Cranial nerve III: The third cranial nerve is the oculomotor nerve. The cranial nerves emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. There are twelve cranial nerves.
The oculomotor nerve is responsible for the nerve supply to muscles about the eye:
The upper eyelid muscle which raises the eyelid;
The extraocular muscle which moves the eye inward; and
The pupillary muscle which constricts the pupil.
Paralysis of the oculomotor nerve results in drooping eyelid (ptosis), deviation of the eyeball outward (and therefore double vision) and a dilated (wide-open) pupil.
- Cranial nerve IV
Cranial nerve IV: The fourth cranial nerve, the trochlear nerve, is the nerve supply to the superior oblique muscle of the eye, one of the muscles that moves the eye. Paralysis of the trochlear nerve results in rotation of the eyeball upward and outward (and, therefore, double vision). The twelve cranial nerves, the trochlear nerve […]
- Cranial nerve IX
Cranial nerve IX: The ninth cranial nerve is the glossopharyngeal nerve. The 12 cranial nerves, the glossopharyngeal nerve included, emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. The glossopharyngeal nerve supplies the tongue, throat, and one of the salivary glands (the parotid gland). […]
- Cranial nerve V
Cranial nerve V: The fifth cranial nerve is the trigeminal nerve. The trigeminal nerve is quite complex. It functions both as the chief nerve of sensation for the face and the motor nerve controlling the muscles of mastication (chewing). Problems with the sensory part of the trigeminal nerve result in pain or loss of sensation […]
- Cranial nerve VI
Cranial nerve VI: The sixth cranial nerve is the abducens nerve. It is a small motor nerve that has one task: to supply a muscle called the lateral rectus muscle that moves the eye outward. Paralysis of the abducens nerve causes inward turning of the eye (internal strabismus) leading to double vision. The cranial nerves, […]
- Cranial nerve VII
Cranial nerve VII: The cranial nerves emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. There are twelve cranial nerves. The facial nerve is the seventh cranial nerve. The facial nerve supplies the muscles of facial expression. Paralysis of the facial nerve causes a […]