Trigeminal nerve is a mixed nerve. It is the largest of the cranial nerves. It is connected to the lateral aspect of the pons by a large sensory root and a small motor root; the sensory root forms the semilunar ganglion under which the motor root passes forward. The convex face of the ganglion gives […]
Trochlear nerve is the motor nerve to the superior oblique muscle of the eyeball. It is the finest of the cranial nerves. It arises from the dorsal aspect of midbrain close to and behind the corpora quadrigemina where the anterior cerebellar peduncle enters the midbrain. The nerve passes forward and outward along the lateral border of
Occulomotor nerve is the motor nerve to the muscles of the eyeball. It arises from the ventromedial aspect of the cerebral peduncle turns sharply outward and forward, crossing over the posterior primary branch of the emergent artery of the rete mirabile cerebri through the cavernous sinus along with the ophthalmic and the sixth cranial nerves.
Optic nerve is a nerve of sense for sight. This nerve is composed of medullated fibres devoid of neurilemma which are axons of the ganglion cells of retina. The fibres converge within the eyeball at the optic papilla, where they form the optic nerve. Then it pierces through the choroid and sclera, emerges from the
Olfactory nerve is a nerve of special sense for smell. It consists of fibers which are the axons of the olfactory cells in the olfactory part of the nasal mucous membrane. The fibres are non-medullated and are collected into small bundles enclosed in sheaths furnished by the meninges of the brain; pass through the cribriform
No. Name Kind Origin 1. Olfactory nerve Nerve of special sense (smell) Fore Brain 2. Optic nerve Nerve of special sense (sight) Fore Brain 3. Oculo Motor Nerve Motor nerve Fore Brain 4. Trochlear Nerve Motor Nerve Fore Brain 5. Trigeminal Nerve Mixed nerve Mid Brain 6. Abducent Nerve Motor nerve Mid Brain 7. Facial
There are twelve pairs of cranial nerves in animals- The first pair or olfactory nerve joins the convex ventral face of the olfactory bulbs. The second pair or optic nerve arises from the lateral geniculate bodies; the optic tracts converge to the optic chiasma and are then continued as optic nerves. The third pair or
Ascending tract Ventral spino -thalamic tract: This ascending tract consists of fibres derived from the sensory neurons of dorsal gray column, which ascend directly upto two or three segments and then cross to the opposite side to reach the ventral white column. They pass up to the thalamus, from where they are relayed to the sensory
Ascending tracts Lateral spino thalamic tract: It lies medial to the preceding. The fibres arise from the dorsal horn of the opposite side cross the median plane and ascend through the medulla. It ascends as the spinal lemniscus and reaches the ventral portion of the lateral nucleus of the thalamus from where they are relayed
Fasciculus gracilis Comma tract Fasciculus cuneatus. The first two are ascending tracts conveying the same types of sensations. Fasciculus gracilis conveying impulses from the posterior parts of the body (posterior thoracic, lumbar, sacral and coccygeal) and the Fasciculus cuneatus conveying impulses from the anterior half (anterior cervical and thoracic). Both are in the dorsal white
