One of the key structures of this system is the spleen. Blood from the red pulp collects in the venous sinuses which enter the trabeculae and merge into the trabecular veins figure 9. Jun 12, 2011 spleen is an important internal organ that is on average not larger than the size of a fist. Its network of trabeculae, blood vessels and lymphoid tissue provides an environment in which white blood cells lymphocytes proliferate while old damaged red blood cells erythrocytes are recycled. The red pulp is the area of spleen in between white pulp and consists of open sinuses and cellular cords. Despite its functional importance, the anatomy of the organ has not been studied as extensively as that of other organs, probably because its study presents intrinsic difficulties. Spleen cross section for histological understanding of structures. Normal structure, function, and histology of the spleen mark f. Although it may seem dispensable as it is possible to live without it, the spleen is constantly. Guided needle core biopsy is used increasingly to sample solid lesions within the spleen and, for a variety of pathologies, laparoscopic splenectomy is now the surgical method of choice. Mouse spleen typical numberspleen mouse lymph nodes red blood cells 5 x 1012 na 2. The anatomy and embryology of the spleen are well described in standard texts on those subjects 1. Megakaryocyte proliferation and atypia, often with reticulin or.
Jan 27, 2015 spleen necrosis in a male f344n rat from a chronic study higher magnification of figure 5. Pleural cavity separates spleen and diaphragm from the rib. Hi algarcy, here refers to this article below the abstract. Normal structure, function, and histology of the spleen. Nicheinduced extramedullary hematopoiesis in the spleen. The risk for any infection was highest among patients who underwent splenectomy for hematopoietic cancer, but splenectomy patients with benign blood conditions also showed significantly elevated risk for infection compared with the general population, even beyond 1 year after surgery. Spleen lien is the largest lymphoid tissue in the body and specialised, beenshaped organ for filtering blood. History of splenectomy for millennia, the spleen has been considered a fascinating and mysterious organ with more functions than any other organ. Frozen sections of spleens from different chimeras were stained with anticd19 g. This lecture will provide an overview of the lymphoid structure and histology of key cells, vessels, structures and organs lymphoid organs, including the lymph nodes, spleen and thymus, as well as extranodal lymphoid tissues including mucosal associated lymphoid tissues malt.
Histological disorganization of spleen compartments and severe. For high end tech tips, visit for latest movie trail. The red pulp makes up the majority of the spleen and is composed of a network of cell cords in series with vascular sinuses. Overview of the spleen blood disorders merck manuals. In around 20% of people, incidental findings reveal a solitary or multiple accessory spleens. The trabecular veins then converge at the hilus to form the splenic vein which drains into. Structure of spleen with diagram lymphatic tissue biology. Increased proportion of b cells in the spleen, mln, but. Spleen pathology introduction open surgery for splenectomy is performed with diminishing frequency and pathology of this organ remains a poorly understood topic. The spleen is the largest secondary lymphoid organ, is considered the draining site for compounds that are administered intravenously, and is therefore considered an important organ to evaluate for treatmentrelated lesions. Like the thymus, it only has efferent lymph vessels, which leave from. Despite its functional importance, the anatomy of the organ has. It may be confused for enlarged lymph nodes during diagnosis.
However, most of the inflowing blood passes through the marginal sinus ms and marginal zone mz, which lie between the white. The platelet count usually is 30,000mcl unless the disorder causing splenomegaly also impairs platelet production eg, in myelofibrosis with myeloid metaplasia. Spleen belongs to the lymphatic system, also note that the spleen is like a giant lymph node in the left upper quadrant of the abdomen below the left lung and diaphragm that inspects and processes the blood by filtering it past dense aggregates of lymphocytes the way that the lymph nodes treat the lymph. Hilum of spleen was not well made out, but on close examination, it was curvilinear.
Pdf normal structure, function, and histology of the spleen. So it is not supposed to be a link but a reference for what is coming next withing this article. Each compartment has its own structure, cell population, and functions. Spleen cross section for histological understanding of. Splenic tissue definition of splenic tissue by medical. The gross appearance and size of the spleen are variable, depending on the species and the degree of distension. It is structurally complex and has a number of different functions such as immunological monitoring of bloodborne antigens, storage of blood and destruction of aged or abnormal blood cells. It is a highly vascular haemopoietic organ situated in the left hypochondrium directly beneath the.
