Question

Atrioventricular valves close at the beginning and the semilunar valves open at the end of which stage of the cardiac cycle?

		ejection
		isovolumic relaxation
		ventricular systole
		isovolumic contraction

Which of the following will induce the strongest conscious perception of suffocation?

		high blood carbon dioxide
		low blood oxygen
		high blood pH

If an individual were confined in a small space, and re-inspiring expired gasses, which of the following would be expected?

		a sense of suffocation
		high pH
		low blood carbon dioxide

Which of the following would result if one were to breathe an atmosphere with normal oxygen levels, but excessive carbon dioxide levels?

		depressed respiratory rate
		low pH
		remarkably reduced blood oxygen

In which of the following situations would blood pH be low?

		the manure pit
		the non-pressurized aircraft cabin
		the Apollo 13 capsule

Which of the following is NOT used by the cerebellum to maintain balance?

		gustatory
		proprioception
		vestibular function
		vision

How many forms of sensory feedback is the cerebellum of a blind individual with a vestibular deficit receiving?

		zero
		one
		two
		three

An intention tremor and ataxia are consistent with which of the following?

		a basal ganglion lesion
		a proprioceptive deficit
		a vestibular deficit
		a cerebellar lesion

A positive Rhomberg sign along with an inability to judge the position of a limb or digit suggests which of the following?

		a basal ganglion lesion
		a proprioceptive deficit
		a cerebellar lesion
		a vestibular deficit

A resting tremor is consistent with which of the following?

		a proprioceptive deficit
		a basal ganglion lesion
		a cerebellar lesion
		a vestibular deficit

Which of the following hormones inhibits prolactin secretion?

		dopamine
		TRH
		OT
		VIP

Answer 1

1) Ventricular systole

During the ventricular systole, there is increase in the pressure in the ventricles and hence it tends to increase the blood pumping from right ventricle and into the aorta from left ventricle. During the beginning of the ventricular systole, the atrioventricular (AV) valves close which is the tricuspid valve located between right atrium and right ventricle. The AV valves tends to relax and prevent the back flow of the blood. The semi-lunar valves open at the beginning of ventricular systole which is present between left and right ventricle and it opens with the increase in the pressure in the ventricles. It opens when the ventricles contraction applying a pressure opening the semilunar valves.

The second option is not correct as isovolumic relaxation is the time which occurs between end of aortic ejection and as the ventricular filing starts. It is the time that follows from the closure of the aortic valve to the beginning of opening of the mitral valve.

The first option of ejection is not correct because this basically refers to the amount of the blood which is pumped out of the ventricles. In most of the term ejection term is something which is referred to left ventricular ejection or pumping out of blood.

The last option of isovolumic contraction is an event in which there is no change in the volume of the ventricles despite the rise and increase in the ventricular pressure. Hence this is not the correct answer.