Question

Using one example from each of the eye and the kidney, compare how the organ ensures an optimum physiological response.

Answer 1

The function of the kidney is to filter blood and separate wastes and excess substances from the body so that they can be excreted. The concentration of the urine is maintained by its own auto regulatory methods. When the rate of filtration is low whch can be due to low blood pressure, kidneys will increase the blood pressure by secreting hormones such as Renin. This hormone ultimately results in the production of aldosterone which increases the blood pressure by absorbing more Na ions. When the blood pressure is increased the filtration rate is restored resulting in optimum amount of urine output.

The function of the eye is to see the objects around. Eye has retina which contains photoreceptors rods and cones. Where as pupil is the small narrow aperture to the eye which allows light rays to enter in to the eye and fall on the receptors for seeing the objects. For optimum vision and protection of the eyes, the size of the pupil changes based on the amount of light in the surroundings. When we enter in to a dark room, the size of the pupil widens so that maximum light rays can enter and the vision is clear. The variation in size of the pupil is brought by a reflex action which is under the control of the nervous system.

This is how the kidnyes are bringing the optimum response by producing hormones and eye is bringing optimum response by a reflex circuit it has.