Encapsulated Lymph Tissue

Question 1

Spleen

Answer 1

LSQ
Macrophages- destroy old RBC's
Reservoir of 1/3 platelets
Hematopoiesis location
Capsule- collagen, elastic fibers, smooth muscle
Trabeculae- extend and make incomplete compartments
No cortex/medula
White pulp- lymph tissue
Red pulp- RBC's

Question 2

White Pulp in spleen

Answer 2

Germinal center
Corona
Central artery
Periarteriolar lymphoid sheaths
Marginal zone- where red and white pulp interact

Question 3

Red pulp in spleen

Answer 3

Splenic cord formed by reticular cells
splenic sinusoid
Pennicillar arteries
macrophage sheathed capillaries
circulating blood cells

Question 4

Splenic Artery

Answer 4

Splenic artery-trabecular arteries- Central artery- PALS- Penicillar arteriole- Splenic sinusoids or open circulation

Question 5

Lymph Nodes

Answer 5

smallest, most numerous encapsulated lymphoid organs
Removes antigens and cellular debris, Produce lymphocytes, add antibodies
Surrounded by connective tissue capsule
Trabeculae extend into parenchyma between cortical nodules
Outer cortex- lymphatic nodule (germinal center, mantle), Subscapular sinus
Inner Cortex- T cell rich- lymphatic nodules
Inner medulla
Hilum
Medullary cords- primarily comprised of macrophages and plasma cells
Medullary sinuses- spaces lined by endothelial cells surrounded by reticular cells and macrophages

Question 6

Thymus

Answer 6

Produces T-lymphocytes
Dereases in size with age
Largely replaced by fat and connective tissue
Continues to produce T-lymphocytes in adults\
Two lobes
Connective tissue capsule
Thymic capsule, capsular vein, cortex, medulla,
Hassall’s Corpuscles- in medulla, closely packed epithelial cells, release a factor that stimulates dendritic cells to complete maturation to T-cells
See image on thymus-blood barrier (epithelial reticular cells bound to capillaries)