AV Valves and Cardiac Function

The video explains the structure and function of the ventricles, focusing on the trabeculae carneae, papillary muscles, and chordae tendineae. It describes how these structures work together to ensure the proper functioning of the atrioventricular (AV) valves during the cardiac cycle. The papillary muscles contract to pull on the chordae tendineae, preventing the AV valves from inverting and allowing backflow of blood into the atria during ventricular contraction. This coordination is crucial for maintaining efficient blood flow and preventing regurgitation.

What are the ridges inside the ventricles called?

• Papillary muscles

• Trabeculae carneae

• Chordae tendineae

• AV valves

What connects the trabeculae carneae to the AV valves?

• Atrial muscles

• Ventricular walls

• Chordae tendineae

• Papillary muscles

What is the function of chordae tendineae?

• To open the AV valves

• To connect papillary muscles to the ventricular walls

• To contract the ventricles

• To prevent AV valves from inverting

What is the role of papillary muscles during ventricular relaxation?

• 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

What happens to the chordae tendineae when ventricles are relaxed?

• They expand

• They are tightened

• They are loose

• They contract

Why is it important for AV valves to remain closed during ventricular contraction?

• 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

What would happen if AV valves opened during ventricular contraction?

• Blood would flow into the ventricles

• Ventricles would expand

• Blood pressure would decrease

• Blood would flow back into the atria

What happens to papillary muscles when ventricles contract?

• They relax and lengthen

• They expand and thicken

• They remain unchanged

• They contract and shorten

What ensures that AV valves stay closed during ventricular contraction?

• Tightening of chordae tendineae

• Contraction of atrial muscles

• Expansion of ventricles

• Relaxation of ventricular walls

What is the primary role of papillary muscles during ventricular contraction?

• To push blood into the atria

• To open the AV valves

• To relax the ventricles

• To pull down and tighten the chordae tendineae