The Blood Vessels and Circulatory System

This set of flashcards focuses on key concepts related to blood vessels and the circulatory system, providing definitions that will aid in understanding critical terms for the upcoming exam.

Tunica Interna (Tunica Intima)

The innermost membrane of the blood vessel, lined with endothelium, a basement membrane, and internal elastic lamina, reducing friction as blood moves.

Tunica Media

The middle layer of the blood vessel, primarily composed of smooth muscle and elastic tissue, controlling blood pressure and flow.

Tunica Externa (Tunica Adventitia)

The outer layer of the arterial wall made of connective tissue, providing support and containing vasa vasorum.

Vasoconstriction

Reduction in the lumen diameter of a blood vessel due to smooth muscle contraction, resulting in increased resistance and blood pressure.

Vasodilation

Widening of the lumen of a blood vessel due to smooth muscle relaxation, leading to decreased resistance and blood pressure.

Arteries

Blood vessels that carry blood away from the heart, typically containing oxygen-rich blood, with the exception of the pulmonary artery.

Arterioles

Small arteries that branch off from larger arteries and feed into capillaries, playing a critical role in regulating blood flow and pressure.

Capillaries

The smallest blood vessels where the exchange of nutrients and wastes occurs between blood and tissues.

Venules

Small veins that carry blood toward the heart from capillaries, merging to form larger veins.

Veins

Blood vessels that carry blood toward the heart, typically containing oxygen-poor blood, with the exception of pulmonary veins.

Blood Pressure

The force exerted by circulating blood on the walls of blood vessels, commonly measured in millimeters of mercury (mmHg).

Hypertension

A condition characterized by consistently high blood pressure, potentially leading to serious health issues.

Circulatory Shock

A condition where blood vessels are inadequately filled and blood cannot circulate normally, risking tissue death.

Hepatic Portal System

A portal system that carries nutrient-rich blood from the gastrointestinal tract to the liver for processing.

Pulmonary Circuit

The part of the circulatory system that carries deoxygenated blood from the right side of the heart to the lungs and back to the left side.

Systemic Circuit

The part of the circulatory system that delivers oxygen-rich blood from the left side of the heart to the rest of the body.

Anastomosis

The connection between two blood vessels, providing alternative pathways for blood flow, especially during compromise.

Cardiac Output

The volume of blood the heart pumps per minute, a crucial factor influencing blood flow and pressure.

Peripheral Resistance

Resistance that blood encounters in the systemic circulation as it moves through blood vessels.

Mean Arterial Pressure (MAP)

The average pressure in a person's arteries during one cardiac cycle; a crucial measure for assessing blood flow.

Capillary Dynamics

The mechanisms governing the exchange of materials between blood and tissues, influenced by hydrostatic and osmotic pressures.