Atrial and pulmonary reflexes regulate blood pressure

2021-05-26 01:46 PM

There are tension receptors in the walls of the atria and pulmonary arteries, called hypotensive receptors, which are like those of the great circulatory arteries.

There are tension receptors in the walls of the atria and pulmonary arteries called hypotensive receptors, which are like those of the great circulatory arteries. Pressure-reducing receptors play an important role in minimizing changes in blood pressure in response to changes in blood volume. For example, if 300ml of blood is given to a dog with the receptors intact, the blood pressure will only increase by 15mmHg. When cutting the nerve of the receptor, blood pressure increases by about 40 mmHg, and when cutting the receptor to reduce pressure, blood pressure increases by about 100 mmHg.

Renal-activated atrial reflex - volume reflex

The distension of the atria always causes a reflex to dilate the afferent renal arterioles. Simultaneous signals are transmitted from the atria to the hypothalamus to decrease ADH secretion. The decrease in resistance of the afferent arterioles causes an increase in glomerular capillary pressure, which increases the amount of fluid filtered into the renal tubules. A decrease in ADH reduces water reabsorption from the renal tubules. The two combined effects - increased glomerular filtration, decreased fluid reabsorption - increase renal fluid loss thereby reducing blood volume to normal (atrial distension due to increased blood volume releases A hormone that acts on the kidneys is an atrial natriuretic peptide, which causes extra fluid to be excreted in the urine and blood volume returned to normal.

All the mechanisms that return blood volume to normal in the presence of variolization indirectly return blood pressure to normal, because increased volume increases blood flow and leads to hypertension. The volume reflex mechanism, along with other mechanisms of blood volume regulation.

An atrial reflex that controls heart rate (Bainbridge reflex)

Hypertension always causes an increase in heart rate, which can sometimes increase by 75%. Part of this increase is caused by the direct effect of an increase in atrial volume on sinus node tension (15%), 40-60% of the increase is caused by a nerve reflex known as the reflex. Bainbridge radiation. The tension of the atria generates a signal that is transmitted through the X cord to the medulla oblongata. The signal is then transmitted back to the X cord and sympathetic fibres to increase heart rate and force of contraction. Thus, this reflex prevents damage to the veins, atria, and pulmonary circulation.