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, accessory spleen. StatPearls. Retrieved September 2021 from https://www.ncbi.nlm.nih.gov/books/NBK519040/ 
  3. Bona, R. (2021). Evaluation of splenomegaly and other splenic disorders in adults. UpToDate. Retrieved September 14, 2021, from https://www.uptodate.com/contents/evaluation-of-splenomegaly-and-other-splenic-disorders-in-adults 
  4. Vancauwenberghe, T., et al. (2015). Imaging of the spleen: what the clinician needs to know. Singapore Medical Journal. 56 (3), 133–144. https://doi.org/10.11622/smedj.2015040
  5. Fremont, R.D., Rice, T.W. (2007). Splenosis: a review. South Medical Journal. 100 (6), 589–593. https://doi.org/10.1097/SMJ.0b013e318038d1f8
  6. Losanoff, J. (2020). Splenic abscess. Medscape. Retrieved September 1, 2021, from https://reference.medscape.com/article/194655-overview
  7. Vaishali, K., Wehrle, C.J., Tuma, F. (2021). Physiology, Spleen. Treasure Island (FL): StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/30725992/
  8. Varga, I., Babala, J., Kachlik, D. (2018). Anatomic variations of the spleen: current state of terminology, classification, and embryological background. Surgical and Radiologic Anatomy. 40 (1), 21–29. https://pubmed.ncbi.nlm.nih.gov/28631052/

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