The trochlear nerve is the fourth cranial nerve (CN IV) and one of the ocular motor nerves that controls eye movement. The trochlear nerve, while the smallest of the cranial nerves, has the longest intracranial course as it is the only nerve to have a dorsal exit from the brainstem.
Which is the shortest cranial nerve?
The trochlear nerve is the fourth paired cranial nerve. It is the smallest cranial nerve (by number of axons), yet has the longest intracranial course.
What is the smallest nerve?
The trochlear nerve is unique among the cranial nerves in several respects: It is the smallest nerve in terms of the number of axons it contains. It has the greatest intracranial length.
Which is the longest cranial nerve?
The vagus nerve (cranial nerve [CN] X) is the longest cranial nerve in the body, containing both motor and sensory functions in both the afferent and efferent regards.
Which is the 1st cranial nerve?
The olfactory nerve (CN I) is the first and shortest cranial nerve. It is a special visceral afferent nerve, which transmits information relating to smell.
Which is the thickest cranial nerve?
The largest cranial nerve is trigeminal nerve. The smallest cranial nerve is abducens nerve. The thinnest cranial nerve is trochlear nerve.
How do you test cranial nerve 4?
Trochlear nerve (CN IV)
Cranial nerve IV acts as a pulley to move the eyes down—toward the tip of the nose. To assess the trochlear nerve, instruct the patient to follow your finger while you move it down toward his nose.
Which is largest nerve in human body?
The sciatic nerve is the largest nerve in your body. It begins in your lower back and travels all the way down to the heel of your foot. You may have heard of a condition called sciatica in which painful sensations radiate from your lower back and down your leg.
What happens if the trigeminal nerve is damaged?
Trigeminal nerve injuries not only causes significant neurosensory deficits and facial pain, but can cause significant comorbidities due to changes in eating habits from muscular denervation of masticator muscles or altered sensation of the oral mucosa.
Does Trochlear nerve cross?
The trochlear nucleus gives rise to nerves that cross (decussate) to the other side of the brainstem just prior to exiting the brainstem. Thus, each superior oblique muscle is supplied by nerve fibers from the trochlear nucleus of the opposite side.
Which side of the neck is the vagus nerve on?
On the right side, it arises from the trunk of the vagus as it lies beside the trachea. On the left side, it originates from the recurrent laryngeal nerve only.
How do you test for cranial nerve 10?
The motor division of CN 9 & 10 is tested by having the patient say “ah” or “kah”. The palate should rise symmetrically and there should be little nasal air escape. With unilateral weakness the uvula will deviate toward the normal side because that side of the palate is pulled up higher.
How do you test for cranial nerve 2?
2nd Cranial nerve
For the 2nd (optic) cranial nerve, visual acuity is tested using a Snellen chart for distance vision or a handheld chart for near vision; each eye is assessed individually, with the other eye covered.
What is the acronym for the 12 cranial nerves?
Here is a handy-dandy mnemonic for you: On Old Olympus Towering Top A Famous Vocal German Viewed Some Hops. The bold letters stand for: olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, spinal accessory, hypoglossal.
Which cranial nerve is responsible for smell?
The olfactory nerve carries impulses for the sense of smell. The optic nerve carries impulses for the sense of sight. The occulomotor nerve is responsible for motor enervation of upper eyelid muscle, extraocular muscle and pupillary muscle.