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Regulation of Blood Pressure (BP)

The mechanisms including hormonal and renal processes that maintain BP within normal ranges.

Hormonal Mechanism

Regulation of BP through the release of hormones affecting blood volume and peripheral resistance.

Norepinephrine

A hormone released by the adrenal medulla that increases cardiac output and causes vasoconstriction to raise BP.

Epinephrine

A hormone that enhances the sympathetic response and increases cardiac output, similar to norepinephrine.

Atrial Natriuretic Peptide (ANP)

A hormone released by atrial myocytes that promotes sodium and water excretion, lowering blood volume and BP.

Antidiuretic Hormone (ADH)

A hormone that causes kidneys to conserve water, increasing blood volume and BP.

Renin

An enzyme released by kidneys that catalyzes the production of angiotensin II, impacting blood pressure.

Angiotensin II

A hormone that increases BP by causing vasoconstriction and stimulating aldosterone release.

Direct Renal Mechanism

A method of stabilizing BP by adjusting kidney filtration and urine output based on blood pressure.

Indirect Renal Mechanism

Regulation of BP via the renin-angiotensin-aldosterone mechanism.

Cardiac Output

The volume of blood the heart pumps in a given time period, determined by heart rate and stroke volume.

Tissue Perfusion

Local blood flow within tissues necessary for oxygen delivery, nutrient absorption, and waste removal.

Autoregulation

The intrinsic ability of tissues to regulate their own blood flow based on metabolic needs.

Metabolic Controls of Autoregulation

Regulatory mechanism responding to oxygen and nutrient levels in tissues to adjust blood flow.

Myogenic Controls of Autoregulation

Response of vascular smooth muscle to changes in stretch, leading to adjustments in blood flow.

Hypotension

Abnormally low blood pressure, potentially causing inadequate oxygen delivery to tissues.

Hypertension

High blood pressure, defined as systolic > 130 mm Hg or diastolic > 80 mm Hg.

Vasodilation

The widening of blood vessels, often resulting from metabolic signals that increase blood flow.

Vasoconstriction

The narrowing of blood vessels, which increases resistance and can lead to higher BP.

Fluid loss from hemorrhage

A condition leading to decreased blood volume and consequently lowered blood pressure.

Baroreceptors

Sensory receptors that detect changes in arterial blood pressure through stretch in the arterial walls.

Chemoreceptors

Sensory receptors that respond to changes in chemical compositions of the blood, such as oxygen and CO2 levels.

Crisis stressors

Occurrences like exercise and trauma that significantly affect blood pressure and cardiovascular response.

Angiogenesis

The formation of new blood vessels from existing ones, often occurring in response to increased tissue needs.

Circulatory Shock

A condition where tissue perfusion is inadequate to meet the cellular requirements for oxygen and nutrients.

Hypovolemic Shock

Shock resulting from significant fluid loss, leading to decreased blood volume and pressure.

Cardiogenic Shock

Shock caused by the heart's inability to pump effectively, leading to insufficient blood flow.

Vascular Shock

Condition marked by normal blood volume but extreme vasodilation, which lowers blood pressure.

Peripheral Resistance

The resistance to blood flow in the vessels, influenced by vessel diameter and blood viscosity.

Tissue Damage and Inflammatory Mediators

Chemicals released that can induce vasodilation and increase local blood flow to damaged tissues.

Oxygen and Nutrient Levels

Critical factors in determining tissue perfusion and initiating autoregulatory mechanisms.