Question

Foramen of Panizza is associated with
A) Brain of reptiles.
B) Brain of a rabbit.
C) Lung of lizard.
D) Heart of crocodile.

Answer 1

Hint: The foramen of Panizza has a variable calibre. This is associated with the semi aquatic reptiles that live in Africa, Asia. They belong to the phylum Chordata and class reptilia.

Complete Answer:
- The heart of the crocodile is very much different from the other reptiles because in all the other reptiles oxygenated blood mixes with the deoxygenated blood in the ventricles. This is because the ventricles are divided from each other partially.
- But on the other hand, both atria and both the ventricles are separated completely. So, there is a connection which exists between arterial and venous circulation by the way of foramen of Panizza.
- It opens between the two vessels leading separately from the both ventricles and this connection comes into action when the crocodile holds its breath. Due to which it allows the blood to bypass the lungs when the animal is submerged. This stabilizes the blood oxygen levels.
- The foramen have a variable calibre which explain the changes in the distribution of pressure flow and profiles.

Thus, the correct answer is option D i.e., Heart of crocodile.

Note:
- Some of the species of the crocodilians have sphincters that are regulated which prevent unwanted blood flow with the help of foramen of Panizza during non-diving.
- Deoxygenated blood flow into the atria with the help of the foramen of Panizza. This deoxygenated blood releases from the right ventricles. Both the ventricles and atria are separated in the crocodiles.