LYMPH

    LYMPH

v  Lymph is a clear watery fluid.

v  Lymph is similar in composition to plasma,with the important exception of plasma proteins,and identical in composition to interstitial fluid.

v  Lymph transports the plasma proteins that seep out of the capillary beds back to the blood stream.

v  Lymph also carries away larger particles, e.g.bacteria and cell debris from damaged tissues,which can then be filtered out and destroyed by the lymph nodes.

v  Lymph contains lymphocytes, which circulate in the lymphatic system allowing them to patrol the different  regions of the body.

v  In the lacteals of the small intestine,fats absorbed into the lymphatics give the lymph (chyle).

             Chyle is a milky appearance.

    LYMPH VESSELS.

   LYMPH CAPILLARIES :

Ø  These originate as blind-end tubes in the interstitial spaces.

Ø  They have the same structures as blood capillaries,i.e. a single layer of endothelial cells,but their walls are more permeable to all interstitial fluid constituents ,including proteins and  cell debris.

Ø  The tiny capillaries join up to form larger lymph vessels.

Ø  Nearly all tissues have a network have a network of lymphatic vessels,the exceptions being the central nervous system ,the bones and the most superficial layers of the skin.

LARGE LYMPH VESSELS .

1.       The walls of lymph vessels are about the same thickness as those of small veins and have the same layers of tissue, i.e. a fibrous covering , a middle layer of smooth muscle and elastic tissue and an inner lining of epithelium .

2.       Lymph vessels have numerous cup-shaped valves to ensure that lymph flows in one way only, i.e towards the thorax.

3.       There is no pump,like the heart ,involved in the walls of the large lymph vessels has an intrinsic ability to contract rhythmically (the lymphatic pump).

4.       Any structure  that periodically compress es the lymphatic vessels can assist in the movement of lymph along the vessels,commonly including the contraction of adjacent muscles and the pulsation of large arteries.

5.       Lymph vessels become larger as they join together,eventually forming two large ducts,the thoracic duct and right lymphatic duct, which empty into the subclavian veins.

THORACIC DUCT

v  Thoracic duct begins at the cistern chili.

v  Cisterna lymph channel situated in front of the bodies of the first two lumbar vertebrae.

v  The duct is about 40 cm long and opens into the left subclavian vein in the root of the neck.

v  It drains lymph from both legs ,the pelvic and abdominal cavities,the left half of the thorax,head and neck and the right arm.

RIGHT LYMPHATIC DUCT

·         This is a dilated lymph vessel about 1 cm long.

·         It lies in the root of the neck and opens into the right subclavian vein.

It drains lymph from the right half of the thorax,head and neck and the right arm