Lab Section 1 Flashcards
What is the difference between the telencephalon and the forebrain?
the telencephalon are the cerebral hemispheres while the forebrain also includes the diencephalon (thalamus and hypothalamus)
what is included in the hindbrain?
the metencephalon and the myelencephalon (the pons, cerebellum and medulla)
what are the metencephalon, myelencephalon and mesencephalon?
mes: midbrain
met: pons and cerebellum
myelen: medulla
where is the parieto-occipital fissure located?
it can be visualized with a medial view of the half brain separating the parietal and occipital lobes
what is the preoccipital notch?
a notch between the parietal and occipital lobes that can be visualized on the infero lateral view of the brain
where are the supramarginal and angular gyri located?
supramarginal: at the corner of the lateral fissure
angular: at the corner of the superior temporal sulcus
what separates the superior and inferior parietal lobules?
the intraparietal sulcus
describe the distribution of sulci and gyri within the occipital lobe.
the calcarine sulcus can be visualized in the medial aspect of the half brain. Superior to the sulcus is the cuneus gyrus and the lingual gyrus lies beneath it
what is another name for the fusiform gyrus? where is it located?
the occipito-temporal gyrus
located just medial to the inferior temporal gyrus on the inferior view of the brain
what is the order of gyri when looking at the inferior aspect of the brain from lateral to medial?
inferior temporal gyrus
fusiform gyrus
parahippocampal gyrus
what gyrus includes the uncas?
the parahippocampal gyrus
which gyrus does heschl’s gyrus lie on top of?
the superior temporal gyrus
how do heschl’s gyrus and he planum temporale relate?
both are on the superior temporal gyrus
the planum temporale lies posterior to the gyrus
what is another name for the parolfactory gyrus? where is it located?
the subcallosal gyrus
located below the genu of the corpus callosum
what is the name of the sheath covering the lateral ventricle from the medial view?
the septum pellucidum
what opening connects the lateral ventricle with the third ventricle?
interventricular foramen
where does the anterior perforated substance lie?
between the olfactory tracts and the optic tracts
what is contained within the tectum of the midbrain? where is it located?
the superior and inferior colliculi
located dorsal to the cerebral aqueduct
what does the brachium of the inferior colliculus connect?
the inferior colliculus and the medial geniculate body
where does the tegmentum of the midbrain and pons exist?
midbrain: ventral to the cerebral aqueduct
pons: dorsal to the basis of the pons but ventral to the cerebral aqueduct
what is contained within the cerebral peduncles?
the tegmentum and the crus cerebri (including the substantia nigra)
which cranial nerves are associated with the midbrain? where are they located?
cranial nerves three and four
III- ventral midbrain coming out of the interpeduncular fossa
IV- coming out of the dorsal aspect of the midbrain, directly below the inferior colliculi
what is the only cranial nerve that exits on the dorsal brainstem?
CN IV
which cranial nerves are associated with the pons? where are they located?
CN V-VII
V- exits at the middle of the pons laterally
VI- exits at the junction of the pons and the medulla medially
VII- exits at the junction of the pons and medulla laterally
what are the names of CN IV and VI and what muscles do they supply?
IV- trochlear; superior oblique
VI- abducens; lateral rectus
where can the facial colliculus be found?
within the 4th ventricle in the region of the pons
what are the three external structures of the cerebellum?
the vermis, hemispheres and flocculus
where is the flocculus of the cerebellum?
on the ventral view next to the exit of CN IX-XI
what do each of the three cerebellar peduncles connect to?
superior: midbrain and thalamus
middle: pons
inferior: medulla
where is the vestibular area located?
located within the fourth ventricle at the widest part
a lateral recess
where are the vagal and hypoglossal trigones?
in the meduallary portion of the 4th ventricle at the tip before it closes
of the somatosensory system, what can be seen on the external anatomy of the medulla?
the gracile and cuneate tubercles (bumps directly below the fourth ventricle)- gracile more medial than cuneate
gracile and cuneate fasciculi (tracts below the respective tubercles)
what cranial nerves are associated with the medulla?
CN VIII-XII
which three cranial nerves are clustered together and where do they exit?
CN IX-XI
come out behind the inferior olives
where do the vestibulocochlear and hypoglossal nerves exit the medulla?
