K.C.S.E Biology Q & A - MODEL 2019PP2QN08
Explain the effect of increased physical activity on the following organ systems:
(a) heart (b) lungs (c) kidneys (d) skin.
answers
​(a) Heart
-Increased heart beat/ rate/cardiac frequency; increase blood pressure; pumping more blood to the muscles/Peripheral blood vessels; at a faster rates; supplying oxygen; Nutrients; for continued oxidation/respiration; to yield energy needed to sustain the (vigorous) contraction/relaxation of muscles during the physical activity; carbon (iv) oxide /Lactic acid/other Nitrogenous wastes/Metabolic wastes produced during the process are also eliminated/ transported to the relevant excretory organs for elimination; the wastes ,if left to accumulate Can also intoxicate/poison cells/cause muscle cramps/pain/fatigue; (b) Lungs -Panting /increased breathing rates; cause the lungs to expand/increase in volume to take in more air/oxygen; and deflate to expel more carbon (iv) oxide; more oxygen is taken in (during exercise) to sustain the process of muscle respiration/to produce the required energy (for constant muscle contraction and relaxation);
Kidneys also maintain the blood plasma pH; and osmotic balance; by elimination excess hydrogen ions(H+) that accumulate to production of Lactic acid/CO2 during the exercise; To maintain the osmotic balance kidneys conserve sodium ions (Na+); and reabsorb water (in the kidney tubules); Leading to reduction in the volume of urine produced; During exercise the kidney tend to filter out urine releasing more in the urine; (d) Skin - Due to increased muscle activity during physical exercise are sweats(more); Eliminating Nitrogenous wastes/ excess water; through the skin/sweat pores) cooling the body; After (water in) sweat evaporates the increased internal body temperature also leads to dilation of superficial blood vessels (vasodilation)/ blood flowing near the skin; leading to loss of excess heat (to the atmosphere) by radiation/ convection; the hair on the skin surface also lie Flat to allow for loss of heat( to the environment) by radiation/convection; Follow AtikaSchool.Org on our Social ChannelsThis gives you an opportunity to get our latest uodates, changes and firsthand information Don't give up, Keep Searching for more |
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