Inferior surface of the brain as it appears
• Inferior surface of the brain as it appears on gross dissection.
The Olfactory nerve (I) – for sense of smell. Nerves in nasal cavity synapse within olfactory bulbs. Anosmia – loss of smell. Sensory
The Optic nerve (II) - visual information. 50 -50 cross over Anopsias – visual defects. Sensory
6 Extrinsic Eye Muscles 4 Rectus Muscles 2 Oblique Muscles oblique rectus Nose here oblique
The Oculomotor nerve (III) - Controls 4 of the 6 extrinsic muscles of the eye. Motor External Strabismus – lateral drift. Ptosis. The Trochlear nerve (IV) – Innervates superior oblique eye muscle. Motor
• The Trigeminal nerve (V) Mixed Largest cranial nerve Has 3 Branches 1) Ophthalmic branch skin, lacrimal gland 2) Maxillary branch lower eyelid, upper jaw 3) Mandibular branch tongue, lower teeth e. g. , Tic Douloureux.
The Abducens nerve (VI) Motor Innervates lateral rectus muscle of eye (abduction!) Internal Strabismus – cross eyed. The Facial nerve (VII) Mixed Controls muscles of scalp and facial expression. Muscles of mastication and speech. Pressure sensations from face. Taste sensations from anterior 2/3 of tongue. e. g. , Bell’s palsy.
The Facial nerve (VII) Mixed
The Vestibulocochlear nerve (VIII) Sensory – Sense of balance, position and body movement. Loss of balance, nausea, vomiting. – Sense of sound (hearing). Deafness.
The Glossopharyngeal nerve (IX) Taste sensation from posterior 1/3 tongue. Controls swallowing Detects O 2 and CO 2 content of blood in carotid artery. Impairment of taste and swallowing. Mixed
The Vagus nerve (X) Mixed Controls vocal folds Hoarseness of voice. Regulates heart Impaired regulation of heart. Controls G. I. Tract Impaired G. I. tract motility. Vital to autonomic control of visceral function
The Accessory nerve (XI) Motor – Internal branch Innervates swallowing muscles. – External branch Controls sternocleidomastoid and trapezius. Turn toward injured side. Impaired shrugging. The Hypoglossal nerve (XII) Motor Voluntary food mixing, swallowing and speech. Control of tongue movements. Impaired swallowing. Deviating tongue (atrophy).
• The Accessory nerve (XI) and Hypoglossal nerve (XII)
- Slides: 16