Question

Number of spinal nerves in frog is
A) Ten only
B) Ten pairs
C) Twelve pairs
D) Twenty pairs

Answer 1

Hint:Organs of the nervous system control and coordinate all the activities of the body. Nervous system mainly consists of two parts: the central nervous system and the peripheral nervous system. Central nervous system has the brain and spinal cord on the other hand the peripheral system consists of various nerves which serve the purpose of connecting central nerves with body parts.

Complete answer:
>Peripheral nerves system further divided into two nerves: Cranial nerves and Spinal nerves.
Cranial Nervous: These Nerves start from the brain are called cranial nerves. Ten pairs of cranial nerves are present in the frog.
Spinal Nerves: These Nerves start from the spinal cord are called spinal nerves and nine or ten pairs of spinal nerves. Spinal nerves are of the following types: Sensory nerves, motor nerves and mixed motors.
Sensory Nerves: carry messages from sensory organs to the central nervous system.
Motor Nerves: Carry messages from the central nervous system to glands and muscles.
Mixed Nerves: These nerves having the quality of both nerves (sensory and motor nerves)

Hence, the correct answer is option ‘A’ Ten pairs.

Note:Spinal nerves are mixed nerves on the other hand cranial nerves are of all three types.Color of spinal nerves of frog is white in color and is thread-like structures that appear between the vertebrae and are present along the dorsal wall of body cavity.