Exercise 35: Lymphatic System

Why is the lymphatic system one way?

Lymph only has 1 destination - the bloodstream (where the subclavian and jugular veins meet)

How do lymphatic vessels resemble veins?

They both have 3 tunics and valves, but don’t have much smooth muscle compared to arteries

How are lymphatic capillaries different from blood capillaries?

lymph capillaries are branched with open ends, as opposed to blood capillaries that are branched but the ends reconnect

What is the function of lymphatic vessels?

pick up leaked fluid from cardiovascular system

What is lymph?

Fluid containing WBC that cycles through the body to defend from pathogens

What factors are involved in the flow of lymphatic fluid?

skeletal muscles and thoracic movement from breathing

Thoracic duct

Duct that drains most of the body (everything but left arm, chest, and head)

Capsule

fibrous surrounding of a lymph node

Trabeculae

connective tissue septa that divide the lymph node into smaller compartments

Lymphoid follicle

cluster of T and B cells surrounding germinal center

Subcapsular Sinus

space between lymphoid follicles and the cortex/trabeculae

Hilium

Area of the lymph node with a few efferent vessels

What regions of the body have clusters of lymph nodes?

cervical, axillary, inguinal

White pulp

lymphocytes suspended in reticular fibers, clustered around central arteries

Red pulp

sinusoids and splenic cords - reticular tissue and macrophages that remove worn out red blood cells, debris, bacteria, viruses, and toxins

Tonsillar crypt

folds that trap bacteria to be destroyed in the tonsils

Tonsils

trap bacteria and foreign material that work their way into lymphoid tissue to be destroyed

Thymus

location of maturation of T cells
Red bone marrow

Spleen

lymphoid organ that clears defective cells from blood and fights infection

Peyer’s patches

aggregated lymphoid nodules in small intestine

Appendix

lymphoid organ on bottom right large intestine, produces bacteria for the digestive system