cranial nerves

Vestibulocochlear Nerve

Vestibulocochlear Nerve The structure indicated is the vestibulocochlear nerve (cranial nerve VIII). The vestibulocochlear nerve consists of a vestibular branch and a cochlear branch. The vestibular branch is responsible for balance, and the cochlear branch is responsible for hearing. It originates laterally in the cerebellopontine angle and passes together with the facial nerve into the internal acoustic meatus of the temporal bone.   Cochlear nerve Bipolar sensory neurons in the organ of coorti pass impulses from the hair cells of the cochlear via the peripheral axonal process to the spiral ganglia (this is the collection of cell bodies of the …

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vestibulocochlear nerve

Optic Nerve

Optic Nerve The structure indicated is the optic nerve (cranial nerve II). The optic nerve is the second cranial nerve and is responsible for vision. Similar to the first cranial nerve (olfactory nerve), the optic nerve is not a true nerve but is rather an extension of the brain (diencephalon), which means it is technically a part of the central, rather than peripheral nervous system. The primary sensory neurons are the bipolar cells of the retina; these synapse on ganglion cells, the axons of which form the optic nerve which then passes via the optic canal to join with the …

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optic nerve

Facial Nerve

Facial Nerve The structure indicated is the facial nerve (cranial nerve VII). The facial nerve is responsible for supplying the muscles of facial expression. In addition, the facial nerve provides taste sensation to the anterior 2/3 of the tongue and secretomotor function to the salivary, lacrimal, nasal and palatine glands. The facial nerve originates from the cerebellopontine angle, laterally at the junction between the pons and the medulla. It has two roots: a motor root and the nervus intermedius, which carries the parasympathetic and sensory fibres. Intracranial branches Greater petrosal nerve Nerve to stapedius Chorda tympani Extracranial branches Posterior auricular …

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facial nerve

Hypoglossal Nerve

Hypoglossal Nerve The structure indicated is the hypoglossal nerve (cranial nerve XII). The hypoglossal nerve carries general somatic efferent nerve fibres and is responsible for motor innervation to the extrinsic and intrinsic muscles of the tongue. It arises from the hypoglossal nucleus located in the caudal brain stem and emerges from the preolivary sulcus in the ventromedial aspect of the medulla oblongata from several rootlets. The preolivary sulcus separates the olive from the medullary pyramids. The hypoglossal nerve then passes through the subarachnoid space and exits the skull through the hypoglossal canal. The extrinsic muscles of the tongue are as …

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Hypoglossal Nerve

Abducent Nerve

Abducent Nerve The structure indicated is the abducent nerve (cranial nerve VI). The abducent nerve (cranial nerve VI), provides general somatic efferent fibres (motor function) to the lateral rectus muscle of the eye. There are three cranial nerves which are responsible for innervating the extrinsic muscles of the eye: Oculomotor nerve (cranial nerve III) Trochlear nerve (cranial nerve VI) Abducent nerve The oculomotor nerve supplies the superior, inferior and medial rectus muscles, as well as the inferior oblique muscle and the levator palpebrae superioris. The trochlear nerve supplies the superior oblique muscle. It originates between the pons and the medulla …

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Abducent nerve