Question

Heart of fish receive
a. Oxygenated blood
b. Deoxygenated blood
c. Both A and B
d. None of the above

Answer 1

Hint: In fish, the heart consists of two chambers, mainly the atrium and ventricle, where the blood is oxygenated in the gills of the fish and carried to body parts and the sinus venosus and all finally enters to the heart chambers.

Complete answer:
- Fish mainly consists of a two-chambered heart, which means it contains mainly two pumping chambers.
- The two chambers are the atrium and ventricle
- Along with this, they also have sinus venous and bulbus arteriosus.
- Blood that normally returns from the body parts enters the sinus venosus
- Sinus venosus in the fish is commonly present as a small sac.
- It is a thin walled sac, where all the major veins of the fish coalesce.
- From the sinus venosus, the blood is pulled by the atrium by expansion.
- Where blood enters the atrium, atrium muscles are a little weak, then after the blood is entered into the ventricles, hereby strong muscular pumps.
- Because of the strong muscular pump, blood enters the bulbus arteriosus, and then it enters the ventral aorta
- From the aorta, the blood enters the gills
- In the heart of the fish, again there are three valves, which prevent the backward flow of the blood during diastole.
- The blood pressure in the fish is usually very low, especially in the case of ventricles, mainly the circulation is by the strong muscular contractions.

Hence, The correct answer is option (B).

Note: In some species of the fish, in order to maintain the pressure, there is the presence of accessory hearts, so in fish, purification of blood takes place in gills, while unpurified blood or deoxygenated blood is received by the heart.