Section 1, Part 2: External Anatomy and blood supply Flashcards
What does the telencephalon include?
Cerebral hemispheres
cortex+ white matter + basal ganglia
What does the diencephalon include?
Thalmus + hypothalmus
What is another name for the mesencephalon?
Midbrain
What does the metencephalon include?
Cerebellum + Pons
What does the myelencephlon include?
Medulla
What does the forebrain refer to ?
Telencephalon + diencephalon
What does the Hindbrain refer to?
Metencephalon + myelencephalon
cerebellum + pons + medulla
What does the brain stem refer to?
Midbrain + pons + medulla
What sulci separates the parietal and frontal lobes?
Central sulcus
What sulci separates the temporal lobe from the parietal and frontal lobes?
Lateral sulcus
What is a sulcus? What is a gyrus?
Sulcus - fissure
Gyrus - bumps of tissues btwn fissures
What lobe is the precentral gyrus found in? What lobe is the postcentral gyrus found in?
precentral - frontal
postcentral - parietal
What two gyri make up the inferior parietal lobule?
Angular + supramarginal
Where is the visual cortex located?
Occipital lobe - area 17
In the occipital lobe, what gyrus is above the calcarine sulcus, what is below?
above - cuneus
below - lingual
Where is Heschl’s gyrus located? What is this associated with
Temporal lobe
-primary sensory cortex for audition
What is the back wall of the area in the lateral sulcus called?
Insula
What does the limbic lobe consist of?
parahippocampal + cingulate + subcallosal gyri
these all surround the corpus callosum
What is the seal covering the lateral ventricle called?
Septum pellucidum
What does the tectum in the midbrain consist of?
Superior + inferior colliculus
What does the cerebral peduncles in the midbrain consist of?
tegmentum + crus cerebri
What is the tegmentum?
portion of midbrain btwn tectum and crus cerebri
-gray matter of midbrain
What is the only cranial nerve that originates on the dorsal side of the midbrain (in the tectum)?
CN 4
What does the inferior cerebellar peduncle connect?
medulla to cerebellum
What does the middle cerebellar peduncle connect?
pons to cerebellum
What does the superior cerebellar peduncle connect?
cerebellum to midbrain and thalmus
In the Medulla, what is located more inferior and medially, the gracile or the cuneates?
gracile
Which cranial nerves originate in the medulla?
glossopharyngeal
vagus
hypoglossal
spinal accessory
9,10,11,12
If a patient presents with ataxic or disrupted breathing or irregular heartbeats what does this suggest?
The medulla is compromised
Which cranial nerves originate in the pons ?
5,6,7
What symptoms indicative of pontine dysfunction?
loss of sensation in the face
eye deviated medially
weakness of facial muscles
Where does cranial nerve 8 originate?
transition btwn the pons and medulla
What would be the symptoms of cranial nerve 8 dysfunction?
ipsilateral deficits in hearing or balance
Where do cranial nerves 3 and 4 originate?
The midbrain
How would midbrain disfunction appear?
dilated pupil
eye movements are restricted
What does a coma usually indicate?
involvement of the forebrain or midbrain
-tegmentum of midbrain controls levels of consciousness
Which nerves are forebrain nerves?
1 and 2
What symptoms are indicative of forebrain disease?
common - loss of vision
loss of smell, changes in mental functions
What is the largest component of the brain?
cerebral cortex - 85% by weight
What is the pathway of visual information?
thalmus->primary visual cortex or area 17-> occipital cortex -> parietal and temporal lobes
How do lesions of the occipital lobe manifest?
blind spots - scotomas in half of the visual field contralateral to the lesion
How is each side of the visual cortex interconnected with the other side?
splenium of the corpus callosum
What gyrus is associated with the somatosensory system?
postcentral gyrus
(SI or brodmann’s areas 3,1,2
How will damage to the postcentral gyrus manifest?
somatic sensory deficits on opposite side of the body
What is the superior parietal lobule associated with? How will a lesion in this area manifest?
guiding movement
apraxia or inability to bring limb under sensory or cognitive control
What is the inferior parietal lobule associated with?
dominant hemisphere (usually left) -language
supramarginal gyrus-wernicke’s - understanding language
angular gyrus -gateway for visual information to wernicke’s
How would damage to the angular gyrus manifest in the left hemisphere? right?
left - inability to read
right - spatial disability - neglect of left side
How would damage to the heschl’s cortex manifest?
one hemisphere - little deficit
both hemispheres - inability to understand spoken language since it is cut off from wernicke’s
What is the superior temporal gyrus associated with?
audition
- posterior portion - planum temporale - part of wernicke’s in dominant hemisphere
- important for understanding language
What are the middle, inferior temporal lobes and occipito-temporal gyri associated with ?
visual memory and perception
What is prospagnosia?
lesions of the inferior temporal lobe - inability to identify or recognize faces
What would result from a lesion of the parahippocampal gyrus and uncus?
bilateral damage -severe amnesia since these are associated with memory
How are the anterior regions of the temporal lobes and olfactory lobes connected?
anterior commisure
What is located at the precentral gyrus and what area number is it?
area 4
primary motor cortex
What would result from a lesion at the precentral gyrus?
weakness on the opposite side of the body
What is located at the superior and middle frontal gyri?
secondary motor and premotor areas
organization of voluntary movements
What would result from damage to the superior and middle frontal gyri?
forms of apraxia (understand task is asked but can’t perform it)
in dominant hemisphere - inability to write
What is another term for the inferior frontal gyrus in the dominant hemisphere? What is it’s function?
Broca’s area
programming of speech
What region of the brain is far more developed in humans than any other species? What is believed to be it’s function
prefrontal cortex
make-up of personality
planning and sequencing of complex tasks
What would result from damage to the prefrontal cortex?
altered personality
compulsive repetitive behaviors - inability to plan
How are the frontal lobes connected?
genu of the corpus callosum
Describe the pathway in which information about language is processed?
Speech information:
- enters the temporal cortex in heschl’s gyrus
- spreads to wernicke’s
Visual information:
-from occipital lobe to wernicke’s thru angular gyrus
-wernicke’s–>frontal lobe - Broca’s area
What areas does wernicke’s include?
supramarginal gyrus
superior temporal gyrus
What is wernicke’s aphasia?
inability to understand language and speak coherently
What is broca’s aphasia?
inability to generate speech but understands
