Blood pressure fluctuates every moment but it is set to the normal point by our body by 2 processes.

1)short term regulation

2)long term regulation

Short term regulation of blood pressure:

Short term regulation of blood pressure is achieved by

•changing the blood vessels diameter

•changing the contractility of the heart

•changing the heart rate.

Baroceptors sense the blood pressure and then increase or decrease to the normal point.

Mechanism of increasing the blood pressure:

How blood pressure is increased?

If blood pressure is decreased, blood flow is also decreased and no stretching and baroceptors sends signals to nucleus tractus salitarious,  release nor epinephrine binds with B1 receptors on myocardium, heart rate and fore of contraction in increased thus increasing the blood pressure.

How blood pressure is decreased by norepinephrine?

OR

How blood pressure is increased by B1 receptors?

Whenever blood pressure is decrease the sympathetic nervous system is activated and parasympathetic nervous system is inhibited.

Sympathetic nervous system activates and release epinephrine or norepinephrine which act on the B1 receptors which are present on myocardium thus increasing the production of adenylate cyclase.

Adenylate cyclase increased the production of CAMP which releases calcium ions and thus contractility , SV , HR , COP all are increasing and thus increasing the blood pressure.

How blood pressure is increased by alpha 1 receptors?

Whenever decreased in blood pressure sympathetic nervous system is activated which release epinephrine/norepinephrine which stimulates the alpha 1 receptors on blood vessels.

Alpha 1 receptors are positively coupled with phospholipase C . Phospholipase C is activated which convert PIP2 (phospho inositol diphosphate) into IP3 (inositol triphosphate) and DAG (di acyl glycerol).

IP3 receptors present on endoplasmic Reticulum which releases the calcium ions. When calcium ions increase, contractility of smooth muscles of blood vessels is also increased.

Blood vessels constriction and diameter is reduced thus total peripheral resistance,  HR in increased and increasing the blood pressure.

Mechanism of decreasing the blood pressure:

How blood pressure is decreased?

If blood pressure is increased baroceptors stretch and activated, send signals to nucleus tractus salitarious which releases acetylcholine via vagul nerve which binds with M2 on heart which decreases the blood pressure.

How Blood pressure is decreased by M2 receptors?

OR

How blood pressure is decreased by acetylcholine?

Whenever there is increase in blood pressure, the blood pressure is sense by baroceptors  which send signals to the CNS . In CNS particularly area which is known as nucleus tractus salitarious present in medulla oblingeta and then sympathetic out put is inhibited and the parasympathetic output is increased.

Sympathetic nervous system is inhibited and parasympathetic nervous system is activated to reduce the blood pressure.

Muscarinic 2 receptors are present on myocardium . Parasympathetic nervous system activates the M2 receptors by acetylcholine.

M2 receptors are inhibitory receptors which inhibit the adenylate cyclase . When adenylate cyclase is inhibited there is no formation of CAMP.

CAMP is secondary messenger and it is responsible for releasing the calcium ions from endoplasmic Reticulum and calcium ions are necessary for the contraction of myocardium.

Whenever there is no release of CAMP there will be no calcium ions for myocardium contraction thus heart rate , heart contractility,  cardiac output is decreased and as a result blood pressure will be decreased.

Learn more

Searching Tags

How blood pressure is maintained?

How blood pressure is set to normal point?

How our body respond to fluctuations in blood pressure?

How our body regulate blood pressure?

Short term regulation of blood pressure

How blood pressure is regulated?

How many processes involved in regulating the blood pressure?

How short term regulation of blood pressure is achieved?

Mechanism of increasing the blood pressure

How blood pressure is increased?

How blood pressure is increased by B1 receptors?

How blood pressure is increased by norepinephrine?

How blood pressure is increased by epinephrine?

How blood pressure is increased by sympathetic nervous system?

Mechanism of decreasing the blood pressure

How blood pressure is decreased?

How blood pressure is decreased by M2 receptors?

How blood pressure is decreased by acetylcholine?

How blood pressure is decreased by parasympathetic nervous system?