11. Cranial nerves Flashcards
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
How many cranial nerves control the movement of the eye
3 cranial nerves ( CN 3,4,6). there are also 7 muscles
Where is the opening of CN 4
superior orbital fissure
Where is the opening of CN 6
superior orbital fissure
What is the ganglion associated with CN5, what ganglion is it
semilunar ganglion. sensory neuron
What are the 3 divisions of the semilunar ganglion
- opthalmic branch -
- maxillary branch
- mandibullar branch
What is the function of the opthalmic branch of CN5
supplies general sense (pain, touch, temp) to the eye and forehead
What is the function of the maxillary branch of CN 5
sensory neurons to upper teeth and palate.
What is the function of the mandibular branch of CN 5
It is mixed branch (sensory and motor).
sensory innervates teeth of lower jaw and skin of mandible and tongue (general sense)
Motor fibers: muscles to move mandible - chewing
Where is the opening of the opthalmic division of CN 5
superior orbital fissure
Where is the opening of the maxillary branch of CN 5
foramen rotundum
Where is the opening of the mandibular branch of CN 5
foramen ovale
What ganglion does CN 7 associate with
geniculate ganglion, pterygopalatine ganglion and submandibular ganglion
What type of ganglion is the geniculate ganglion
sensory neuron
What are the components of the facial nerve
sensory, motor and autonomic
Where is the opening of the facial nerve
internal acoustic meatus
Where is the opening of CN 8
internal acoustic meatus
What is the function of the vestibulocochlear neuron
hearing and balance
What type of nerve is CN 8
purely sensory
Where is the opening of CN 9
jugular foramen
What are the components of the glossopharyngeal
sensory, motor and autonomic
What are the functions of CN 9
taste and general sensation of the tongue, detect blood pressure
What is the opening of CN 10
jugular foramen
What are teh ganglions associated with CN 10
superior and inferior ganglion of the vagus nerve - BOTH SENSORY
Which cranial nerve leaves the head and neck
CN 10
What is the function of cardia plexus
it slows down beating of heart
What does the celiac plexus control
stomach, spleen,liver, pancrease
What does the hypogastric plexus control
all of the small intestine , 1/2 of the large intestine - entirely parasympathetic
Where is the opening of CN 12
jugular forman
What component is CN 12
motor nerve
What is the function of CN 12
supplies muscles of the tongue
