Cranial bone: Part of the top portion of the skull which protects the brain. The bones of the cranium include the frontal, parietal, occipital, temporal, sphenoid, and ethmoid bones.
- Cranial nerve II
Cranial nerve II: The second cranial is the optic nerve, the nerve that connects the eye to the brain and carries the impulses formed by the retina — the nerve layer that lines the back of the eye, senses light and creates the impulses — to the brain which interprets them as images. The cranial […]
- Cranial nerve I
Cranial nerve I: The first nerve to emerge from or enter the skull (the cranium). (There are twelve cranial nerves.) The first cranial nerve is the olfactory nerve which permits the sense of smell. See: Olfactory nerve.
- Cranial nerve III
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 […]
- 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). […]