Cranial nerves ( function and palsies ) Flashcards
1
Q
Cranial nerve 1
A
Olfactory nerve
2
Q
Function of cranial nerve 1
A
Smell
3
Q
Pathway of cranial nerve 1
A
Cribiform plate
4
Q
Cranial nerve 1 palsy
A
- head injury
- tumor of olfactory groove
- olfaction is temporarily lost after upper respiratory tract infection
5
Q
Cranial nerve II
A
Optic nerve
6
Q
visual pathway
A
- Light allowed in by pupillary aperture
- light is converted to action potential by retinal rod, cone and ganglion cells
- Nasal visual field -> temporal retina
- Temporal visual field -> Nasal retina
- Axons from the optic nerve decussate at the optic chiasm
- fibres from the nasal retina cross to form the optic tract
- each optic tract carres information from the contralateral visual hemisphere
- Reach lateral genticulate body
- then pass in the optic radiation through the pariteal and temporal lobes to reach the visual cortex of the occipital lobe
7
Q
Ipsilateral mononuclear blindless
A
complete optic nerve lesion
8
Q
bitemporal hemianopia
both temporal visual fields
A
- lesion at the optic chiasm
9
Q
Homonymous hemianopia
right or left - one nasal field and one temporal field of each eye
A
- lesion at optic chiasm
10
Q
homonymous quadrantanopia
A
- temporal lesiom
11
Q
homonymous hemianopia with macular sparing
A
lesion at the optic cortex
12
Q
cranial nerve III
A
Occulomotor nerve
13
Q
cranial nerve III function
A
- Eye movement
- Medial rectus
- Inferior rectus
- Superior rectus
- Inferior oblique - Levator Palpebrae superioris -
- Pupillary constriction
- Accomadation
14
Q
Pathway of Cranial nerve III
A
- Superior orbital fissue
15
Q
Cranial nerve III palsy
A
Palsy results in
- ptosis
- ‘down and out’ eye
- dilated, fixed pupil