As we know our brain functions on different nerves of our body. Different organs perform different types of functions like vision, smell, hearing and balance, movements, etc. and these works are controlled by different nerves controlled by our brain.
There are two types responsible for body function i.e. CRANIAL NERVES and SPINAL NERVES.
These nerves are responsible for relaying information between the brain and the body parts, primarily to the regions of head and neck and sensory organs that are responsible for special senses like vision, hearing, taste, smell, etc. Some of these nerves bring information from the sense organs to the brain called SENSORY NERVES. Some cranial nerves control muscles are called MOTOR NERVES. Other cranial nerves control internal organs and glands like heart, lungs, etc. are called MIXED NERVES.
There are 12 Pairs of Cranial Nerves
- Olfactory nerves- (sensory)- sense for smell
- Optic nerves (sensory)- sense for vision
- Oculomotor nerves (motor)- muscle function and pupil response
- Trochlear nerves (motor)- eye movement (sup. Oblique muscle)
- Trigeminal nerves (mixed)- touch, pain, jaw, face, head
- Abducens nerves (motor)- eye movement (lat. Rectus muscle)
- Facial nerves (mixed)- muscle control for facial expression, sense for taste
- vestibulo-cochlear nerves (sensory)- hearing and balance
- Glossopharyngeal nerves (mixed)- sense for taste
- Vagus nerves (mixed)- swallowing of food
- Accessory nerves (motor)- muscle of neck and shoulder to flex and extend
- Hypoglossal nerves (motor)- movement of tongue
Mnemonics to Learn Cranial Nerves
Tricks to Learn Functions of Cranial Nerves
A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body.
There are 31 pairs of spinal nerves responsible for relay information which arise from the spinal cord.
Each spinal nerve is formed by the combination of nerve fibers from the dorsal and ventral roots of the spinal cord. The spinal nerves act as “telephone lines,”
There are 8 cervical nerves , 12 thoracic nerves, 5 lumbar nerves, 5 sacral nerves and 1 coccygeal nerves.