Blood Vessels

These flashcards cover key terms and definitions related to blood vessels, including their structure and function, pressure concepts, and related medical conditions.

Tunica intima

The innermost layer of a blood vessel, made up of endothelium and supporting tissues.

Tunica media

The middle layer of a blood vessel, consisting primarily of smooth muscle and elastic fibers.

Tunica externa

The outermost layer of a blood vessel composed of connective tissue.

Elastic arteries

Arteries closest to the heart, large in diameter with thick walls rich in elastin, acting as pressure reservoirs.

Muscular arteries

Arteries further from the heart with a thick tunica media primarily composed of smooth muscle to distribute blood.

Capillaries

Microscopic blood vessels where exchange of gases, nutrients, and waste occurs between blood and tissues.

Venules

Small veins that form when capillaries merge, containing a little smooth muscle.

Veins

Blood vessels that carry blood back to the heart, featuring valves to prevent backflow.

Blood pressure

The force exerted by circulating blood on the walls of blood vessels.

Mean Arterial Pressure (MAP)

The average blood pressure in a person's arteries during one cardiac cycle.

Pulse pressure

The difference between systolic and diastolic blood pressure.

Baroreceptors

Sensory receptors that detect changes in blood pressure and help regulate it.

Chemoreceptors

Receptors that monitor chemical changes in the blood and can influence blood pressure.

RAAS (Renin-Angiotensin-Aldosterone System)

A hormone system that regulates blood pressure and fluid balance.

Capillary Exchange

The process by which nutrients, gases, and wastes are exchanged between blood and tissues through capillary walls.

Varicose veins

Dilated and twisted veins caused by incompetent valves that result in blood pooling.

Atherosclerosis

A condition characterized by plaque buildup within arterial walls leading to reduced blood flow.

Hypertension

Elevated blood pressure, generally defined as above 140/90 mm Hg.

Hypotension

Low blood pressure, generally defined as below 90/60 mm Hg.

Circulatory shock

A condition resulting from inadequate blood flow to organs and tissues, often caused by hemorrhage or heart conditions.