Question

Number of spinal nerves in frog is
A) 8 pairs
B) 10 pairs
C) 11 pairs
D) 12 pairs

Answer 1

Hint: Frogs have a little bit complex nervous system which comprises the cranial and spinal nerves. The spinal nerves that are present will branch out to the different organs in the frog’s body sending signals to the brain.

Complete answer:
The nervous system controls all the voluntary and involuntary activities of the body such as smell, hearing, sight and movement. Though frogs are small carnivorous amphibians their nervous system is well developed with a brain analogous to that of humans. They have 10 pairs of cranial nerves whose primary function is to obtain information from the outside environment to the brain. Similarly, there are 10 pairs of spinal nerves which brings information from the organs in the body to the brain through the spinal cord.

Hence, the correct answer is option (B). Frogs have 10 pairs of spinal nerves.

Additional information:
The Bell – Magendie law was framed by scientists Sir Charles Bell and physiologist François Magendie. Their findings, performed 11 years apart, concluded that the motor fibers were controlled by anterior spinal nerves and the sensory fibers by posterior spinal nerve. A similar finding was reproduced by Johannes Peter Müller in his experiment called Müller’s frog experiment. He used frogs for his study as their spinal cord and the nerves associated with it are simple and easier to remove. Though his work was not credited by the law, his choice of animal as frog has been useful in teaching and experiments involving neurophysiology.

Note: The tadpoles of frogs have more than 40 pairs of spinal nerves. But after degeneration of their tail, they are left with only 10 pairs of spinal nerves which are found in the anterior end.