What is the oculomotor nerve composed of?
The oculomotor nerve is composed of about 23 000 myelinated nerve fibers which extend from cell bodies in the midbrain to their target muscles in the orbit. A number of authors have described the portion of this nerve comprising autonomic fibers, some of which are pupillomotor axons.
What does Edinger-Westphal nucleus do?
The Edinger–Westphal nuclei provide preganglionic input to the ciliary ganglion mediating the pupillary light reflex and accommodation responses of the lens (i.e., the ciliary body).
Which of the following structures are found at the level of the oculomotor nerve nucleus in the midbrain?
The oculomotor nucleus is found at the level of the superior colliculus. It contains the somatic efferent fibers that control the medial rectus, inferior rectus, superior rectus, inferior oblique, and the striated muscle in the levator palpebrae superioris. The oculomotor nucleus is split up into multiple subnuclei.
Why is the oculomotor nerve unique?
The oculomotor nerve has two distinct functions, the somatic motor that supplies four of the six extraocular muscles of the eye and the levator palpabrae superioris muscle of the upper eyelid. The visceral motor function provides parasympathetic innervations to the constrictor pupillae and ciliary muscles.
Where is superior Salivatory nucleus?
the pons
Neuroanatomy of the Autonomic Nervous System The cell bodies of these fibers are located in the superior salivatory nucleus. This nucleus is located in the caudal part of the pons near the facial motor nucleus.
What is the general visceral motor nucleus of the oculomotor nerve?
Cranial nerve nuclei
| General somatic efferent nuclei | Oculomotor, trochlear, abducens, hypoglossal |
|---|---|
| General visceral efferent nuclei | Accessory oculomotor nucleus (Edinger-Westphal nucleus), salivatory nuclei, dorsal vagal nucleus |
Which of the following structure are found at the level of the oculomotor nerve nucleus in the midbrain?
The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle….
| Oculomotor nucleus | |
|---|---|
| FMA | 54510 |
| Anatomical terms of neuroanatomy |
Is the oculomotor nerve sensory or motor?
Somatic Motor
| Nerves in Order | Modality | Function |
|---|---|---|
| Olfactory | Special Sensory | Smell |
| Optic | Special Sensory | Vision |
| Oculomotor | Somatic Motor Visceral Motor | Levator palpebrae, superioris, superior, medial & inferior recti muscles Parasympathetic to ciliary & pupillary constrictor muscles |
| Trochlear | Somatic Motor | Superior oblique muscle |
Which cranial nerves belong to the solitary tract nucleus?
The solitary tract nucleus receives afferent fibers from the glossopharyngeal and vagus (9th and 10th cranial) nerves, which carry afferent input from baroreceptors and chemoreceptors of the thoracic and abdominal viscera.
What is pretectal nucleus?
The pretectum is a bilateral group of highly interconnected nuclei located near the junction of the midbrain and forebrain. The pretectum is generally classified as a midbrain structure, although because of its proximity to the forebrain it is sometimes classified as part of the caudal diencephalon (forebrain).
What is Edinger?
The Edinger–Westphal nucleus (accessory oculomotor nucleus) is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.
Where is inferior salivatory nucleus?
The inferior salivatory nucleus is a small nucleus in the upper medulla that innervates the otic ganglion with GVE fibers of the glossopharyngeal nerve. The otic ganglion provides parasympathetic innervation to the parotid gland.
Where are the nucleus of cranial nerves?
The cranial nerve nuclei are horizontal structures spread out in the midbrain (III, IV), the pons (V, VI, VII, VIII), and the medulla (IX, X, XI, XII).
What is the function of oculomotor nucleus?
The oculomotor nerve is the third cranial nerve (CN III). It allows movement of the eye muscles, constriction of the pupil, focusing the eyes and the position of the upper eyelid.
What is the oculomotor nucleus?
Oculomotor nucleus. The nucleus of the oculomotor nerve does not consist of a continuous column of cells, but is broken up into a number of smaller nuclei, which are arranged in two groups, anterior and posterior. Those of the posterior group are six in number, five of which are symmetrical on the two sides of the middle line,…
Where is the oculomotor nerve located?
(Oculomotor is “III”) The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle.
Which subnucleus of the oculomotor nucleus is responsible for parasympathetic innervation?
The subnucleus of the oculomotor nucleus that is responsible for parasympathetic innervation to the eye is the Edinger–Westphal nucleus. Its fibers travel with the oculomotor nerve as the long ciliary nerves.