Archives: Questions and Answers

Explain how each of the following processes contributes to the maintenance of constant internal body temperature in mammals: (a) sweating (b) shivering (c) contraction of hair erector muscles (d) vasodilation and vasoconstriction of arterioles supplying skin surface capillaries

Describe the roles of the hypothalamus and of temperature receptors in the skin in maintaining a constant internal body temperature in mammals

Describe the role of insulation in maintaining a constant internal body temperature in mammals

Describe homeostasis as the maintenance of a constant internal environment

Compare nervous and hormonal control, limited to speed of action and duration of effect

Explain accommodation to view near and distant objects in terms of the contraction and relaxation of the ciliary muscles, tension in the suspensory ligaments, shape of the lens and refraction of light

Explain the pupil reflex in terms of light intensity and antagonistic action of circular and radial muscles in the iris

Identify, on a diagram, the structures of the eye, limited to: cornea, iris, pupil, lens, ciliary muscles, suspensory ligaments, retina, fovea, optic nerve and blind spot

Describe that synapses ensure that impulses travel in one direction only

Describe the events at a synapse: (a) an impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap (b) the neurotransmitter molecules diffuse across the gap and bind with receptor proteins (c) an impulse is stimulated in the next neurone