Neuroanatomy 5 Flashcards
What is the reticular formation?
scattered nuclei forming a network that integrate cranial nerve responses
What is found in the organ of corti?
inner and outer hair cells
What is the spiral ganglion?
bipolar neurons stimulated by hair cells and carrying APs from organ of corti to cochlear nuclei in pons
What happens to fibres after the cochlear nuclei?
some cross over and some dont
What tract do fibres travel in after the superior olivary nucleus?
lateral lemniscus
What nucleus do fibres travel to after the cochlear nuclei?
superior olivary nucleus
What two regions does the lateral lemniscus join?
superior olivary nucleus to the inferior colliculus
What body do fibres create as they decussate after the cochlear nuclei?
trapezoid body
What is the superior olivary nucleus important in?
analysis of sound esp. in the horizontal plane
What joins the inferior colliculi to the thalamus?
inferior brachium
Where in the thalamus do sound fibres synapse?
medial geniculate body
Where is the primary auditory cortex located?
superior posterior thalamus, buried a little in the lateral fissure
What do sound fibres travel in from the thalamus to the primary auditory cortex?
internal capsule
Where do fibres carrying low frequency sound end in the auditory cortex?
anterolateral part
Where do fibres carrying high frequency sound end in the auditory cortex?
posteromedial part
Where is Broca’s area located?
superior to the lateral fissure in the frontal lobe
Where is Wernkicke’s area located?
surrounding the pimrary auditory cortx posteroinferiorly
What happens if there is damage to Broca’s area?
struggle to produce language but can comprehend language
What happens if there is damage to Wernicke’s area?
difficulty understanding language
What is the first synapse of the vestibular fibres?
vestibular ganglion- just as fibres leave the labyrinth
Where ist he second synapse of vestibular fibres?
vestibular nuclei in the medulla
What connections does the vestibular nuclei have?
thalamus; nuclei of CNs III, IV, VI; cerebellum and spinal cord
What tract do vestibular fibres descned within the spinal cord in?
vestibulospinal tracts
what is the function of the vestibulospinal tracts?
excite limb extensors
What area of the cerebullum do vestibular fibres travel to?
folliculonodular lobe
Where does the optic nerve begin?
ganglia in the retina
What is the first main synapse of the visual pathway once out of the eye?
lateral geniculate nucleus in thalamus
Where do fibres involved in the pupillary light reflex terminate?
pretectal area and superior colliculus
Where is the primary visual cortex located?
above and below the calcarine sulcus of the occipital lobe
Where do neurones of the pretectal area project?
bilaterally to the edinger-westphal nuclei
Where is the lower visual field projected to in relation to the calcarine sulcus?
gyrus superior to the calcarine sulcus
Which fibres are carried in Meyer’s loop?
upper half of the visual field
What is Meyer’s loop?
a loop of fibres from the lateral geniculate body around the temporal part of the lateral ventricle
Why do some fibres leave the optic chiasm to go to the hypothalamus and pineal gland?
invovled in diurnal rhythms
What areas of the brain have roles in eye movement?
visual cortex and the frontal eye fields
What is the difference between the movements of the visual cortex and the frontal eye fields?
the visual cortex gives movements in response to visual stimuli whereas the frontal eye field is invovled in movements of command which tend to be jumpy (saccadic) rather than smooth
Where is the primary gustatory area located?
posteroinferiorly in the frontal lobe
What is the function of association fibres?
connect cortical sites lying in the same hemisphere
What is the function of commisural fibres?
connect one hemisphere to the other, usually connecting areas with similar function
What is the function of projection fibres?
connect hemispheres to deeper structures
What do the deep cerebral veins drain?
internal structures of the forebrain
What do the deep cerebral veins in each cerebral hemisphere merge to form?
internal cerebral vein
What do the internal cerebral veins in each hemisphere join to fom?
the great cerebral vein of Galen
Where does the great cerebral vein of Galen lie?
beneath the corpus callosum
What does the great cerebral vein of Galen drain into?
straight sinus
Where is the straight sinus found?
in the midline of tentorium cerebelli
Where do the superficial veins lie?
in the subarachnoid space
What are the dural venous sinuses?
channels formed between the two layers of dura mater
Where is the superior sagittal sinus found?
along line where the falx cerebri attaches to the interior of the cranium
Where is the inferior sagittal sinus found?
free border of the falx
What does the inferior sagittal sinus drain into?
straight sinus
What drains into the confluence of the sinuses?
superior sagittal sinus and straight sinus
Where is the confluence of the sinuses found?
internal occipital protuberance
What does the confluence of the sinuses drain into?
transverse sinus
Where sis the transverse sinus found?
along line of the attachment of tentorium to the occipital lobe
What does the transverse sinus drain into?
sigmoid sinus
Where are the cavernous sinuses found?
lateral to the body of sphenoid
What drains in to the cavernous sinuses?
middle cerebral vein
What does the cavernous sinses drain into the IJV via?
inferior petrosal sinus
What does the cavernous sinus drain into the transverse sinus via?
superior petrosal sinus
What does the sigmoid sinus drain into?
IJV
What joins the cavernous sinuses?
intercavernous sinuses
