Question

The heart is a hollow muscular cone-shaped organ lying between the lungs in the thoracic cavity. In the given diagram of heart certain parts have been labelled as a, b, c, d and e. Select the correct option.

A)The part labelled C closes shortly after the start of ventricular systole while D closes shortly after diastole starts.
B)The parts labelled C and D have three and two flaps respectively.
C)The part labelled B carries impure blood.
D)The part labelled A carries pure blood while E carries impure blood.

Answer 1

Hint: The heart is the main blood pumping organ in our body. It receives impure or deoxygenated blood from all the parts of the body through veins and sends it to lungs for oxygenation. The lungs send the pure blood back to the heart. The heart then pumps the pure blood to all parts of the body through arteries.

Complete answer:
The heart is divided into four parts: the upper two chambers are the right and left ventricle.
The bottom two are the right and left ventricle. The right auricle receives deoxygenated blood from all the parts of the body.

The parts labelled in the figure are as follows:
A)Pulmonary Artery: It is the only artery which carries deoxygenated (impure) blood from the right ventricle to the lungs for oxygenation. Option D is incorrect.

B)Pulmonary vein- It is the vein which brings back oxygenated(pure) blood from lungs to heart (left auricle). Thus, option C is incorrect.

C)Tricuspid valve- This valve is present in between the right auricle and ventricle. It prevents the backflow of blood and also regulates the flow of blood. It is made up of three cusps. It closes shortly after the start of ventricular diastole.

D)Bicuspid valve- This valve is present in between the left auricle and ventricle. It prevents the backflow of blood and also regulates the flow of blood. It is made up of two cusps. It closes shortly after the ventricular systole.

E)Vena cava- This is a vein which brings blood (impure) from all the parts of the body to heart.

Hence, the correct answer is option (B)

Note: Systole and diastole are the two phases of the cardiac cycle. Systole occurs when the heart contracts to pump out blood. Diastole occurs when the heart relaxes after contraction. They are the important component of blood pressure.