The spleen is the largest lymphatic organ in the body. Surrounded by a connective tissue capsule, which extends inward to divide the organ into lobules, the spleen consists of two types of tissue called white pulp and red pulp.
What is the spleen capsule made of?
The spleen is surrounded by a capsule composed of dense fibrous tissue, elastic fibers, and smooth muscle. The outermost layer of the splenic capsule is composed of mesothelial cells, which may not be evident on histologic section.
What does the spleen contain?
The spleen contains two main regions of tissue called white pulp and red pulp. Red pulp: Contains venous sinuses (cavities filled with blood), and splenic cords (connective tissues containing red blood cells and white blood cells). White pulp: Mostly consists of immune cells (T cells and B cells).
What are the 3 zones of spleen?
In mammals the white pulp of the spleen is composed of three compartments, the periarteriolar lymphatic sheath (PALS), the follicles, and the marginal zone (MZ). The PALS is a T cell compartment directly surrounding the so-called central arterioles.
What are the macrophages in the spleen called?
The spleen is the 2nd largest unit of the mononuclear phagocyte system. The monocyte is formed in the bone marrow and transported by the blood; it migrates into the tissues, where it transforms into a histiocyte or a macrophage. … Cell types and locations.
| Cell Name | Location |
|---|---|
| Peritoneal macrophages | Peritoneal cavity |
What is red pulp?
Red pulp is a loose spongy tissue with chords of reticular cells located between venous sinuses that contains lymphocytes, macrophages, granulocytes, and plasma cells.
What is the function of the capsule of the spleen?
The capsule of the spleen consists of dense irregular fibroelastic tissue. The connective tissue of the capsule contains contractile cells called myofibroblasts. By producing weak contraction of the capsule, these cells help to discharge the blood stored within the spleen into the circulation.
What is white and red pulp?
White pulp is material which is part of the immune system (lymphatic tissue) mainly made up of white blood cells. Red pulp is made up of blood-filled cavities (venous sinuses) and splenic cords. Splenic cords are special tissues which contain different types of red and white blood cells.
What is red pulp of spleen?
The red pulp of the spleen is composed of connective tissue known also as the cords of Billroth and many splenic sinusoids that are engorged with blood, giving it a red color. Its primary function is to filter the blood of antigens, microorganisms, and defective or worn-out red blood cells.
Where are antibodies produced spleen?
The sheaths surround central arteries within the spleen and contain T lymphocytes that attack foreign bodies as the blood is filtered into the spleen. The lymphatic nodules are where B-lymphocytes predominate, producing antibodies to coat pathogens and flag them up for removal by scavenger cells.
Can u live without a spleen?
The spleen is a fist-sized organ in the upper left side of your abdomen, next to your stomach and behind your left ribs. It’s an important part of your immune system, but you can survive without it. This is because the liver can take over many of the spleen’s functions.
What are the 4 functions of the spleen?
What does the spleen do?
- Stores blood.
- Filters blood by removing cellular waste and getting rid of old or damaged blood cells.
- Makes white blood cells and antibodies that help you fight infection.
- Maintains the levels of fluid in your body.
- Produces antibodies that protect you against infection.
What is lymph node capsule?
Capsule. The capsule of the lymph node is dense connective tissue stroma and collagenous fibers. The capsule sends trabeculae inside the lymph node, which pass inward, radiating towards the center.
Does all blood flow through spleen?
Healthy blood cells simply pass through the spleen and continue to circulate throughout your bloodstream. Blood cells that can’t pass the test will be broken down in your spleen by macrophages. Macrophages are large white blood cells that specialize in destroying these unhealthy red blood cells.
What is pals in spleen?
Periarteriolar lymphoid sheaths (or periarterial lymphatic sheaths, or PALS) are a portion of the white pulp of the spleen. They are populated largely by T cells and surround central arteries within the spleen; the PALS T-cells are presented with blood borne antigens via myeloid dendritic cells.
What is the other name of macrophages?
Thus, macrophages take different names according to their tissue location, such as osteoclasts (bone), alveolar macrophages (lung), microglial cells (brain), histiocytes (connective tissue), Kupffer cells (liver), Langerhans cells (LC) (skin), etc.
What are peritoneal macrophages?
Peritoneal macrophages are the macrophages that reside in the peritoneal cavity, a fluid-filled space located between the wall of the abdomen and the organs found in the abdomen. In the absence of peritoneal infection or inflammation, peritoneal macrophages are thought to have anti-inflammatory functions.
Where are macrophages in spleen?
Localization and phenotype of splenic MΦ subsets. MZMΦs (in green) are found in the marginal zone (MZ) outer layer – they are also in direct contact with blood-borne particles. These cells express in their surface the molecules MARCO and SIGNR1 and other receptors that help in the uptake of blood-borne pathogens.
What is white pulp?
White pulp is the name given to the splenic regions containing the splenic arterioles with their periarteriolar lymphoid tissue sheaths, the follicles, and the marginal zone.
What is sinuses in spleen?
Any of the vascular collecting channels that lead into the internal veins of the spleen. The microcirculation in the spleen is quite leaky.
What is the function of the white pulp?
Because of this, the white pulp of the spleen has a very important role in the normal immune response to infection. Antigen presenting cells may enter the white pulp, resulting in activation of the T-lymphocytes stored there.
Which of the following is an encapsulated lymphatic organ?
A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue.
Which organ is known as Graveyard of RBC?
Spleen is known as the graveyard of RBCs in light of the fact that after fulfillment of life expectancy, RBCs are pulverized in the spleen where they are ingested by free macrophages. About 2.5 million of RBCs are destroyed in one second. Thus, the option (D) is the correct answer.
Why is the spleen so vulnerable to serious injury?
Sometimes a collection of blood (hematoma) forms under the covering of the spleen or deep within it. ) makes the spleen more susceptible to injury. When the spleen is injured, blood may be released into the abdomen. The amount of bleeding depends on the size of the injury.
What is macrophage?
Listen to pronunciation. (MA-kroh-fayj) A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.
What causes splenomegaly?
Causes
- Viral infections, such as mononucleosis.
- Bacterial infections, such as syphilis or an infection of your heart’s inner lining (endocarditis)
- Parasitic infections, such as malaria.
- Cirrhosis and other diseases affecting the liver.
What is splenic pulp?
Medical Definition of splenic pulp : the characteristic tissue of the spleen.
Why is it called white pulp?
White pulp is a histological designation for regions of the spleen (named because it appears whiter than the surrounding red pulp on gross section), that encompasses approximately 25% of splenic tissue. White pulp consists entirely of lymphoid tissue.
What is the role of the red and white pulp in the spleen?
Both white and red pulp contains lymphocytes and immune cells called macrophages. These cells dispose of antigens, dead cells, and debris by engulfing and digesting them. While the spleen functions chiefly to filter blood, it also stores red blood cells and platelets.
Does the spleen have macrophages?
We have characterized the major resident macrophages in the human spleen, the red pulp macrophages, as a unique population with major differences in expression for surface receptors such as the FcγRs, as opposed to monocytes and monocyte-derived macrophages.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.