Structure and Function of Blood Vessels chapter 20

These flashcards cover key vocabulary terms related to the structure and function of blood vessels, including types, layers, functions, pressures, and regulatory mechanisms.

Arteries

Blood vessels that transport blood away from the heart.

Capillaries

Microscopic porous blood vessels where exchange of substances between blood and tissues occurs.

Veins

Blood vessels that transport blood back to the heart.

Tunica interna

Innermost layer of blood vessels, consisting of simple squamous epithelium.

Tunica media

Middle layer of blood vessels, composed of circularly arranged smooth muscle cells and elastic fibers.

Tunica externa

Outer layer of blood vessels made up of connective tissue that helps anchor vessels to surrounding structures.

Companion vessels

Arteries and veins that supply the same body region and tend to lie next to each other.

Vasoconstriction

The narrowing of blood vessels due to contraction of smooth muscle in the tunica media.

Vasodilation

The widening of blood vessels due to relaxation of smooth muscle in the tunica media.

Capillary beds

Groups of capillaries functioning together, fed by a metarteriole.

Precapillary sphincter

Smooth muscle ring at the origin of true capillaries that regulates blood flow into capillary beds.

Systolic pressure

The pressure in the arteries during ventricular systole.

Diastolic pressure

The pressure in the arteries during ventricular diastole.

Pulse pressure

The difference between systolic and diastolic blood pressure.

Hydrostatic pressure

The physical force exerted by fluid (blood) against the walls of blood vessels.

Colloid osmotic pressure

The pressure exerted by proteins in the blood plasma that draw water into the circulatory system.

Hepatic portal system

The system of veins that carries blood from the digestive organs to the liver.

Renin-angiotensin system

A hormone system that regulates blood pressure and fluid balance.

Aldosterone

A hormone that increases sodium and water reabsorption in the kidneys to increase blood volume.

Antidiuretic hormone (ADH)

A hormone that promotes water reabsorption in the kidneys and vasoconstriction to increase blood pressure.