Cranial nerve, first: 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 first cranial nerve is the olfactory nerve which carries impulses for the sense of smell from the nose to the brain.
The word “olfactory” comes from the Latin “olfactare”, to sniff at and “olfacere”, to smell.
- Cranial nerve, fourth
Cranial nerve, fourth: 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, ninth
Cranial nerve, ninth: 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, second
Cranial nerve, second: The second cranial nerve 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 nerve, seventh
Cranial nerve, seventh: The seventh cranial nerve is the facial nerve, a mixed nerve that has fibers both going out and coming in (both efferent and afferent fibers). It supplies the muscles of facial expression. Paralysis of the facial nerve causes a characteristic picture with drooping of one side of the face, inability to wrinkle […]
- Cranial nerve, tenth
Cranial nerve, tenth: The tenth cranial nerve, and one of the most important, is the vagus nerve. All twelve of the cranial nerves, the vagus nerve included, emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. The vagus nerve originates in the medulla oblongata, […]