Asked by Kayla Matusz on Apr 27, 2024
Verified
Contraction of the papillary muscles would
A) eject blood from the ventricles.
B) prevent the AV valves from protruding into the atria.
C) close the semilunar valves.
D) cause the atria to eject their contents into the ventricles.
E) open the semilunar valves.
Papillary Muscles
Muscles located in the ventricles of the heart, attaching to the cusps of the atrioventricular valves via chordae tendineae and preventing valve inversion.
AV Valves
The atrioventricular valves, consisting of the tricuspid and mitral valves, are located between the atria and ventricles in the heart, regulating blood flow and preventing backflow.
Semilunar Valves
Heart valves located at the bases of the aorta and the pulmonary artery that prevent backflow of blood into the ventricles during systole by opening to allow blood ejection and closing during diastole.
- Comprehend the importance of cardiac electrical activity, emphasizing the roles of the SA node, AV node, and the function of papillary muscles.
Verified Answer
PG
Peter GiammonaMay 01, 2024
Final Answer :
B
Explanation :
The contraction of the papillary muscles occurs during ventricular contraction. Their primary function is to pull on the chordae tendineae, which are attached to the atrioventricular (AV) valves (mitral and tricuspid valves), preventing these valves from inverting or protruding into the atria when the ventricles contract. This action ensures that blood flows in the correct direction, from the ventricles into the outflow tracts (towards the pulmonary artery and aorta), and does not backflow into the atria.
Learning Objectives
- Comprehend the importance of cardiac electrical activity, emphasizing the roles of the SA node, AV node, and the function of papillary muscles.