Cranial nerves Flashcards
What is the origin, course and function of CNI?
The olfactory nerve takes sensory info from the nose, through the cribiform plate to form the olfactory bulb then the olfactory tract. It leads to the allocortex.
It joins part of the limbic system to bring emotion into scent.
What is the origin, course and function of CNII?
The optic nerve starts at the eye, passes through the optic canal and then half of the fibers cross over to the other side to form the optic chiasma. This forms the optic tract, which takes sensory info to the lateral geniculate nucleus and then to the visual cortex.
What is the origin, course and function of CNIII?
The occulomotor nerve passes motor information from the midbrain, through the superior orbital fissure and to the eye. It innervates superior, inferior and medial rectus and inferior oblique. Occulomotor also innervates constrictor pupilae and levator palpabrae superioris.
What is the origin of, course and function of CNIV?
The trochlear nerve passes from the pons through the superior optical fissure to the eye to supply motor control of superior oblique.
What is the origin of, course and function of CNV?
The trigeminal nerve initiates from the pons and breaks into three different neurons before exiting the skull. The three neurons are the opthalamic, maxillary and the mandibular nerves.
The opthalamic division (V1) leaves the skull through the superior orbital fissure. It carries sensory information from the forehead, upper nose, eyelids, cornea, lacrimal gland.
The maxillary division (V2) exits through the foramen rotundum and receives sensory input from lower eye, upper lip and cheek. Also glands and structures within the nose and mouth.
The mandibular nerve (V3) exits through the foramen ovulae and receives sensory input from the anterior 2/3 of the tongue, salivary glands in mouth, regulation of the parotid gland. Motor function of the muscles involved in the jaw.
What is the origin of, course and function of CNVI?
The abducens nerve travels from the pons, through the superior orbital fissure to the eye to supply motor control to lateral rectus.
What is the origin of, course and function of CNVII?
The facial nerve goes through the internal acoustic meatus and controls the muscles of the face for expression, gives off multiple nerves to innervate the different muscles, oral, zygomatic, buccal, mandibular and cervical. Gives off the chorda tympani, which recieves taste from the anterior tongue. Control of tear ducts, controls the stapedius muscle, controls saliva prduction from the sumandibular glands. Control of eyelid (corneal reflex).
What is the origin of, course and function of CNVIII?
The vestibulocochlear nerve receives sensory info from the cochlear and the vestibular systems and then travels through the internal acoustic meatus to the medulla. Balance and hearing.
What is the origin of, course and function of CNIX?
The glossopharangeal nerve receiving information from the tongue and throat. It passes through the jugular foramen. It then forms the tympanic nerve which gets sensory info from the inner ear. Carries parasympattic fibers to control the parotid gland to produce saliva. Sensory info from the carotid sinus, which senses changes in pH and O2/CO2. Innervates the carotid body, which senses pressure in the carotid.
Muscles in swallowing, sensory info from soft pallet and the pharynx. Taste and sensation from the posterior tongue.
What is the origin of, course and function of CNX?
The vargus projects past the neck into the body. Gives out branches that control the sensory from the exterior part of the inner ear. Info from meninges. Then it passes through the jugular foramen. Receives sensory info from the larynx. Recurrent laryngeal nerve. Heart, blood pressure, pulmonary plexus (lungs), eosophegeal plexus, liver, kidneys, spleen, small intestine parasympathetic.
What is the origin of, course and function of CNXI?
The accessory nerve also goes through the jugular foramen and it controls trapezius and the sternocleidomastoid muscle. Involved in shrugging etc.
What is the origin of, course and function of CNXII?
The hypoglossal nerve goes through the hypoglossal foramen. Motor control of the tongue.
