cranial nerve Flashcards
function of CN1
special sensory (or visceral afferent - smell)In addition to enable us to smell, CI also induces visceral responses via the ANS • For example, salivation is initiated in response to the aroma of food
function of optic nerve
special sensory (somatic afferent - vision)
formation of optic nerve
The optic nerve is formed by retinal ganglion axons that
converge at the optic disc at the back of the eye
why is optic nerve unique?
CII is unique in that it is surrounded by cranial meninges and subarachnoid space is filled with CSF
pathway of optic nerve
From the optic chiasma, it runs toward the brain (thalamus) by way of the optic tractsIn the brain some fibers terminate in the thalamus, others in the superior colliculi (corpora quadrigeminis) before travelling to the occipital lobe - visual cortex
which nerve is the chief motor nerve to the ocular and extra ocular muscle
occulomotor
which muscle is innervate by C111
- Superior, Inferior and Medial Rectus muscles
- Inferior Oblique muscle
- Levator Palpabrae muscle - Upper eyelid muscle
- Ciliary bodies (muscles) of the Lens
- Iris - is smooth muscle that acts like a sphincter to constrict and dilate the pupil size
- Reflex Somatic Adjustment - Proprioceptor
what is carrie by the inferior division of occulosmotor nerve
presynaptic autonomic fibers to the CILIARY GANGLION
where does the occulomotr divides
Within the superior orbital fissure, the nerve divides into the
superior and inferior divisions
cIV function
motor
pathway of trochlear Neve
Originates from the superiolateral aspect of the pons
• The trochlear nerve passes through the Superior Orbital Fissure
what happen if we injured the trochlear nerves
Injury to this nerve inhibits the eyeball form turning out and down (inferolaterally)
• DIPLOPIA (double vision).
which cranial nerve is the only one to emerge dorsally from the brainstem
trochlear
location of trigeminal nerve
side of pons
which division of CV Is purely sensory
CV1 et CV2
pathway and innervation of ophthalmic nerve
sensory nerve that passes through the Superior orbital fissure and supplies the eyeball, conjunctiva, lacrimal gland and sac, nasal mucosa, frontal sinus, external nose, upper eyelid, forehead and scalp.
pathway + innervation of maxillary nerve
a sensory nerve that passes through the Foramen Rotundum. It relays sensation from the skin of the face over the maxilla inluding the upper lip, maxillary teeth, nasal mucosa, maxillary sinuses and palate.
the 3rd division of CV is motor and sensory ?
yes
where does mandibular nerve pass
MANDIBULAR division (CV3) passes through the foramen OVALE and is both a sensory and a motor nerve.
innervation of mandibular nerve
Motor component: MUSCLES OF MASTICATION
Sensory component: skin over the mandible, lower lip and side of head, mandibular teeth, mucosa of the mouth and the ant two thirds of the tongue
pathway of abducens
The abducens nerve arises between the pons and the medulla on the brain and will travel through the SUPERIOR ORBITAL FISSURE to innervate the lateral rectus muscle
abducens is motor or sensory
motor
facial nerve is sensory or motor
both
pathway of CVII
- CVII emerges btw the pons and medulla on the brain and exits the skull though the internal acoustic meatus, facial canal and finally the STYLOMASTOID FORAMEN
- Passes through the parotid gland
which cranial nerve passes through the parotid gland
facial
innervation of facial nerve
Supplies: muscles of facial expression, taste to ant. two thirds of the tongue, parasympathetic innervation to the submandibular, sublingual and lacrimal glands and mucous glands of the soft palate, nose and paranasal sinuses.
location of vestibulochloar nerve
Located in the Petrous portion of the Temporal bone at the internal auditory meatus
Found just below the Pons the junction of the Medulla Oblongata
pathway of CVIII
The vestibulocochlear nerve enters the internal acoustic meatus where it then divides into vestibular (equilibrium) and cochlear (hearing) divisions
glossopharyngial is sensory or motor
both
which nerve is responsible for conveying taste from posterior third of tongue
CIX
innervation of CIX
Supplies sensory innervation to the pharyngeal mucosa, palatine tonsil, posterior one third of the tongue, auditory tube, middle ear, carotid sinus and carotid body
which muscle is only innervated by the glossopharyngieal nerve
stylopharygeus
which nerve supplies parasympathetic innervation to the parotid and salivary gland
CIX
sensory function of CIX
Sensory function (proprioception of swallowing muscles, monitoring BP, O2, CO2 in bld, breathing rate and depth)
pathway of CIX
Passes through the jugular foramen to exit the skull
which nerve name means the wanderer
vagus nerve
why vagus nerve means the wanderer
due to its extensive innervation throughout the body
function of vagus nerve
Responsible for sensation from the inferior pharynx, larynx and thoracic and abdominal viscera
• Taste from the root of the tongue and taste buds located on the epiglottis are also carried by CX
innervation of vagus nerve
Innervates the muscles of the soft palate, pharynx, the intrinsic laryngeal muscles and the palatoglossus muscles of the tongueParasympathetic innervation of the thoracic and abdominal viscera down to the splenic flexure
• Autonomic regulation of heart rate, respiration, digestion, blood pressure, etc.
which nerve is responsible forParasympathetic innervation of the thoracic and abdominal viscera down to the splenic flexure
• Autonomic regulation of heart rate, respiration, digestion, blood pressure, etc.
vagus
pathway of vagus
Exits the skull at the medulla oblongata with the glossopharyngeal nerve (C IX) at the Jugular Foramen
motor pathways of vagus nerve
- skeletal muscle - swallowing muscles of pharynx and larynx
- Smooth muscle
- Cardiac muscle
origin of accessory nerve
Originates from the medulla oblongata and spinal cord
pathway of accessory nerve
- The spinal portion enters the skull through the foramen magnum, joins the medullary portion and exits through the jugular foramen
- CXI also leaves the skull at the jugular foramen and is responsible for the motor innervation of the sternocleidomastoid and trapezius muscles
which muscle is innerve by accessory nerve
trap and SCM
pathway of hypoglossal nerve
The hypoglossal nerve arises from the medulla and leaves the skull from the medulla oblongata, through the hypoglossal canal
which nerve Joined temporarily by fibers from spinal nerves C1 and C2, which form the superior limb of the ansa cervicalis
CXII
innervation of CXII
CXII supplies motor innervation to all the muscles of the tongue except palatoglossus (supplied by the Vagus nerve - CX)
