Lymphatic capillaries, collecting vessels, lymphatic trunks, collecting ducts, and subclavian veins

makeup of lymph nodes

numerous B and T lymphocytes and macrophages that remove bacteria, cellular debris and cancer cells from the lymph fluid

tunica externa

outer layer of a blood vessel or collecting vessel which connects it to surrounding tissues

when fluid builds up in the interstitial spaces

cells are pulled apart and interstitial fluid flows into the lumen of the lymphatic capillary

reticular cells

a type of macrophage

collecting vessels

are formed by merging lymphatic capillaries; contain numerous valves that assist lymph transport

why the pulsing of blood in the arteries assists the flow of lymph

because lymphatic vessels often travel alongside veins and arteries

structural similarity between collecting vessels and venules

both are composed of: tunica interna, tunica media, tunica externa

tunica interna

contain valves to assist one way flow

composition of lymphatic capillaries

endothelial cells that overlap each other like shingles; unlike blood capillaries, they are not held together by tight junctions

lymphatic trunks

lymphatic vessels which drain lymph from large areas of the body and drain into one of the two large collecting ducts

subclavian veins

receive lymph fluid from the two collecting ducts and mixes it with blood

thoracic duct

receives lymph from all parts of the body below the diaphragm as well as the left side of the face, neck, thorax, and left upper extremity

right lymphatic duct

receives lymph from the right side of the face, neck, thorax, and right upper extremity

tunica media

rhythmic contractions of smooth muscle squeeze lymph through these vessels

origination of lymphatic capillaries

the interstitial spaces of the tissues

reticular fibers

thin collagen fibers

why numerous lymph nodes are located along lymphatic vessels

to filter and cleanse the lymph

collecting ducts

where all lymphatic trunks drain