Question

In which of the followings cavity is the human heart situated?
1. Dorsal Cavity
2. Spinal Cavity
3. Thoracic Cavity
4. Ventral Cavity

Answer 1

Correct Answer - Option 3 : Thoracic Cavity

Option 3 is correct:

• The heart is situated in the thoracic cavity, in between the two lungs, slightly tilted to the left.
• It is protected by a double-walled membranous bag, pericardium, enclosing the pericardial fluid.
• The pericardium is a fibre membrane found as an external covering around the heart.
• Carrying deoxygenated blood away from the heart, to the lungs and then brings oxygenated blood back to the heart, this sequential event in the heart which is cyclically repeated is called the cardiac cycle. 
• And it consists of systole and diastole of both the atria and ventricles.
• The duration of the cardiac cycle is 0.8 second.
• Heart → Organ (Systole)
• Organ → Heart (Diastole)
• During each cardiac cycle, two prominent sounds are produced which can be easily heard through a stethoscope.
• The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves.
• Whereas the second heart sound (dub) is associated with the closure of the semilunar valves.