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Biology 322
Human Anatomy
Dr. Thompson
Lymphatics
Lymphatic System Functions
1) Provide alternate pathway for extracellular fluids to
return to circulation.
2) Provide pathways for waste materials to be removed
from tissues and organs and destroyed.
3) Provide a protective lining along internal organs which
are exposed to the environment.
4) Provide places for surveillance, proliferation and
maturation of lymphocytes and other immune cells
Lymphatic System
1)
2) Lymphatic
Lymphatic tissues
Lymphatic cells
Two interrelated components:
Lymphatic vessels: Microscopic
Lymphatic vessels: Macroscopic / Gross
Concentrated
Other Lymphatic Organs and Tissues
Spleen, Thymus
Tonsils, Appendix,
Lymphatic tissue lining
Spleen
Inferior to diaphragm on left side of abdomen
Large blood supply through splenic artery
(branch of
from
Two types of tissue:
a) Red pulp produces
reservoir for
)
Spleen
Inferior to diaphragm on left side of abdomen
Large blood supply through splenic artery
(branch of celiac trunk from aorta)
Two types of tissue:
b) White pulp contains
Thymus
Superior thorac,
anterior to aorta &
posterior to sternum
Large in children,
involutes in adults
Lymphoid tissues (
) line
many hollow organs exposed to bacteria, viruses, etc
Clusters, called lymphatic nodules,
Located just deep to epithelia, easily exposed to antigens
Secrete antibodies into and across epithelia into lumen
Often located near "pits" or "crypts" where bacteria,
viruses, & other contaminants can be trapped
Lymphoid tissues (lymphocytes and macrophages) line
many hollow organs exposed to bacteria, viruses, etc
Some nodules given special names: