AV Valves and Cardiac Function

Papillary muscles

Trabeculae carneae

Chordae tendineae

AV valves

Atrial muscles

Ventricular walls

Chordae tendineae

Papillary muscles

To open the AV valves

To connect papillary muscles to the ventricular walls

To contract the ventricles

To prevent AV valves from inverting

They relax and pull on chordae tendineae

They contract to close AV valves

They relax and do not pull on chordae tendineae

They contract to open AV valves

They expand

They are tightened

They are loose

They contract

To allow blood to flow into the atria

To prevent blood from flowing back into the atria

To increase blood pressure in the atria

To decrease blood pressure in the ventricles

Blood would flow into the ventricles

Ventricles would expand

Blood pressure would decrease

Blood would flow back into the atria

They relax and lengthen

They expand and thicken

They remain unchanged

They contract and shorten

Tightening of chordae tendineae

Contraction of atrial muscles

Expansion of ventricles

Relaxation of ventricular walls

To push blood into the atria

To open the AV valves

To relax the ventricles

To pull down and tighten the chordae tendineae