The milky ?uid which is absorbed by the lymphatic vessels of the intestine. The absorbed portion consists of fats in very ?ne emulsion, like milk, so that these vessels receive the name of lacteals (L. lac, milk). This absorbed chyle mixes with the lymph and is discharged into the thoracic duct, a vessel, which passes up through the chest to open into the jugular vein on the left side of the neck, where the chyle mixes with the blood.
n. an alkaline milky liquid found within the *lacteals after a period of absorption. It consists of lymph with a suspension of minute droplets of digested fats (triglycerides), which have been absorbed from the small intestine. It is transported in the lymphatic system to the *thoracic duct. See also ascites.
Partly digested food as it issues from the stomach into the intestine. It is very acid and grey in colour, containing salts and sugars in solution, and the animal food softened into a semi-liquid mass. It is next converted into CHYLE.... chyme
Lymph is the ?uid which circulates in the lymphatic vessels of the body. It is a colourless ?uid, like blood PLASMA in composition, only rather more watery. It contains salts similar to those of blood plasma, and the same proteins, although in smaller amount: FIBRINOGEN, serum albumin (see ALBUMINS), and serum GLOBULIN. It also contains lymphocytes (white blood cells), derived from the glands. In some lymphatic vessels, the lymph contains, after meals, a great amount of FAT in the form of a ?ne milky emulsion. These are the vessels which absorb fat from the food passing down the INTESTINE, and convey it to the thoracic duct; they are called lacteals because their contents look milky (see CHYLE).
The lymph is derived, initially, from the blood, the watery constituents of which exude through the walls of the CAPILLARIES into the tissues, conveying material for the nourishment of the tissues and absorbing waste products.
The spaces in the tissues communicate with lymph capillaries, which have a structure similar to that of the capillaries of the blood-vessel system, being composed of delicate ?at cells joined edge to edge. These unite to form ?ne vessels, resembling minute veins in structure, called lymphatics, which ramify throughout the body, passing through lymphatic glands and ultimately discharging their contents into the jugular veins in the root of the neck. Other lymph vessels commence in great numbers as minute openings on the surface of the PLEURA and PERITONEUM, and act as drains for these otherwise closed cavities. When ?uid is e?used into these cavities – as in a pleural e?usion, for example – its absorption takes place through the lymphatic vessels. The course of these vessels is described under the entry on GLAND.
Lymph circulates partly by reason of the pressure at which it is driven through the walls of the blood capillaries, but mainly in consequence of incidental forces. The lymph capillaries and vessels are copiously provided with valves, which prevent any back ?ow of lymph, and every time these vessels are squeezed (as by the contraction of a muscle, or movement of a limb) the lymph is pumped along.
The term lymph is also applied to the serous ?uid contained in the vesicles which develop as the result of vaccination, and used for the purpose of vaccinating other individuals.... lymph
n. a disease, common in the tropics and subtropics, caused by the presence in the lymph vessels of the parasitic nematode worms Wuchereria bancrofti and Brugia malayi (see filaria). The worms, which are transmitted to humans by various mosquitoes (including Aëdes, Culex, Anopheles, and Mansonia), bring about inflammation and eventual blocking of lymph vessels, which causes the surrounding tissues to swell (see elephantiasis). The rupture of urinary lymphatics may lead to the presence of *chyle in the urine. Filariasis is treated with the drug *diethylcarbamazine.... filariasis
(hydroperitoneum) n. the accumulation of fluid in the peritoneal cavity, causing abdominal swelling. Causes include infections (such as tuberculosis), heart failure, *portal hypertension, *cirrhosis, and various cancers (particularly of the ovary and liver): the presence of malignant cells in the fluid, revealed by cytological examination, is usually evidence of secondary spread. Obstruction to the drainage of lymph from the abdomen results in chylous ascites (see chyle). Pancreatic ascites, due to direct communication between the pancreatic duct and the peritoneal cavity, usually following trauma or severe pancreatitis, is diagnosed by very high amylase levels in aspirated ascitic fluid. Treatment includes diuretics and ascitic drainage (paracentesis) if there is associated respiratory distress. See also oedema.... ascites