CRASH COURSE - Cranial Nerves Flashcards
what is the function of the olfactory nerve?
smell
what is the function of the optic nerve?
sight
what is the function of the oculomotor nerve?
- innervates SR, MR, IR, LPS
- pupil constriction via PNS
what is the function of the trochlear nerve?
innervates SO
what is the function of the trigeminal nerve?
sensation to face, diagastric, mylohyoid
what is the function of the abducens nerve?
innervates lateral rectus
what is the function of the facial nerve?
- innervates muscles of facial expression, stapedius, stylohyoid
- taste on anterior 2/3 of tongue
- innervates lacrimal/submandibular/sublingual glands via PNS
what is the function of the vestibulocochlear nerve?
hearing and balance
what is the function of the glossopharyngeal nerve?
- sensory innervation to pharynx, tonsils, middle ear, posterior 1/3 tongue
- innervates parotid gland, stylopharyngeus, carotid bodies/sinus
what is the function of the vagus nerve?
- PNS to thoracic and abdominal viscera
- muscles of palate/pharynx/larynx
- inflammatory reflex
what is the function of the accessory nerve?
innervates sternocleidomastoid and trapezius
what is the function of the hypoglossal nerve?
intrinsic/extrinsic tongue muscles
what is the location/nuclei for the olfactory nerve?
frontal lobe/limbic system
what is the location/nuclei for the optic nerve?
visual pathway to occipital lobe
what is the location/nuclei for the trochlear nerve?
midbrain - trochlear motor nucleus
what is the location/nuclei for the trigeminal nerve?
pons - trigeminal sensory/motor nucleus
what is the location/nuclei for the abducens?
pons - abducens nucleus
what is the location/nuclei for the facial nerve?
pons - facial motor nucleus, nucleus solitarius, superior salivary nucleus
what is the location/nuclei for the vestibulocochlear nerve?
pons - vestibulocochlear nucleus
what is the location/nuclei for the glossopharyngeal nerve?
medulla - nucleus ambiguus, nucleus solitarius, inferior salivary nucleus
what is the location/nuclei for the vagus nerve?
medulla - nucleus ambiguus, nucleus solitarius, dorsal motor nucleus of vagus
what is the location/nuclei for the accessory nerve?
medulla and c-spine - nucleus ambiguus, C1-C5
what is the location/nuclei for the hypoglossal nerve?
medulla - hypoglossal motor nucleus
what skull foramina does the olfactory nerve pass through?
cribiform plate
what skull foramina does the optic nerve pass through?
optic canal
what skull foramina does the occulomotor nerve pass through?
superior orbital fissure
what skull foramina does the trochlear nerve pass through?
superior orbital fissure
what skull foramina does the trigeminal nerve pass through?
opthalmic V1 - superior orbital fissure
maxillary V2 - foramen rotundum
mandibular V3 - foramen ovale
what skull foramina does the abducens nerve pass through?
superior orbital fissure
what skull foramina does the facial nerve pass through?
internal acoustic meatus
what skull foramina does the vestibulocochlear nerve pass through?
internal acoustic meatus
what skull foramina does the glossopharyngeal nerve pass through?
jugular foramen
what skull foramina does the vagus nerve pass through?
jugular foramen
what skull foramina does the accessory nerve pass through?
foramen magnum to jugular foramen
what skull foramina does the hypoglossal nerve pass through?
hypoglossal canal
what cranial nerves have contralateral innervation only?
hypoglossal CNXII
what cranial nerves have bilateral innervation?
oculomotor (CNIII)
trochlear (CNIV)
trigeminal (CNV)
abducens (CNVI)
glossopharyngeal (CNIX)
vagus (CNX)
accessory (CNXI)
what are the 3 ascending sensory tracts?
- dorsal columns (spinal)
- spinothalamic (spinal)
- trigeminothalamic (cranial)
what are the 2 descending motor tracts?
- corticospinal (spinal)
- corticobulbar (cranial)
what info does the dorsal column carry?
fine touch, two point discrimination, vibration, proprioception
how many neurons are in the dorsal column? where are the synapses?
1 - dorsal root ganglia and extends through fasciculus gracilis and cuneatus
2 - synapses at nucleus gracilis or cuneatus
3 - synapse in thalamus and go to sensory cortex
where does the dorsal column decussate?
medulla oblongata
signals from the upper limb (T6 and above) travel in what part of the dorsal column?
fascisulus cuneatus
signals from the lower limb (below T6) travel through which part of the dorsal column?
fasciculus gracilis
what information does the anterior spinothalamic tract carry?
anterior - crude touch and pressure
lateral - pain and temperature
how many neurones are there in the spinothalamic tract? where do they synapse?
1 - sensory receptors in periphery and synapse in substansia gelatinosa
2 - decussate and synapse in thalamus
3 - thalamus to ipsilateral primary sensory cortex
where does the spinothalamic tract decussate?
spinal cord
what is the role of the corticospinal tract?
supplies the musculature of the body
what is the role of the corticobulbar tract?
supplies the musculature of the head and neck
where does the corticospinal tract decussate and synapse?
lateral - decussates in medulla and synapses with LMN in ventral horn
anterior - decussates in spinal cord and synapses in ventral hown in cervical and upper thoracic levels
where does the corticobulbar tract synapse?
from primary motor cortex through internal capsule to brainstem where it synapses with the motor nuclei of the cranial nerves.
label this diagram of the trigeminal nuclus
label the skull foramina and what CN pass through them
label the cranial nerves
