What does the trochlear nerve innervate?
What does the trochlear nerve innervate?
The trochlear nerve provides innervation to one skeletal muscle only, the superior oblique. The motor neurons that form the trochlear nerve are located in the trochlear nucleus, which is located at the caudal end of the oculomotor nucleus at the level of the inferior colliculus.
Where does the trochlear nerve innervate?
superior oblique muscle
The only muscle the trochlear nerve innervates, the superior oblique muscle, is the longest and thinnest muscle among the extraocular muscles. The muscle belly originates from the back of the roof of the orbit near the common tendinous ring, but it takes an unusual course to reach the eye.
What is the smallest nerve in the body?
Trochlear nerve
It is the smallest nerve in terms of the number of axons it contains. It has the greatest intracranial length. It is the only cranial nerve that exits from the dorsal (rear) aspect of the brainstem….
| Trochlear nerve | |
|---|---|
| Innervates | Superior oblique muscle |
| Identifiers | |
| Latin | nervus trochlearis |
| MeSH | D014321 |
How do you test for the 12th cranial nerve?
The 12th (hypoglossal) cranial nerve is evaluated by asking the patient to extend the tongue and inspecting it for atrophy, fasciculations, and weakness (deviation is toward the side of a lesion).
Where does the oculomotor nerve originate in the body?
The oculomotor nerve originates from the third nerve nucleus at the level of the superior colliculus in the midbrain.
What are the symptoms of an oculomotor nerve lesion?
Oculomotor nerve lesion symptoms associated with visceral motor dysfunction accompanied by head pain would be indicative of an aneurysm. Painless dysfunction of the somatic motor functions of the nerve however, would be indicative of vascular ischemic disease, perhaps as a complication of diabetes.
Is there paralysis of the oculomotor ( III ) nerve?
There is paralysis of the muscles innervated by the III nerve (with or without pain), with (or without) combined IV, VI nerves (ophthalmoplegia) and I of the V branch of the nerve with Horner’s syndrome on the same side.
What happens to muscles innervated by the III nerve?
There is paralysis of the muscles innervated by the III nerve with or without IV, VI and the first branch of the V nerves, often exophthalmos. There is paralysis of the muscles innervated by the III nerve. If the optic nerve is involved, visual acuity decreases. Possible exophthalmos, chemosis.