Heart Valves and Venous Valves

Created by BethRN08 

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Heart Valves

Ensure unidirectional blood flow through the heart

Atrioventricular (AV) valves

located at each atria ventricular junction
Prevent backflow into the atria when ventricles contract

Atrioventricular (AV) valves

Tricuspid valve: R AV valve

Atrioventricular (AV) valves

Mitral valve: L AV valve

Chordae tendineae

collagen cords attached to AV valve flap
Anchor AV valve cusps to papillary muscle
In their absence, flaps would be blown upward into atria upon contraction

During heart relaxation

AV valve flaps hang loosely into the ventricular chambers

During heart contraction

intraventricular pressure rises, forcing blood against the valve flaps *closes the flaps

Semilunar (SL) valves

Aortic/Pulmonary valves

Semilunar (SL) valves

Guard arteries from the ventricles aorta/pulmonary trunk

Semilunar (SL) valves

Prevent backflow into the ventricles when ventricles relax

Semilunar (SL) valves

Each valve consists of 3 cusps; Open and close in response to pressure

Semilunar (SL) valves

Ventricular contraction and increase in intraventricular pressure--> valves open, cusps flatten against their respective arterial walls; Blood flows into vessels

Semilunar (SL) valves

Ventricles relax, blood flows back toward the heart ==> valves close

Venous Valves

Form from folds of the tunica intima
Resemble semilunar heart valves

Venous Valves

Prevent blood from flowing backwards

Venous Valves

Most abundant in veins against gravity

Venous Valves

Assist in blood flow against gravity
Absent in thoracic and abdomenal cavity veins

Venous Valves

Leaky valves results in varicose veins

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