VIII exits at the junction of the medulla and pons, lateral to VII
XII exits between the pyramids and inferior olive
what characterizes meduallary damage? why?
ataxic or disrupted breathing or irregular heartbeats
because the medullary cranial nerves control breathing and heart rate
what cranial nerve signs characterizes pontine damage?
loss of sensation in the face, medial strabysmus or weakness of facial muscles
what is associated with CN VIII damage?
loss of ipsilateral hearing
what cranial nerve signs characterizes midbrain damage?
dilated pupil or restricted eye movements
what does coma usually indicate?
midbrain or forebrain damage
what cranial nerve signs indicate forebrain disease?
loss of smell or vision (more commonly) because they are located at the forebrain
what does changes in mental status indicate?
forebrain involvement
how many layers are there in the neocortex?
6
what connects the two visual cortices?
the splenium of the corpus callosum
what is the superior parietal lobule responsible for? what would lesions to this area cause?
guiding movement
lesions could cause apraxia
what is apraxia?
inability to execute learned movements despite the desire and physical capacity (disorder of motor planning)
what is the role of the angular gyrus? what would happen if it were damaged?
to provide Wernicke’s area with visual information
if damaged- patient cannot read
what connects the parietal lobes and the posterior parts of the frontal lobe bilaterially?
the body of the corpus callosum
where is the primary auditory cortex located? what happens if there is damage to it bilaterally?
Heschl’s gyrus
bilateral damage would cause inability to understand spoken language because auditory info is not passed on to Wernicke’s area
what two structures make up Wernicke’s area?
the planum temporale and supramarginal gyrus on the dominant hemisphere
what would result from bilateral damage to the inferior temporal lobe?
prosopagnosia- inability to recognize and ID faces
which gyrus is particularly involved in the recognition of faces?
the fusiform gyrus
what is the result of bilateral damage to the parahippocampal gyri and uncas?
severe amnesia
what is interconnected by the anterior commisure?
the anterior parts of the temporal lobes and olfactory lobes
what is contained within the olfactory lobes?
regions receiving terminations of the olfactory tract including the uncas, anterior part of the parahippocampal gyrus and subcallosal gyrus
what would result from superior and middle frontal gyri damage to the posterior portions?
apraxia including inibility to write if in the dominant hemisphere and disorganization of eye movements
where is broca’s area? what results from damage to that area?
the posterior portion of the inferior frontal gyrus in the dominant hemisphere
damage results in inability to generate fluent speech or writing (although understanding is fine)
what portion of the brain does the prefrontal cortex include? What would be the symptoms of its damage?
the rostral portions of the superior, middle and inferior gyri
damage would lead to personality changes and compulsive repetitive behaviors related to their impaired ability to plan complex behaviors
what connects the two frontal lobes?
the genu of the corpus callosum
what are the two branches off of the vertebral arteries before they join?
the anterior spinal artery, two posterior spinal arteries and the posterior communicating arteries
what are the main branches of the basilar artery and what are the terminal branches?
branches before termination: anterior inferior cerebellar arteries, perforating pontine arteries, superior cerebellar arteries
terminates into the two posterior cerebral arteries
what do the posterior communicating arteries connect?
connects the posterior cerebral to the junction between the internal carotid artery and the middle cerebral artery
what vessel do the lenticulostriate arteries branch from?
the middle cerebral arteries
what do the vertebral arteries branch from?
the subclavian arteries
in what conditions will occlusion of an artery be corrected by perfusion of the anastomoses and in which condition will it not?
if one part of the circulation connected in the circle of willis is occluded gradually, it will more likely to have collateral blood flow from the anastomoses be sufficient (will not if sudden loss of bloodflow)
what reinforces the blood flow to the posterior and anterior spinal arteries?
bloodflow from segmental branches of the aorta
where do the vertebral arteries join? where does AICA come off?
near the junction of the medulla and the pons
AICA comes off at or just after the joining of the basilar artery
branches off of the posterior communicating artery supply which structures?
the thalamus, midbrain and crus cerebri
what blood vessels depart from the internal carotid before it enters the scull?
the opthalmic arteries
what blood vessel supplies the insula?
the middle cerebral artery
where does the anterior choroidal artery depart and what does it supply?
departs from the junction of the middle and anterior cerebral arteries
supplies the anterior choroidplexus, the hippocampus, and the posterior part of the internal capsule
what do the lenticulostriate arteries supply?
the basal ganglia and parts of the internal capsule
what gyri are associated with the limbic lobe?
the subcallosal, cingulate and parahippocampal gyri
