Introduction to Blood Vessels

This set of flashcards covers key terms and concepts related to the cardiovascular system and the function of blood vessels.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood to the heart.

Capillaries

Small blood vessels where chemical and gaseous exchange occurs between blood and interstitial fluid.

Vasoconstriction

The narrowing of blood vessels resulting from contraction of the muscular wall of the vessels.

Vasodilation

The widening of blood vessels resulting from relaxation of smooth muscle cells.

Precapillary sphincters

Muscles that regulate blood flow into capillary beds based on the physiological needs of the tissues.

Blood Pressure

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

Skeletal Muscle Pump

The mechanism of blood flow back to the heart aided by the contraction of skeletal muscles.

Respiratory Pump

The mechanism by which blood is pushed into the thoracic cavity during inhalation and returned during exhalation.

Varicose Veins

Swollen and twisted veins that occur when valves in the veins weaken and allow blood to pool.

Arteries

Blood vessels that carry blood away from the heart.

Arterioles

The smallest arterial branches that lead into capillary beds and are primary sites of resistance to blood flow.

Veins

Blood vessels that carry blood to the heart.

Venules

Small blood vessels that collect blood from capillaries and drain into veins.

Venous Valves

Internal folds of the tunica intima in veins that prevent the backflow of blood, ensuring one-way flow toward the heart.

Capillaries

Small blood vessels where chemical and gaseous exchange occurs between blood and interstitial fluid.

Continuous Capillaries

Capillaries with a complete endothelial lining, found in most regions of the body, allowing for the diffusion of water and small solutes.

Vasoconstriction

The narrowing of blood vessels resulting from contraction of the muscular wall of the vessels.

Vasodilation

The widening of blood vessels resulting from relaxation of smooth muscle cells.

Peripheral Resistance

The resistance to blood flow within the systemic circulation, primarily determined by the diameter of the arterioles.

Precapillary sphincters

Muscles that regulate blood flow into capillary beds based on the physiological needs of the tissues.

Blood Pressure

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

Systolic Pressure

The peak blood pressure measured in the arteries during ventricular contraction (P_{systolic}).

Diastolic Pressure

The minimum blood pressure measured in the arteries during ventricular relaxation (P_{diastolic}).

Skeletal Muscle Pump

The mechanism of blood flow back to the heart aided by the contraction of skeletal muscles.

Respiratory Pump

The mechanism by which blood is pushed into the thoracic cavity during inhalation and returned during exhalation.

Venous Return

The amount of blood arriving at the right atrium each minute, heavily influenced by the skeletal muscle and respiratory pumps.

Varicose Veins

Swollen and twisted veins that occur when valves in the veins weaken and allow blood to pool.

Tunica Media

The middle layer of a blood vessel wall containing sheets of smooth muscle and elastic fibers, responsible for vasoconstriction and vasodilation.

Hypertension

A chronic medical condition where blood pressure is abnormally high, typically defined as blood pressure above 130/80\text{ mmHg}.