Arterial blood pressure (ABP) is defined as the hydrostatic pressure exerted by the blood on the walls of the arteries. A typical blood pressure of a healthy adult is 120mm Hg systolic and 80 mm Hg diastolic. However, this regularly changes in response to the needs of the body (e.g. under exercise blood pressure increases to supply the increased demand for oxygen to the tissues). ABP is dependent on the cardiac output of the heart (CO) and peripheral resistance (PR). Because ABP is proportional to both CO and PR we can use a formula to calculate ABP:

Since cardiac output is equal to heart rate x stroke volume, an increase in either of these factors would lead to an increase in CO, which would lead to an increase in ABP. Likewise an increase in any of the factors that cause peripheral resistance (vasodilation of arterioles, length of blood vessels and blood viscosity) would lead to an increase in ABP.

Blood pressure can change dramatically under certain circumstances. For example, blood pressure would drop if someone were haemorrhaging seriously and losing a lot of fluids, so the body needs to be able to regulate blood pres

BHP is the capillary blood pressure, which is the overall hydrostatic pressure of the capillary fluid and solutes exerted out into the interstitial fluid. Typical values for this vary from 37 mmHg at the arterial end of the capillary to 17 mmHg at the venous end.

Baroreceptors are specially adapted nerve endings sensitive to the stretching of blood vessel walls. They are located in large populations in the aortic arch and the carotid arteries, as well as in smaller numbers in other arteries found in the chest and neck. Baroreceptors are constantly emitting action potentials, but an increase in arterial blood pressure would cause an increase of stretching of the arterial wall, which would stimulate the baroreceptors to increase the frequency of the action potentials. Conversely, a decrease in ABP would lead to a decrease in the frequency of the action potentials.

· Capillary fluid shift mechanism that works over minutes and hours

sure to be able to maintain circulation. A number of mechanisms have evolved to regulate ABP over short, medium and long term time periods:

Renin acts on angiotensinogen (from the liver) and cleaves off angiotensin I; a ten amino acid long polypeptide. A further two amino acids are removed from angiotensin I in the lungs by angiotensin converting enzyme (ACE). This converts angiotensin I into the eight amino acid long angiotensin II.

Some topics in this essay:
OP+IFHP BHP, Reflex Baroreceptors, Renin-Angiotensin Mechanism, Angiotensin II, Shift Capillary, ABP Blood, Pressure Arterial, Overall ABP, CO PR, blood pressure, ABP Likewise, interstitial fluid, angiotensin ii, capillary fluid, arterial blood, arterial blood pressure, renin-angiotensin mechanism, heart rate, regulate blood pressure, fluid shift, vasomotor control, impulses baroreceptors, capillary fluid shift, exerted interstitial fluid, heart rate stroke,