angiotensin
(noun)
any of several polypeptides that narrow blood vessels and thus regulate arterial pressure
Examples of angiotensin in the following topics:
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Long-Term Renal Regulation
- Consistent and long-term control of blood pressure is determined by the renin-angiotensin system.
- A key modulator of blood viscosity is the renin–angiotensin system (RAS) or the renin–angiotensin–aldosterone system (RAAS); a hormone system that regulates blood pressure and water balance.
- Angiotensin I is subsequently converted to angiotensin II by the enzyme angiotensin converting enzyme found in the lungs.
- If the renin–angiotensin–aldosterone system is too active, blood pressure will be too high.
- It is believed that angiotensin I may have some minor activity, but angiotensin II is the major bio-active product.
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Other Hormonal Controls for Osmoregulation
- The renin-angiotensin-aldosterone system (RAAS) stabilizes blood pressure and volume via the kidneys, liver, and adrenal cortex.
- The renin-angiotensin-aldosterone system (RAAS) is a hormone system that regulates blood pressure and water (fluid) balance .
- This system proceeds through several steps to produce angiotensin II, which acts to stabilize blood pressure and volume.
- After renin facilitates the production of angiotensis I, angiotensin converting enzyme (ACE) then converts angiotensin I to angiotensin II.
- The renin-angiotensin-aldosterone system increases blood pressure and volume.
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Sodium Balance Regulation
- Extra sodium is lost from the body by reducing the activity of the renin-angiotensin-aldosterone system which leads to increased sodium loss from the body.
- The major physiological controller of aldosterone secretion is the plasma angiotensin II level which increases aldosterone secretion.
- A low renal perfusion pressure stimulates the release of renin, which forms angiotensin I which is converted to angiotensin II.
- In addition to aldosterone and angiotensin II other factors influence sodium excretion.
- Regulation of sodium via the hormones renin, angiotensin, and aldosterone.
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Nonrespiratory Air Movements
- ACE (angiotensin converting enzyme) is an enzyme secreted by the endothelial cells of the capillaries in the lungs.
- ACE converts angiotensin I into angiotensin II, which are two important hormones in the renin-angiotensin feedback loop of the renal system.
- In general, more ACE leads to more angiotensin II, which leads to more aldosterone, which leads to more retained water through sodium reabsorption in the kidney, which leads to increased blood volume and blood pressure.
- The Renin-Angiotensin System is dependent on ACE from the lungs to regulate blood pressure.
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Adrenal Cortex
- The cortex is regulated by neuroendocrine hormones secreted by the pituitary gland which are under the control of the hypothalamus, as well as by the renin-angiotensin system.
- The major stimulus to produce aldosterone is angiotensin II while ACTH from the pituitary only produces a transient effect.
- Angiotensin is stimulated by the juxtaglomerular cells when renal blood pressure drops below 90 mmHg.
- Its secretion is regulated by the oligopeptide angiotensin II (angiotensin II is regulated by angiotensin I, which in turn is regulated by renin).
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Hormonal Regulation of the Excretory System
- When blood pressure drops, the renin-angiotensin-aldosterone system (RAAS) is activated.
- When angiotensinogen is cleaved by renin, it produces angiotensin I, which is then converted into angiotensin II in the lungs.
- Angiotensin II, in addition to being a potent vasoconstrictor, also causes an increase in ADH and increased thirst, both of which help to raise blood pressure.
- Angiotensin II stimulates release of these hormones.
- Angiotensin II, in turn, is formed when renin cleaves angiotensin.
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Developmental Changes in Fluids
- Hormonal mechanisms including the renin-angiotensin system, aldosterone, and vasopressin are involved in modifying fetal renal excretion, reabsorption of sodium and water, and regulation of vascular volume.
- Overview of the renin-angiotensin system that regulates blood pressure and water (fluid) balance.
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Regulation of Water Output
- A fluid-insufficiency causes a decreased perfusion of the juxtaglomerular apparatus in the kidneys, activating the renin-angiotensin system.
- The activated renin-angiotensin system stimulates zona glomerulosa of the adrenal cortex, which in turn secretes hormone aldosterone.
- Overview of the renin-angiotensin system that regulates blood pressure and water (fluid) balance.
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Overview of the Adrenal Glands
- The cortex is regulated by neuroendocrine hormones secreted from the pituitary gland which are under the control of the hypothalamus, as well as by the renin-angiotensin system.
- The major stimulus to produce aldosterone is angiotensin II while ACTH from the pituitary only produces a transient effect.
- Angiotensin is stimulated by the juxtaglomerular cells when renal blood pressure drops below 90 mmHg.
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Congestive Heart Failure
- Reduced perfusion (blood flow) to the kidneys stimulates the release of renin – an enzyme that catalyzes the production of the potent vasopressor angiotensin .
- Angiotensin and its metabolites cause further vasoconstriction, and stimulate increased secretion of the steroid aldosterone from the adrenal glands.
- Reduced perfusion (blood flow) to the kidneys stimulates the release of renin, an enzyme that catalyzes the production of the potent vasopressor angiotensin.