Talk:Draft 2016
From Embryology
Spleen
Spleen Anatomy
| Spleen Anatomy | |
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Spleen Function
- Immune - filters blood in much the way that the lymph nodes filter lymph.
- Lymphocytes in the spleen react to pathogens in the blood and attempt to destroy them.
- Macrophages then engulf the resulting debris, the damaged cells, and the other large particles.
- Red Blood Cell Removal - spleen (and liver) removes old and damaged erythrocytes from the circulating blood.
- Blood Reservoir - The sinuses in the spleen also act as a reservoir for blood.
- In emergencies (haemorrhage) smooth muscle in the vessel walls and in the capsule of the spleen contracts, squeezes blood out of the spleen into the general circulation.
Spleen Structure
- afferent splenic artery branches into central arterioles, which are sheathed by white pulp areas.
- white pulp areas consist of the T-cell zone (also known as the periarteriolar lymphoid sheath, PALS), arterioles and B-cell follicles.
- arterioles end in cords in the red pulp, from where the blood runs into venous sinuses that collect into the efferent splenic vein.
- larger arteries and veins run together in connective-tissue trabeculae, which are continuous with the capsule that surrounds the spleen.
- Capsule, trabeculae (dense connective tissue)
- Splenic pulp white pulp, red pulp - based on appearance and cell content.
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White Pulp
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Red Pulp
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Reticular Fibers (type III collagen) act as supporting meshwork.
