Week 7- cranial nerves Flashcards
Arises from the olfactory epithelium
filaments pass through the cribriform plate of the ethmoid bone
shortest of the cranial nerves
Olfactory nerve (cranial nerve I)
Loss of function=
anosmia= lack of olfaction or less os steel
Hyposmia= decreases
Olfactory nerve (cranial nerve I)
Starts at retina
Optic nerve pass through the optic canals and converge at the optic chiasm
Continues to thalamus as optic tracts where they synapse
Optic radiation fibers run to the visual cortex
Retina, optic nerve, optic chiasm, optic tracts, thalamus, optic radiation, visual cortex
Comes off diencephalon (CNS)
Myelinated by oligodendrocytes
Covered with the 3 CNS meninges (dura, arachnoid, Pia)
Can’t regenerate
Only sensory (visual info to the brain)
Afferent of pupillary reflex (efferent is on another nerve)
Optic Nerve (cranial nerve II)
Loss of function= blindness
Optic Nerve (cranial nerve II)
what is the flow of the optic nerve?
Retina, optic nerve, optic chiasm, optic tracts, thalamus, optic radiation, visual cortex
can the optic nerve regernate?
Can’t regenerate
Afferent of pupillary reflex (efferent is on another nerve)
Optic Nerve (cranial nerve II)
Raises eyelid and moves eyeball
Constricts iris (color part of eye- parasympathetic function)
carries parasympathetic fibers
Controls pupil restriction; efferent of pupil reflex (carries info out)
Innervates the eyeball muscles
Oculomotor (cranial nerve III)
Loss of function: Loss of function= down and out syndrome (superior oblique and lateral rectus muscle take over); aka one eye is closed
Unpaired only happens in cranial nerve 3
Oculomotor (cranial nerve III)
Down and out= 3 words= cranial nerve 3
ptosis=
dropping eyelid (weak elevator palpebrase superiors muscle)
Goes to superior oblique muscle
Smallest cranial nerve
Only cranial nerve that exits dorsal brain stem
Moves eye down and out when working alone
Trochlear (cranial nerve IV)
Loss of function= double vision (diplopia); patients will tilt their head to try to fix the visual field
Trochlear (cranial nerve IV)
Comes off pons
Sensory and motor
3 divisons:
ophtalmic (V1-sensory only)
maxillary (V2-sensory only)
mandibular (V3 sensory, supplies chewing muscles, and pain to anterior 2/3rd of tongue)
Largest of cranial nerve (basically whole face)
Trigeminal nerve (cranial nerve V)
Loss of function= loss of sensation, muscle paralysis on one side which leads to the jaw deviates to the paralyzed side
Trigeminal neuraligia= neuropathic disorder with severe pain in V1 and V2
Trigeminal nerve (cranial nerve V)
Trigeminal neuraligia= neuropathic disorder with severe pain in what crabches
V 1 and 2
Abduct
Lateral rectus muscle (moves eye laterally)
Abducens (cranial nerve VI)
Loss fx= can’t move eyeball laterally
H patterns to test for look at pen
Abducens (cranial nerve VI)
Has 5 divisions: temporal, zygomatic, buccal, mandibular, cervical (ten zebras bite my chicken)
motor
Facial expression
Autonomics impulses and salivary glands and crying
Taste to anterior 2/3rds of tongue
. Facial nerve (cranial nerve VII) - ST channel
Loss of fx= loss taste
. Facial nerve (cranial nerve VII) - ST channel
LMN lesion (on cranial nerve 7) leads to
bell palsy on half of face
_____ lesion= stoke in L brain effects R cranial verve 7; only lower half of face damaged on opposite side of stroke in brain
UMN
Hearing and balance
Sensory
Deafness
Vestibulocochlear (cranial nerve VIII)
Loss of vestibular info regarding head position
Test it by using tuning forks
Vestibulocochlear (cranial nerve VIII)
Swallowing Monitor and sensory Parasympathetic Parotid gland Taste and general sense on posterior 1/3 of tongue
Glossopharyngeal (cranial nerve IX)
Carries blood pressure into from carotid bodies to medulla oblongata
Glossopharyngeal (cranial nerve IX)
loss= taste on back 1/3rd of tongue, no parotid gland activity and uvula deviates to the strong side
Glossopharyngeal (cranial nerve IX)
Innervates pharynx and larynx (swallowing and speaking)
Efferent gag reflex
Innervates parasympathetic fibers (HT, LU, SP etc)
Taste on posterior 1/3rd of tongue
Blood pressure info from aortic body to the medulla oblongata
Vagus Nerve (cranial nerve X)
Loss of fx: hoarseness (dysphonia), difficult swallowing (dysphagia)
No parasympathetic dysfunction
Vagus Nerve (cranial nerve X)
Cranial root and spinal root
Innervates the traps and SCM
Accessory Nerve (cranial nerve XI)
oss of fx= weakness of trap and SCM
Accessory Nerve (cranial nerve XI)
Swallowing, speech, tongue position
Comes out from under tongue
Motor function
No sensory function
Hypoglossal (cranial nerve XII)
how many branches are there of cranial nerve 5?
3 branches:
- ophthalmic
- maxillary
- mandibular
how many branches are there of cranial nerve 7?
5
- temporal
- zygomatic
- buccal
- mandibular
- cervical
