Arterial walls are stretched stimulating, baroreceptors in the carotid sinus aortic arch and other large arteries of the neck and thorax.

 As a result these receptors send off a faster stream of impulses to the brain.

 Let’s observe these nerve impulses travel to the brain in response to increased stimulation from the barrel receptors. 

1. the brain increases parasympathetic activity 
2. decreases sympathetic activity.

 

 This leads to a reduction in heart rate and increase in the diameter of the arterials and therefore lower blood pressure.

 Blood pressure back down to normal levels. 

 

Let’s look at the effect of increased parasympathetic and decreased sympathetic activity on the heart and blood pressure with increased activity of the vagus nerve which is part of the parasympathetic nervous system and decreased activity of the sympathetic cardiac nerve heart rate is reduced. This leads to lower cardiac output and therefore lower lower blood pressure , let’s observe the nerve impulses and the effect on heart rate and blood pressure. Let’s look at the effective decreased sympathetic activity on arterials and blood pressure, vasomotor, fibbers or sympathetic nerves that innovate the smooth muscle of blood vessels with decreased activity of vasal motor fires, the vascular smooth muscle relaxes arterial diameter increases in blood pressure is reduced  The short term regulation of rising blood pressure in response to rising blood pressure, receptor stretch, increasing impulses to the brain. This leads to increased parasympathetic activity and decreased sympathetic activity resulting in slowing of the heart rate and increased in the diameter of the arterials, and consequently, a reduction in blood pressure  Now let’s look at the short term regulation of falling blood pressure when blood pressure drop. Suddenly the barrel receptors are inhibited and they send fewer impulses to the brain as a result, parasympathetic activity decreases and

 sympathetic activity increases leading to an increase in blood pressure via three mechanisms 

(1)increased sympathetic impulses to the heart, increased heart rate and contract 

(2) increased impulses to the blood vessels increase vasoconstriction. 

(3)increased sympathetic impulses to the adrenal gland, stimulate the release of epinephrine and epinephrine into the bloodstream. These hormones enhance heart rate, contractility and basal constriction together. 

These three mechanisms bring blood pressure back up to normal levels as illustrated on the following screens.

First, let's look at the effective increased sympathetic activity on the heart and blood pressure increased sympathetic impulses to the heart and decreased vagus nerve activity lead to increased heart rate and enhanced contractility increasing stroke volume. These changes result in higher cardiac output which increases blood pressure. Let's observe the response to declining blood pressure and the effect on heart rate and blood pressure. 

How does greater sympathetic activity affect arteries and blood pressure?

Motor fibre activity leads to constriction of vascular smooth-muscle. The smaller arterial or diameter gives rise to increase blood pressure. Now, let's explore the effective increased sympathetic activity on the adrenal gland and blood pressure increased sympathetic impulses to the adrenal gland, stimulate the release of epinephrine, and nor epinephrine into the bloodstream, these hormones increase heart rate contractility of the heart and vasoconstriction of blood vessels thus increasing blood pressure, because they are carried in the blood, these hormones act more slowly than nervous system controls and the effects are more prolonged. Let's watch the response to falling blood pressure. Here's a recap of short term regulation of falling blood pressure as blood pressure, Falls barrel receptors are inhibited, resulting in decreased impulses to the brain  Parasympathetic activity is decreased and sympathetic activity is increased leading to increased heart rate and contractility increased construction and the release of epinephrine and epinephrine from the adrenal gland. All of these mechanisms contribute to raising blood pressure Backup to normal levels.