1. With your right shoulder and hip firmly against a wall, it is virtually impossible to lift the left leg without falling over. This is because the wall interferes with the crossed extensor reflex, which would ordinarily shift the body's weight over the right leg and enable you to keep your balance when lifting the left.

2. Somatic and visceral reflexes differ mainly in the types of effectors involved–voluntary (skeletal) muscle for somatic reflexes and involuntary (smooth and cardiac) muscle and glands in visceral reflexes. In spite of their differences, both types of reflexes involve involuntary responses and simple neural pathways (reflex arcs).

3. Vapors from the onion irritate nerve endings at the surface of the eye. Signals are conducted through the ophthalmic division of the trigeminal nerve to the pons of the brainstem, then back through the facial nerve to the tear glands.

4. (a) The trigeminal nerve; (b) the glossopharyngeal nerve; (c) the vagus nerve

5. It will cause paralysis of the right side of the diaphragm and reduce ventilation of the right lung. Intercostal and other muscles also carry out pulmonary ventilation, so ventilation will not completely stop. The left lung will not be affected.

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