(b)(i) Able to state the meaning of lymph
Sample answer:
- a (pale) fluid within the lymphatic system
- composed primarily of interstitial fluid and lymphocytes.
(b)(ii) Able to describe how lymph is formed from blood until it is incorporated back into the
blood circulatory system.
Sample Answer :
P1: When the blood flows from arteries into capillaries, there is higher hydrostatic
pressure at the arterial end of the capillaries
P2: (This high pressure) forces some plasma to pass through the capillary walls into the
intercellular spaces (between the cells) by ultrafiltration process.
P3: Once the fluid leaves the capillary walls, it is called interstitial or tissue fluid // The
interstitial fluid fills the spaces between the cells and constantly bathes the cells
P4: 90% of the interstitial fluid diffuses back into blood capillary
P5: 10% of the interstitial fluid that has not been reabsorbed into the bloodstream goes
into the lymph capillaries.(Once inside the lymph capillaries) the fluid is known as
lymph.
P6: The lymph capillaries unite to form larger lymphatic vessels.
P7: From the lymphatic vessels, lymph eventually passes into one of two main channels,
the thoracic duct or the right lymphatic duct.
P8: The right lymphatic duct( receives lymph from the right arm, shoulder area, and the
right side of the head and neck) and empties Its lymph into the right subclavian vein.
P9: The thoracic duct (receives lymph from the left of the head, neck and chest, the
upper limb and the entire body below the ribs) and empties its lymph into the left
subclavian vein.
P10:Hence, lymph drains back into the blood circulatory system from / by subclavian
vein.
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Madam Boon @ Embun Bt. Eli
