Question

Which of the following is first to receive Lymphatic duct from legs?
A) Left Subclavian vein
B) Right Subclavian vein
C) right Lymphatic duct
D) None of the above

Answer 1

Hint: In addition to the blood vascular system, all vertebrates possess a lymphatic system .It includes lymph, lymphatic vessels, lymphatic tissue, lymphatic nodules, lymph nodes, tonsils, the spleen and the thymus.

Complete answer:
>Lymph flows away from the tissues to lymph nodes and eventually to the right lymphatic or the largest lymph vessel called thoracic duct.
>Lymph is a clear, colourless fluid, similar to plasma but with much less protein .The main centre for the formation of lymph is interstitial space.
>The thoracic duct is larger and longer, and begins as a prominent sac in the abdominal cavity called the cisterna chyli.
>Lymph from the right portion of the body enters the bloodstream at the right subclavian and the rest of the body at the left subclavian vein.
>The movement of lymph is mainly due to squeezing action of the surrounding muscles, there is no pump like the heart .Lymphatic circulation is slow and uncertain, exercise increases lymph circulation.

Hence the correct answer is option ‘D’.

Note:Normally, the rate of formation of lymph in the body is equal to the rate of its return to the bloodstream .But sometimes, the formation rate of lymph exceeds the rate of its return to blood .This in turn increases the volume of fluid around the cells then creates a swelling, which is called dropsy or oedema .
>Lymphadenitis is an inflammation of the lymph nodes which causes them to become enlarged and tender
>Lymphedema is the abnormal accumulation of lymph in tissues, often the upper or lower lymphs due to disruption of lymph flow .Elephantiasis caused by roundworm Wuchereria bancrofti is a form of lymphedema
>A lymphoma is a neoplasm (tumour) of lymphatic tissue .Hodgkin's disease is a type of lymphoma.