Question

Select the correct statement from the following.

• A. Valves guard the openings in the septum through which the atrium and ventricle are interconnected.
• B. Inter-atrial septum and inter-ventricular septum are thick partitions while atrio-ventricular partitions are thin.
• C. Mitral valve has two fibrous non-muscular cusps.
• D. All of the above.

Answer 1

Answer: (A)

Human heart:
Location: In the thoracic cavity in between the two lungs and slightly tilted to the left.
Size: Size of a clenched fist.
The heart is covered by a protective double membranous bag: pericardium. It has pericardial fluid in between.
The heart has 4 chambers: 2 atria (small upper chambers) + 2 ventricles (larger lower chambers).
Inter-atrial septum: It is a thin, muscular wall separating the right and the left atria.
Inter-ventricular septum: It is a thick, muscular wall separating the left and the right ventricles.
Atrio-ventricular septum: It is a thick fibrous tissue separating the atrium and the ventricle of the same side. These are having an opening within through which the two chambers of the same side are interconnected. Such openings are guarded by valves (atrioventricular valves):
I. Tricuspid valve or TV (made up of 3 muscular flaps or cusps): between the right atrium and the right ventricle.
II. Bicuspid valve or Mitral valve or MV (made up of 2 muscular flaps or cusps): between the left atrium and the left ventricle.