Flashcards in TBL17 - Spleen Deck (9):
Where does the retroperitoneal splenic artery course?
The retroperitoneal splenic artery courses within the splenorenal ligament to reach the hilum of the spleen i.e., the ligament serves as a mesentery
Where do the short gastric arteries branch from and where? Where do the short gastric arteries course and what do they supply?
1) The short gastric arteries branch from the splenic artery before it enters the splenorenal ligament
2) The short gastric arteries course within the gastrosplenic ligament to supply the fundus of the intraperitoneal stomach
What do the splenic capsule and inward projecting trabeculae encompass?
The dense connective tissue splenic capsule and the inward projecting trabeculae encompass a dense meshwork of reticular fibers designated the splenic pulp
What is white pulp? What is red pulp? What is discharged into the red pulp?
1) Pulp contains scattered lymphoid nodules, which are collectively called white pulp
2) The vast intervening meshwork of reticular fibers is filled mainly with erythrocytes; thus, it is called red pulp
3) Open-ended capillaries discharge RBCs and the other formed elements of blood directly into the red pulp
Where do branches of the splenic artery course to get to the red pulp? Where do these branches terminate? What interweaves throughout the red pulp for drainage?
1) Branches of the splenic artery course in the trabeculae where small branches arise and enter the red pulp
2) The small branches terminate in the open-ended capillaries
3) A network of venous sinusoids, which drains into tributaries of the splenic vein, interweaves throughout the red pulp
What are endothelial cells of the sinusoids of the pulp separated by? What squeezes through the slits to re-enter the bloodstream from the red pulp?
1) Endothelial cells of the sinusoids are separated by slit-like spaces
2) The extravascular formed elements of the blood, except aged RBCs that lose their pliability, squeeze through the slits to re-enter the bloodstream from the red pulp
What other cell type is found in the red pulp as a permanent resident? What do these cells therefore do to aged RBCs?
1) Macrophages are permanent residents of the red pulp
2) Thus, aged RBCs are removed from the red pulp via phagocytosis
What happens to blood-borne antigens in the red pulp? What can therefore form in the white pulp?
1) Blood-borne antigens are either selectively bound by B cells or phagocytized by resident macrophages in the red pulp
2) Proliferation of antigen-bound B cells forms the lymphoid nodules of the white pulp