Cranial Nerves Flashcards
One of the main differences between spinal nerves and cranial nerves?
Spinal nerves are both sensory and motor; cranial nerves can be both, or can be just motor or just sensory
Taste is carried by which cranial nerves? (3)
Facial (VII), glossopharyngeal (IX), and vagus (X)
Autonomic difference between spinal nerves and cranial nerves
Cranial nerves do not carry sympathetic fibers (all sympathetics in head are postsynaptic); spinal nerves carry sympathetic fibers
Where do cranial nerves synapse?
Superior cervical ganglion
Which cranial nerves carry parasympathetics? (4)
These target what muscles?
CN III, VII, IX, and X
Smooth muscles of the eye
In regard to the 4 cranial nerves that carry parasympathetics, which has a unique target, where is it?
Vagus nerve targets are outside head
Name all 12 cranial nerves in order
Olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory and hypoglossal
Which 4 cranial nerves move the eye muscles
III, IV, V, and VI
Difference in location of the special sensory nerves compared to the other cranial nerves?
Special sensory nerves emerge from the forebrain; other cranial nerves emerge from the brainstem
What are the 2 special sensory nerves?
Olfactory and optic
Olfactory nerve (CN I)
- Function
- Location
- Where do the fibers extend into?
- Other function that can help intensify your sense of smell?
- Sense of smell
- Cribriform plate of ethmoid bone
- Fibers go through holes of cribriform plate to the upper 1/3 of nasal cavity
- Moistening the air
~so only upper 1/3 of nasal cavity has a sense of smell
Optic nerve (CN II)
- Emerges from?
- Where do they crossover?
- What do they form after they crossover?
- Optic canal
- Optic chiasm
- Form optic tracts
Optic field for LEFT eye:
- Light coming from the left will go to which field?
- Light coming from the right will go to which field?
- At the optic chiasm, the signal from the nasal field of the left eye goes which direction? Temporal field?
- Temporal field of left eye (medial part of eye)
- Nasal field of left eye (lateral part of eye)
- Nasal field goes to the left of the left eye; temporal field goes to the right of the left eye
Optic field for RIGHT eye:
- Light coming from the left will go to which field?
- Light coming from the right will go to which field?
- At the optic chiasm, the signal from the nasal field of the right eye goes which direction? Temporal field?
- Nasal field of right eye
- Temporal field of right eye
- Nasal field will go right of the right eye; temporal field will go left of the right eye
Monocular blindness:
1. If you have a problem with your left optic nerve, you will have blindness in which 2 fields of view?
- Blindness in temporal AND nasal field of left eye