Formative Practice 10.8 (Form 4 Biology Textbook Exercise and Answer)

Question 1:
How do parasitic infections happen?

The parasitic infection that transmit the parasitic worm Brugia sp. can occur through mosquito bite.

Question 2:
Explain what would happen when the tissue fluid fails to return to the blood circulatory system.

If excess fluid is not returned to the bloodstream, body tissues become swollen due to excessive fluid accumulated in the interstitial spaces.

Question 3:
Predict what would happen to the legs of a patient who has been bedridden for a long period of time? Explain your answer.

The patient may suffer from oedema due to the accumulation of tissue fluid in interstitial spaces. This is because the return of tissue fluid to the bloodstream requires the contraction of the skeletal muscles and the muscles on the lymphatic vessel wall.

Question 4:
Lipid droplets or fat globules cannot diffuse into the villus blood capillary but must diffuse through the lacteal. Explain why.

Lipid globules are too large to diffuse into the blood capillaries but are able to diffuse through the small opening between the epithelial cells of lymphatic capillaries. This is because, unlike blood capillaries, the epithelial cells forming the walls of lymphatic capillaries are not continuous end to end. On the contrary, the ends of the lymphatic capillary cells overlap and can open like a one-way door to allow the diffusion of tissue fluid.

Leave a Comment