Question

Enlist the number and names of motor cranial nerves in a human being?

Answer 1

Hint: Cranial nerves in a human being emerge from the human brain. It has the role to pass information between the effector (parts of the body) to the receptor (brain). The cranial nerves originate from above the level of the first vertebrae of the vertebral column in the central nervous system. Motor cranial nerves function in the movements of the head and neck.

Complete answer:
There are a total of 5 motor nerves in a human being. The names of motor nerves are Oculomotor (III), Trochlear (IV), Abducens (VI), Accessory spinal (XI), and Hypoglossal (XII) each of them being paired. Human beings possess a total of 12 pairs of cranial nerves. Classes of Phylum Chordata like reptilia, amphibia have 10 pairs of cranial nerves whereas class Mammalia has 12 pairs of cranial nerves.

Additional Information: - The point of origin and termination of cranial nerves is the brain and for spinal nerves is the spinal cord.
- Cranial nerves are involved in activities of the head and neck and spinal nerves are involved in activities of parts of the body below the neck.
- Sensory nerves take impulse from affected organs to the central nervous system and motor nerves take impulse from the central nervous system to the receptor.
-Cranial nerves in members of class Mammalia are 12 pairs and the number of spinal nerves is 31 pairs. Cranial nerves are of three types- sensory (3 pairs), motor (5 pairs), and mixed (4 pairs). All spinal nerves are of mixed type.
So, the correct answer is `there are 5 pairs of cranial motor nerves in human being and their names are- Oculomotor(III), Trochlear(IV), Abducens(VI), Accessory spinal(XI), and Hypoglossal(XII)`.

Note: There are 31 pairs of spinal nerves- cervical (8 pairs), thoracic (12 pairs), lumbar (5 pairs), sacral (5 pairs), and coccygeal (1 pair). These are all mixed nerves and control the impulse system below the level of the neck in the body. The cranial nerves are- olfactory(I), optic(II), oculomotor(III), trochlear(IV), trigeminal(V), abducens(VI), facial(VII), auditory(VIII), glossopharyngeal(IX), vagus(X), accessory spinal(XI) and hypoglossal(XII). Out of these, I, II, and VIII are sensory, III, IV, VI, XI, XII are motor, and V, VII, IX, X are mixed nerves.