11. Cranial nerves Flashcards
(54 cards)
How many cranial nerves are there in the PNS
12 pairs of cranial nerves
How many spinal nerves are there in the PNS
31 pairs of spinal nerves
What is the function of the superior sagittal sinus in the skull
has venous veins that carry blood and CSF away, we need to drain CSF because we produce more than needed to circulate in the CNS.
What are the 3 reflections of the dura?
- Falx cerebri
- Tentori cerebelli
- Falx cerebelli
What is the function of the falx cerebri ?
It is an extension of the dura that separates the 2 hemispheres of the cerebrum
What is tentori cereblli
It is the extension/reflection of the dura, provides a passage for the midbrain. it intervenes between the cerebellum and occipital lobe
What is flax cerebelli
It is reflection of the dura that separates the cerebellar hemisphere.
Where do the cranial nerves arise from
arise from motor, sensory and autonomic nuclei of the brainstem
What happens when the spinal cord opens up to the back.
at the level of the medulla, the central canal is pushed to the side and opened, central canal moves back and opens up- which then have the nuclei present that give rise to the cranial nerves
what type of nerve is CN1 (olfarctory)
pure sensory nerve
Where does CN1 open at
cribiform plate of the ethmoid bone, it is from the olfactory bulb ( sensory ganglion- contains neurons)
Where does the olfactory tract travel
IT DOES NOT PASS THROUGH THE THALAMUS unlike other cranial nerves - goes from olfactory cortex to cerebrum
Where do optic nerves cross each other
optic chiasm
Do all fibers of the optic nerve cross the midline/optic chiasm?
no
What type of nerve is CN2?
purely sensory nerve
Where is the opening of CN2?
optic canal
What is the difference between the optic nerve and optic tract
optic tract has to pass through the thalamus ( bunch of nuclei), it is the point pass the optic chiasm
What is the lateral genoculate body/nucleus
part of the thalamus that receives the optic tract and relays the sense of vision to to the visual cortex at the occipital lobe
what is the name of the nerves after it has passed the lateral genoculate body
optic projection fibers
What are the components of the oculomotor nerve (CN3)
motor and autonomic
What is the function of CN 3
it is a nerve that innervates some of the eyeball.
Where is the opening of CN3
superior orbital fissure
What is the function of CN4 trochlear
controls one of the muscles of the eye
What is the function of CN6 abductens
same as CN 4. controls one of the muscles of the eye
