lymph . The lymphatic system consists of a complex network of thin walled ducts (lymphatic vessels), filtering bodies (lymph nodes) and a large number of lymphocytic cell concentrations in various lymphoid organs. The lymphatic vessels have smooth walls that run parallel to the blood vessels, in the skin, along the respiratory and digestive tracts. These vessels serve as return ducts for the fluids that are continually diffusing out of the blood capillaries into the body tissues.
The end of a vessel is shown in Figure . . 7LVVXHIOXLG GUDLQDJH 7LVVXHFHOO /\PSK /\PSK YHVVHO 9DOYHLQO\PSK YHVVHOZDOO Figure . Drainage of Tissue fluid into a Lymph Vessel Lymph fluid must pass through the lymph nodes before it is returned to the blood.
The lymph nodes that filter the fluid from the lymphatic vessels of the skin are highly concentrated in the neck, inguinal, axillaries, respiratory and digestive tracts. The lymph fluid flowing out of the lymph nodes flow into large collecting duct which finally drains into larger veins that runs beneath the collar bone, the subclavian vein and is emptied into the blood stream. The narrow passages in the lymph nodes are the sinusoids that are lined with macrophages. The lymph nodes successfully prevent the invading microorganisms from reaching the blood stream.
Cells found in the lymphatics are the lymphocytes . Lymphocytes collected in the lymphatic fluid are carried via the arterial blood and are recycled back to the lymph. Fats are absorbed through lymph in the lacteals present in the villi of the intestinal wall. .
Why protein molecules of larger size can pass through the lymph vessel? . We have seen that capillary walls are not permeable to plasma proteins. Suggest where the protein comes from.
. The disease kwashiorkor is caused by a diet which is very low in pro- tein. The concentration of proteins in blood becomes much lower than usual. One of the symptoms of kwashiorkor is edema.
Give reasons. . Blood vessels – Arteries,