Question

Inserted on the flaps of bicuspid and tricuspid valves, the thread-like tendons present on the papillary muscles are known as
A. Chordae tendineae
B. Yellow elastin fibers
C. Reticular fibers
D. Collagen fibers

Answer 1

Hint: The papillary muscles, located in the ventricles of the heart, play an important role in normal cardiac function. These help to prevent leakage through the AV valves during systole. The mitral valve is also called the bicuspid valve because of the two leaflets or cusps. The tricuspid valve is on the right side of the heart and has three leaflets or cusps.

Complete answer: The thread-like tendons of papillary muscles prevent the valves of the heart from movement. By holding the flaps tightly against the strong flow of blood which are inserted upon the flaps of tricuspid and bicuspid valves that are known as chordae tendineae. They are tendinous structures that allow the blood to flow in one direction only.
While pumping the blood, it helps in the holding of the atrioventricular valves in place. The integral part of the chordae tendineae is formed by 20% elastin and 80% collagen and endothelial cells. These cord-like tendons hold in position other flaps such as bicuspid or mitral valve and prevent the flaps from being everted to the right atrium
Yellow elastic tissue enables organs and parts of organs to contract and stretch. The function of the organ involves movement includes expansion and contraction of membranes e.g. of lung tissue.
Reticular fibers crosslink to form a fine meshwork which is called reticulin. This crosslink network acts as a supporting mesh in soft tissues. These soft tissues include the liver, bone marrow, and the tissues and organs of the lymphatic system.
Hence, the correct answer is option A.

Note: The tricuspid and the bi-cuspid valves are atrioventricular valves. Papillary muscles are present in the ventricles of the heart. Chordae tendineae, the thread-like tendons of papillary muscles prevent the valves of the heart from movement by holding the flaps tightly against the strong flow of blood that is inserted upon the flaps of the tricuspid and bicuspid valve.