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26 terms

Dr Najeeb Cranial nerves 1

Which cranial nerves do not originate from the brain stem?
1 and 2, olfactory and optic
What type of cells recieve information from the mucous membrane at the roof of the nose?
Bipolar cells, peripheral processes receive info from the membrane, central processes bundle through the holes in the cribriform plate.
How many pairs of cells are there going through the cribriform plate to the olfactory bulb?
15 to 20
Is the olfactory bulb a nerve and describe the route of an action potential.
Mitral cells to tract to stria (3) to primary olfactory cortex on the temporal lobe. (over the uncus)
Is the optic nerve a true nerve?
No, it is an elongation of the diencephalon. They are derivations of the lateral geniculate body located on the lateral side of the thalamai.
The olfactory nerve is located in what part of the brain (general/more specific/more specific)
Forebrain (prosencephalon), telencephalon, olfactory bulb
GIve 2 reasons to support the view that the optic nerve (2) is not a true nerve.
Is supported by oligodendrio glia (?) not Scwann cells and is affected by diseases like multiple sclerosis which is atypical
Is the retina an elongation of the diecephalon?
Describe the route eye to ...
Retina, optic nerve, optic chiasma, optic tract RADIATA??
Where do nerves 3 and 4 connect with the CNS?
Oculomotor and trochlear midbrain (mesencephalon)
Describe the position of CNS connection for 3 and it's exit in more detail.
3= connects with the peri-aquaductal grey matter then moves anteriorly through the red nucleus, through substantia nigra and out medially through the cerebral peduncle into the inter-peduncular fossa (csf) at the level of the superior colliculus
Describe the position of CNS connection for 4 and it's exit in more detail.
U/neath 3 (oculomotor) in the midbrain at the level of the inferior colliculus. 4 (trochlear) are the only ones that emerge out the back, they then cross and loop around the midbrain.
What role does the inferior colliculus have?
Very important connection with the auditory system.
Where does 5 connect? Goes where initially?
The trigeminal = Mid pons to trigeminal ganglion.
From the trigeminal ganglion how many and what divisions? Sensory or motor?
3 opthalmic, maxillary and mandibular. All are sensory with an additional motor in the mandibular division.
Where does 6,7,and 8 connect?
Abducent, Facial, Vestibular cochlear. At the ponto-cerebellar junction (between pons and medulla) with 6 being medial and 8 the most lateral.
9,10,11cr connect where?
Glosso pharyngeal, Vagus, spinal accessory cranial part connect at the post olivary sulcus of medulla
What does the abducent (6) do ?
Abducts the eyeball using the lateral rectus muscle,
Describe the spinal part of 11
Out of the spine between the dorsal and ventral roots and up through the foramen magnum to shake hands with the cranial part of 11.
Where does 12 connect?
The pre olivary sulcus of medulla
Once in the cranial cavity through which foramen do 1 + 2 exit?
Cribriform plate
Optic canals
Once in the cranial cavity through which foramen do 3,4,5a + 6 exit?
Superior orbital fissure
Once in the cranial cavity through which foramen do 5b + 5c exit?
Foramen rotundum trigeminal ganglion???foramen ovale??
Once in the cranial cavity through which foramen do 7 + 8 exit?
Internal auditory canal
Once in the cranial cavity through which foramen do 9,10 + 11 exit?
Foramen Jewla??
DRAW the skull foramens