Vascular System and Blood Pressure Regulation Vocabulary

A set of vocabulary flashcards covering blood vessel dynamics, resistance, velocity, atherosclerosis, and neural and hormonal regulation of blood pressure based on the provided notes.

Peripheral Resistance

The friction of blood against vessel walls that opposes blood flow, determined primarily by blood viscosity and vessel diameter.

Blood Viscosity

The thickness or stickiness of blood, primarily caused by the number of red blood cells, protein (albumin) levels, or dehydration.

Vasomotion

The process of adjusting blood vessel diameter via vasoconstriction or vasodilation to control peripheral resistance and blood pressure.

Vasoconstriction

The reduction of vessel diameter through vascular muscle contraction, which increases blood pressure and resistance while decreasing blood flow to tissues.

Vasodilation

The increase in vessel diameter resulting from vascular muscle relaxation, which decreases blood pressure and resistance while increasing blood flow to tissues.

Aortic Blood Velocity

The speed of blood flow in the aorta, which travels at approximately $1200\,mm/sec$ due to its large diameter and proximity to the left ventricle.

Capillary Blood Velocity

The speed of blood flow in capillaries, which slows to approximately $0.4\,mm/sec$ due to high resistance, distance from the heart, and a large total cross-sectional area.

Atherosclerosis

A cardiovascular disease responsible for $1$ out of every $3$ deaths in the United States, characterized by plaque buildup within arterial walls that obstructs blood flow and deteriorates vessel walls.

Fatty Streak

An early-stage atherosclerotic lesion formed when monocytes transform into macrophages and absorb cholesterol alongside smooth muscle cells, isolated by a fibrous cap.

Atheroma

An atherosclerotic plaque composed of lipids, smooth muscle cells, and macrophages that proliferates on damaged endothelium, obstructing the arterial lumen.

Arteriosclerosis

A condition resulting from atheroma accumulation that causes the arterial wall to become rigid.

Angina Pectoris

Chest pain and related symptoms that occur when the lumen of a major coronary artery is reduced by $75\%$ due to plaque buildup.

Autoregulation

An organ's intrinsic ability to adjust its own blood flow without neural or hormonal influence, operating most vigorously in the heart, brain, and kidneys.

Nitric Oxide

A powerful vasodilator secreted by endothelial cells lining blood vessels when surrounding tissues demand increased blood flow.

Endothelins

Powerful vasoconstrictive polypeptides secreted by endothelial cells lining blood vessels.

Reactive Hyperemia

A dramatic increase in blood flow to a specific area following a temporary blockage of its blood supply.

Vasomotor Center

An area located within the medulla of the brain that sends autonomic nervous system signals to alter blood vessel diameter and regulate blood pressure.

Baroreceptors

Pressure-sensing receptors located in the carotid sinus and aortic arch that transmit signals via the glossopharyngeal and vagus nerves to regulate blood pressure.

Aldosterone

A hormone secreted by the adrenal cortex when blood pressure drops, stimulating the kidneys to retain sodium and water to expand blood volume.

Antidiuretic Hormone (ADH)

A hormone secreted by the posterior pituitary gland during low body water content that promotes vasoconstriction and water retention.

Atrial Natriuretic Peptide (ANP)

A hormone released by the heart's atria in response to elevated blood pressure that induces vasodilation and stimulates renal excretion of sodium and water.

Angiotensin-Converting Enzyme (ACE)

An enzyme responsible for producing angiotensin II, a potent vasoconstrictor that raises blood pressure.