CRASH COURSE - Cranial Nerves

Question 1

what is the function of the olfactory nerve?

Answer 1

smell

Question 2

what is the function of the optic nerve?

Answer 2

sight

Question 3

what is the function of the oculomotor nerve?

Answer 3

• innervates SR, MR, IR, LPS
• pupil constriction via PNS

Question 4

what is the function of the trochlear nerve?

Answer 4

innervates SO

Question 5

what is the function of the trigeminal nerve?

Answer 5

sensation to face, diagastric, mylohyoid

Question 6

what is the function of the abducens nerve?

Answer 6

innervates lateral rectus

Question 7

what is the function of the facial nerve?

Answer 7

• innervates muscles of facial expression, stapedius, stylohyoid
• taste on anterior 2/3 of tongue
• innervates lacrimal/submandibular/sublingual glands via PNS

Question 8

what is the function of the vestibulocochlear nerve?

Answer 8

hearing and balance

Question 8

what is the function of the glossopharyngeal nerve?

Answer 8

• sensory innervation to pharynx, tonsils, middle ear, posterior 1/3 tongue
• innervates parotid gland, stylopharyngeus, carotid bodies/sinus

Question 9

what is the function of the vagus nerve?

Answer 9

• PNS to thoracic and abdominal viscera
• muscles of palate/pharynx/larynx
• inflammatory reflex

Question 10

what is the function of the accessory nerve?

Answer 10

innervates sternocleidomastoid and trapezius

Question 11

what is the function of the hypoglossal nerve?

Answer 11

intrinsic/extrinsic tongue muscles

Question 12

what is the location/nuclei for the olfactory nerve?

Answer 12

frontal lobe/limbic system

Question 13

what is the location/nuclei for the optic nerve?

Answer 13

visual pathway to occipital lobe

Question 14

what is the location/nuclei for the trochlear nerve?

Answer 14

midbrain - trochlear motor nucleus

Question 15

what is the location/nuclei for the trigeminal nerve?

Answer 15

pons - trigeminal sensory/motor nucleus

Question 16

what is the location/nuclei for the abducens?

Answer 16

pons - abducens nucleus

Question 17

what is the location/nuclei for the facial nerve?

Answer 17

pons - facial motor nucleus, nucleus solitarius, superior salivary nucleus

Question 18

what is the location/nuclei for the vestibulocochlear nerve?

Answer 18

pons - vestibulocochlear nucleus

Question 19

what is the location/nuclei for the glossopharyngeal nerve?

Answer 19

medulla - nucleus ambiguus, nucleus solitarius, inferior salivary nucleus

Question 20

what is the location/nuclei for the vagus nerve?

Answer 20

medulla - nucleus ambiguus, nucleus solitarius, dorsal motor nucleus of vagus

Question 21

what is the location/nuclei for the accessory nerve?

Answer 21

medulla and c-spine - nucleus ambiguus, C1-C5

Question 22

what is the location/nuclei for the hypoglossal nerve?

Answer 22

medulla - hypoglossal motor nucleus

Question 23

what skull foramina does the olfactory nerve pass through?

Answer 23

cribiform plate

Question 24

what skull foramina does the optic nerve pass through?

Answer 24

optic canal

Question 25

what skull foramina does the occulomotor nerve pass through?

Answer 25

superior orbital fissure

Question 26

what skull foramina does the trochlear nerve pass through?

Answer 26

superior orbital fissure

Question 27

what skull foramina does the trigeminal nerve pass through?

Answer 27

opthalmic V1 - superior orbital fissure maxillary V2 - foramen rotundum mandibular V3 - foramen ovale

Question 28

what skull foramina does the abducens nerve pass through?

Answer 28

superior orbital fissure

Question 28

what skull foramina does the facial nerve pass through?

Answer 28

internal acoustic meatus

Question 29

what skull foramina does the vestibulocochlear nerve pass through?

Answer 29

internal acoustic meatus

Question 30

what skull foramina does the glossopharyngeal nerve pass through?

Answer 30

jugular foramen

Question 31

what skull foramina does the vagus nerve pass through?

Answer 31

jugular foramen

Question 32

what skull foramina does the accessory nerve pass through?

Answer 32

foramen magnum to jugular foramen

Question 33

what skull foramina does the hypoglossal nerve pass through?

Answer 33

hypoglossal canal

Question 34

what cranial nerves have contralateral innervation only?

Answer 34

hypoglossal CNXII

Question 35

what cranial nerves have bilateral innervation?

Answer 35

oculomotor (CNIII) trochlear (CNIV) trigeminal (CNV) abducens (CNVI) glossopharyngeal (CNIX) vagus (CNX) accessory (CNXI)

Question 36

what are the 3 ascending sensory tracts?

Answer 36

* dorsal columns (spinal) * spinothalamic (spinal) * trigeminothalamic (cranial)

Question 37

what are the 2 descending motor tracts?

Answer 37

* corticospinal (spinal) * corticobulbar (cranial)

Question 38

what info does the dorsal column carry?

Answer 38

fine touch, two point discrimination, vibration, proprioception

Question 39

how many neurons are in the dorsal column? where are the synapses?

Answer 39

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

Question 40

where does the dorsal column decussate?

Answer 40

medulla oblongata

Question 41

signals from the upper limb (T6 and above) travel in what part of the dorsal column?

Answer 41

fascisulus cuneatus

Question 42

signals from the lower limb (below T6) travel through which part of the dorsal column?

Answer 42

fasciculus gracilis

Question 43

what information does the anterior spinothalamic tract carry?

Answer 43

anterior - crude touch and pressure lateral - pain and temperature

Question 44

how many neurones are there in the spinothalamic tract? where do they synapse?

Answer 44

1 - sensory receptors in periphery and synapse in substansia gelatinosa 2 - decussate and synapse in thalamus 3 - thalamus to ipsilateral primary sensory cortex

Question 45

where does the spinothalamic tract decussate?

Answer 45

spinal cord

Question 46

what is the role of the corticospinal tract?

Answer 46

supplies the musculature of the body

Question 47

what is the role of the corticobulbar tract?

Answer 47

supplies the musculature of the head and neck

Question 48

where does the corticospinal tract decussate and synapse?

Answer 48

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

Question 49

where does the corticobulbar tract synapse?

Answer 49

from primary motor cortex through internal capsule to brainstem where it synapses with the motor nuclei of the cranial nerves.

Question 50

label this diagram of the trigeminal nuclus

Answer 50

Question 51

label the skull foramina and what CN pass through them

Answer 51

Question 52

label the cranial nerves

Answer 52