Lymphatic capillaries-Absorb excess tissue fluid and return it to the blood stream
Lacteals (in small intestine) –absorb fats vin the form lipoproteins and transport them to the bloodstream
Lymphoid organs lymphatic vessels are sites of production and distribution of lymphocytes, which help defend the body against pathogens
Lymphatic vessels
One- way system-The movement of fluid is dependent upon skeletal muscle contraction; when the muscles contract, fluid is squeezed past a valve that closes, preventing it from flowing backwards.
a. The thoracic duct is larger than the right lymphatic duct.
1) It serves the lower extremities, abdomen, left arm, left side of the head and neck, and the left thoracic region.
2) It then delivers lymph to the left subclavian vein of the cardiovascular system.
b. …show more content…
The right lymphatic duct is smaller.
1) It serves the right arm, the right side of the head and neck, and the right thoracic region.
2) It then delivers lymph to the right subclavian vein of the cardiovascular system.
Red bone Marrow
Child has more bone marrow than adults. Why?
B cells mature
T cells developed here
Thymus
Teaches T-cells to recognize the combinations of self-molecules and foreign molecules→ make them mature
Spleen
Red pulp- consist of blood vessels and sinuses, which macrophages remove old blood cells
White pulp- consist of little lumps of lymphatic tissue
Non-specific
Mucus membranes ensnare microbes
Oil gland secretions inhibit the growth of bacteria on the skin.
The stomach has a low pH (1.2–3.0) that inhibits the growth of many bacteria.
Inflammation
Inflamed area has 4 common signs: redness heat swelling and pain mast cells- tissue dwelling cells of the immune system
Histamine chemical mediator is secreted
Increase permeability in the caps allows proteins and fluids to escape into the tissue resulting in swelling
Phagocytic