Spleen birte steiniger, university of marburg, marburg, germany the spleen is a secondary lymphoid organ present in all vertebrates. The spleen is the largest organ of your lymphatic system, a subdivision of the immune system. Histological disorganization of spleen compartments and severe visceral. The ratio of splenic weight to body weight remains fairly constant regardless of age and, in rats, is typically around 0. Surrounded by a connective tissue capsule, which extends inward to divide the organ into lobules, the spleen consists of two types of tissue. A facs staining for mature b cells using both antiigmfitc and antib220pe, in spleen top, bone marrow middle, and mln bottom. Aug 17, 2017 creating videos for youtube is something called passionate task for us.
Spleen necrosis in a male f344n rat from a chronic study higher magnification of figure 5. Organization of the splenic b cell follicle in spleen r. Enhanced histopathology of the spleen pubmed central pmc. It is similar to a lymph node in shape and structure but it is much larger. Job postings immunopedia case sharing training programs cme record keeping electronic resume parta time keeping. Attached to the embryo is a tissue mass known as the yolk sac which contains the cells destined to form both the spleen and stem cells that then go on to form different blood cells. Pdf the spleen is the largest secondary immune organ in the body and is responsible for.
These functions are carried out by the 2 main compartments of the spleen. A single spleen was studied which was enlarged and all the impressions were large and deeply concave. Organization of the splenic b cell follicle in spleen r openi. The spleen is delivered to the midline by means of blunt and sharp dissection of the areolar plane between the kidney and the pancreas.
The spleen is the largest lymphatic organ in the body. The red pulp can be expanded markedly by venous congestion, extramedullary hematopoiesis, or by involvement by leukemias. Sequestered platelets are released from the spleen at times of stress. The spleen combines the innate and adaptive immune system in a uniquely organized way. Recovery of cfus, both quantitatively and qualitatively, can proceed differently depending upon the cytotoxic agent or. If there is an excessive amount of trapping, splenectomy is sometimes recommended or the administration of na 32 po 4. Secondary iron overload occurs when iron accumulates in the body because people take too many iron supplements, receive a large number of blood transfusions, or have a disorder in which they cannot form red blood cells efficiently. As far as the spleen of fishes is concerned, the most complete and syste matic histological description is that of. Detailed anatomical and embryological descriptions have been purposely omitted from this chapter, which concentrates on the surgical relevance of spleenrelated structures and their development. Click here for the professional version click here for the professional version the spleen, a spongy, soft organ about as big as a persons fist, is located in the upper left part of the abdomen, just under the rib cage. The reticuloendothelial system is an expansive network that encompasses the haematopoietic centres, the formed elements they produce, as well as the conduits that transports them. Increased proportion of b cells in the spleen, mln, but not in the bone marrow of bafftg mice.
Mar 31, 2020 the spleen is the largest organ of your lymphatic system, a subdivision of the immune system. An acessory spleen or splenule is a small nodule formed apart from spleen. Nicheinduced extramedullary hematopoiesis in the spleen is. The spleen is a pulpy organ approximately the size of a fist, and contains the largest single aggregate of lymphoid tissue in the body. The spleen is a site of red cell elimination and destruction. B cells are found in thefollicles, marginal zone, and splenic cords. It has long been an organ of interest in popular as well as medical literature. Anatomical and histomorphological study of spleen and.
Like the lymph node, the human spleen is a highly compartimentalized organ. Therefore, thrombocytopenia caused only by splenic sequestration. Thrombocytopenia due to splenic sequestration hematology. Normal histology of the human spleen van krieken j. Spleen questions and study guide quizlet flashcards by. The relationship between the spleen colonyforming cell. The spleen is an intraperitoneal organ that lies in what quadrant and plane of the abdominal cavity.
Blood cells spleen monocytemacrophage system thymus accessory lymphoid tissues malt, tonsils some portions of the hematopoietic system are easily accessible to clinicians and provide valuable information about the health status of the patient eg blood smears and peripheral lymph node aspirates. Detailed anatomical and embryological descriptions have been purposely omitted from this chapter, which concentrates on the surgical relevance of spleen related structures and their development. The structure of the spleen enables it to remove older erythrocytes from the circulation and leads to the. The spleen is the largest mass of lymphatic tissue in the body, and is found between stomach and diaphragm. Need 3 major and 2 minor criteria for diagnosis of primary myelofibrosis pmf major criteria.
Increased proportion of b cells in the spleen, mln, but openi. Volume calculated by normal ellipsoid equation correction factor 0. Although functional asplenia is a rare event in systemic lupus erythematosus, it appears to predispose to severe septic complications. The structure of the spleen enables it to remove older. These changes combine an increase in the size and altered distribution of cell components.
In general, the marginal zones are much smaller and more variable than those of the rat and the white pulp is more prominent. This diagrammatic representation of the spleen, should help you understand where red and white pulp come from. Relative to the rat see figure 2, the mouse spleen typically has a slightly blue tint due to the increased amounts of extramedullary hematopoiesis in the red pulp. Lies just beneath the left half of the diaphragm close to 9,10 and 11 ribs and on the left side of abdomen.
Anatomical and histomorphological study of spleen and pancreas in berzem barbus pectoralis 1mahmood khaksary mahabady, 2hassan morovvati, 2ameneh arefi and 3masoud karamifar 1department of anatomy and embryology, school of veterinary medicine, shahid chamran university of ahvaz, ahvaz, iran. In inverted abdominal or systemic situs, liver is positioned on left side and spleen in right upper quadrant, often associated with spleen anomalies and variations. Creating videos for youtube is something called passionate task for us. Figure 1 spleen, red pulp extramedullary hematopoiesis, increased in a treated male b6c3f1n mouse from a chronic study. Completely intraperitoneal, except at the hilum, where splenic vessels enter exit, part of foregut anatomy of spleen. Figure 2 spleen, red pulp extramedullary hematopoiesis, increased in a. Like the lymph nodes, it also has a hilus hilium which is where the major blood vessels enter and leave. Spleen is an important internal organ that is on average not larger than the size of a fist. The spleen is located in the upper left abdominal cavity, just beneath the diaphragm, and posterior to the stomach. The spleen has been considered a mysterious organ since classical times. The superior border shows 4 notches 3 were deep and one was shallow.
The main focus of this article is the histological arrangement of the spleen. It is structurally complex and has a number of different functions such as immunological monitoring of bloodborne antigens, storage of. These include the white pulp with tcell areas and bfollicles, the nonfiltering lymphoid areas of the red pulp, the border between red and white pulp the perifollicular zone, the red pulp cord. The necrotic focus consists of necrotic cellular debris, degenerate neutrophils, and hemorrhage arrowhead and is bordered by a rim of histiocytes, lymphocytes, and fibroblasts arrow. Current diagnostic pathology 1997 4, 100105 1997 pearson professional ltd histology of the spleen. University of groningen the human spleen after trauma. The spleen can be a site of sequestration for any type of blood element hypersplenism results in early and excessive trapping of blood cell elements. The red pulp is markedly expanded by numerous hematopoietic cells arrow. Spleen questions and study guide quizlet flashcards by kendrajs.
With the spleen retracted medially, the phrenicocolic ligament is incised. Now we know this to be far from the truth, yet many individuals survive perfectly well in the absence of a functioning spleen, following surgery or as a result of diseases causing hyposplenism. Histology photo album home album list last uploads last comments most viewed top rated my favorites search. The splenic cords contain macrophages, plasma cells, lymphocytes and other mature blood cells e. Sh lecture lymphatic structure and organs embryology. There were no notches on the inferior border and intermediate border. It shows how the artery has a lymphoid sheath surrounding the artery, as it enters the spleen, with aggregations of secondary lymphoid tissue. For many years after its existence became known, it appeared to have no function. The spleen is the largest secondary immune organ in the body and is responsible for initiating immune reactions to bloodborne antigens and for filtering the blood of foreign material and old or damaged red blood cells. Sometimes, after a therapeutic splenectomy, it may show continued symptoms.
Usually, it is found near the hilum of the main spleen, but also further in the abdomen, or even in the pelvic or scrotal area. The timing at which the spleen first appears varies from species to species, however in humans it is present from the fifth week of gestation or embryo development. In this article we will discuss about the structure of spleen with the help of suitable diagram. Spleen scan abnormalities fully reversed at 1 year.
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