CVS 7

Flashcards covering the structure and function of the circulatory system, including blood vessels, blood pressure, and related pathologies.

Circulatory System Function

To deliver blood to tissues and allow exchange of blood gases, nutrients, and waste products.

Venous System

Part of the circulatory system responsible for returning blood to the heart.

Arterial System

Part of the circulatory system responsible for delivering blood away from the heart.

Elastic Arteries

Arteries with thick walls and a tunica media containing elastic tissue; conduct blood away from the heart and withstand pressure changes.

Muscular Arteries

Arteries with a tunica media containing mainly smooth muscle tissue; divert blood to areas that need increased flow.

Arterioles

Small arteries with a tunica media containing mainly smooth muscle tissue; important for blood pressure regulation.

Capillaries

Blood vessels that allow two-way exchange of materials; consist of endothelium surrounded by a thin basement membrane.

Venules

Small veins that collect blood from capillaries.

Medium Veins

Carry blood towards the heart, have thinner walls and contain valves to prevent backflow.

Large Veins

Major veins that return blood to the heart.

Tunica Intima

The innermost layer of an artery, consisting of endothelium and a basement membrane.

Tunica Media

The middle layer of an artery, consisting of smooth muscle and connective tissue.

Tunica Externa

The outermost layer of an artery, consisting of connective tissue and nerve fibers; may contain vaso vasorum in larger vessels.

Vasoconstriction

Contraction of smooth muscle in the tunica media, reducing the diameter of a blood vessel.

Vasodilation

Relaxation of smooth muscle in the tunica media, increasing the diameter of a blood vessel.

Continuous Capillary

A capillary with no gaps between endothelial cells.

Fenestrated Capillary

A capillary with gaps (fenestrations/pores) between endothelial cells.

Sinusoids

Capillaries with large spaces between endothelial cells and no basement membrane.

Postcapillary Venules

Small venules, similar to capillaries, where exchange of material can take place.

Muscular Venules

Larger venules with thicker walls where no exchange can take place.

Venous Return

The blood flow returning to the heart.

Blood Pressure

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

Systolic Pressure

Pressure when ventricles contract.

Diastolic Pressure

Pressure when ventricles relax.

Pulse Pressure

Systolic pressure minus diastolic pressure.

Mean Arterial Pressure (MAP)

Diastolic pressure + (pulse pressure / 3).

Peripheral Resistance

The opposition to blood flow.

Atherosclerosis

Condition caused by the development of atheroma (build-up of material) in the arteries.

Cerebrovascular Accident (Stroke)

Possible consequence of atherosclerosis in the cerebral circulation, leading to neurological symptoms.

Myocardial Infarction

Possible consequence of atherosclerosis in the coronary circulation, caused by a blockage in the coronary arteries.