Question

Please provide a well contruted paragraph explaining the following:

4.)An individual stands up rapidly from a lying position and becomes light-headed due to a drop in blood pressure in the brain. This is known as postural hypotension. The body responds by triggering the baroreceptor reflex that targets the heart and blood vessels.

a. Explain how heart rate could be increased due to the baroreceptor reflex. Include which cells are involved and the electrical changes that occur in the cells to influence heart rate. Make sure to discuss what is happening at the cellular level and focus on specific ions/gated ion channels that affect membrane potential.

b. Explain how blood vessels would be affected by the baroreceptor reflex and why this would help alter blood pressure. What cells are functioning as the effectors in this mechanism and what are they doing?

Answer 1

Baroreceptor also called pressoreceptor are the sensors located in the blood vessels of all vertebrate animals.They sense blood pressure and relay information to brain,so that blood pressure can be maintained.They are a type of mechanoreceptors sensory neurons that are excited by a stretch of blood vessels that triggers increase in action potential generate rate provide information to central nervous system.

This sensory information used primarily in autonomic reflexes,inturn influence heart cardiac output and vascular smooth muscle to influence peripheral resistance.They act as a part of negative feedback mechanism systems called baroflex which means change in mean arterial .

Baroreceptor are of two types based on influence with blood pressure.they are

1.high pressure arterial system

2.low pressure arterial system.

CELLS involved with baroreceptor are aortic arch,carotid atria,vena cava,sinuses.

These are strecst receptors thar are stimulated by distortion of arterial walls when pressure changes.It can effect both average blood pressure or change in pressure.

Low pressure veins or vessels in the walls of right atrium and veins of heart.The low pressure baroreceptor are involved in regulation of blood vessel.The blood vessel determines mean pressure system.It also effects circulatory and renal effects.Also effects production of hormone secretion.It effects autonomic nervous system.

Arterial baroreceptor: distortion of arterial walls when pressure changes.Action potentials triggers in baroreceptor ending are directly conducted to the brain stem when central terminations or synapse transmit this information to neurons within a solitary nucleus.This reflex response triggers an increase or decrease action potential.

An increase in action potential in mean arterial pressure increases depolarization of this sensory endings resulting in action potentials.These action potential are conducted b axons and have a reflex effect on cardiovascular system.signals from carotid are sent via glossopharyngeal nerve and signals from aortic are sent to vagus nerve.Arterial baroreceptor inform reflex about arterial blood pressure but other stretch receptors in the large veins and right atrium xonvey information about low pressure parts of circulatory system.