Blood pressure is the pressure applied by blood on the walls of blood vessels, it is controlled by a negative feedback system where heart rate and blood volume need to be altered in order to control the pressure. Local negative feedback systems and heart rate is regulated but the cardiovascular centre which also in turn controls neural and hormonal mechanisms.
Neurons regulate heart rate and contractility and some neurons inhibit, stimulate or control heart rate by causing constriction which also controls the blood pressure.
The cardiovascular centre receives input responses from the brain via sensory receptors. The impulse travels from the cerebral cortex and hypothalamus to affect the cardiovascular centre.
Vasodilation of blood vessels …show more content…
Reduced heart rate leads to decreased cardiac output so the cardiovascular centre slows the rate of sympathetic impulses which causes vasoconstriction due to decreased sympathetic resistance which causes a decrease of arterial blood pressure. Baroreceptors are quick to counteract the drop in pressure but are slow in the elderly due to slower neural responses.
Chemoreceptors monitor changes in chemical composition of blood and are located by the baroreceptors of the carotid sinus and aortic arch. They are found in small structures called carotid bodies and aortic bodies. They can detect changes of oxygen, carbon dioxide and acid concentration in the blood.
Hormonal mechanisms also coordinate blood pressure for example when renin angiotensin-aldosterone blood volume decreases blood pressure also decreases so renin is secreted. The angiotensin-converting enzyme then produces a hormone called angiotensin 2 which increases the blood pressure. Vasoconstriction of blood vessel walls increases systemic vascular resistance and stimulates the secretion of aldosterone which increases the reabsorption of sodium ions and water. By increasing the reabsorption of water the total blood volume also increase which causes an increase of blood
Neurons regulate heart rate and contractility and some neurons inhibit, stimulate or control heart rate by causing constriction which also controls the blood pressure.
The cardiovascular centre receives input responses from the brain via sensory receptors. The impulse travels from the cerebral cortex and hypothalamus to affect the cardiovascular centre.
Vasodilation of blood vessels …show more content…
Reduced heart rate leads to decreased cardiac output so the cardiovascular centre slows the rate of sympathetic impulses which causes vasoconstriction due to decreased sympathetic resistance which causes a decrease of arterial blood pressure. Baroreceptors are quick to counteract the drop in pressure but are slow in the elderly due to slower neural responses.
Chemoreceptors monitor changes in chemical composition of blood and are located by the baroreceptors of the carotid sinus and aortic arch. They are found in small structures called carotid bodies and aortic bodies. They can detect changes of oxygen, carbon dioxide and acid concentration in the blood.
Hormonal mechanisms also coordinate blood pressure for example when renin angiotensin-aldosterone blood volume decreases blood pressure also decreases so renin is secreted. The angiotensin-converting enzyme then produces a hormone called angiotensin 2 which increases the blood pressure. Vasoconstriction of blood vessel walls increases systemic vascular resistance and stimulates the secretion of aldosterone which increases the reabsorption of sodium ions and water. By increasing the reabsorption of water the total blood volume also increase which causes an increase of blood