FE: Lecture 10 Cerebral Cortex Flashcards
What does the cerebral cortex contain?
grey matter- folded sheets of cortex
white matter- extrinsic- thalamocortical and corticospinal tracts
intrinsic- inter and intrahemispheric connections (ex. corpus callosum)
How many layers is the cerebral cortex comprised of?
3-6 layers
What is in the first layer of cerebral cortex?
only dendrites and axons
What are the 2-3 layers of the cerebral cortex?
allocortex/ archicortex
ex. hippocampus
What are the 4-5 layers of the cerebral cortex?
periallocortex- olfactory, piriform and some of cingulate, parahippocampal cortex
What is all 6 layers of cerebral cortex?
Neocortex/ Isocortex- almost all cortex
What is the layer structure according to Brodmann?
pyramidal layers- 3,5
granular cell layers- 2 and 4
fusiform layer 6
Why does BA 4 have a very large layer 5?
because this is where the corticospinal tract originates from
What is Brodmann’s area 1,2,3 for?
somatosensory sensation
What is BA 4?
motor cortex for fine motor control
What is BA 17?
visual cortex for conscious visual sensation
What is BA 41?
auditory cortex for auditory sensation
What is the major difference from human brains to all other types of brains?
size of the brain and the amount of cortex/gyri
What area is larger in humans than any other species?
association cortex
What is BA 6, 8, 9?
premotor, anterior to primary motor
damage to this area will result in bilateral loss of motor planning or delayed responses
What are BA 44, 45, 22?
language
speech 44, 45
understanding 22
What two gyri comprise BA 45, 44, 22?
inferior frontal (Broca’s) , superior temporal gyri (Wernike’s)
What is Broca’s aphasia?
loss of language- speaking and writing
What is Wernike’s aphasia?
loss of understanding language- cant listen or read
What does it mean that speech area is hemisphere dominant?
right handed people tend to be left side speech dominant (90%)
left handed people (40-80%) right side speech dominant
What are characteristics of Broca’s area?
halting speech, repeating words, disordered speech, comprehension intact
What are characteristics of Wernike’s aphasia?
fluent speech, weird/ inappropriate words, comprehension not intact
What are BA 5-7?
dorsal parietal association cortex, superior parietal lobule
major cause from damage is agnosia or “not knowing”
What are two specific agnosia’s?
object- astereognosis- inability to distinguish specific objects by touch
asomatognoisa- part of your body is not you, arm and finger
What are BA 19, 37, 20?
occipital and temporal association
damage leads to visual agnosia
What are two types of visual agnosia?
simultanagnosia- “book covering light bulb”
prosopagnosia- face recognition
What are BA 39, 40?
lateral parietal association cortex
knowing the existence of the world and everything in it
damage leads to contralateral neglect- can’t attend to contralateral vision field
if damage is on left side of brain stand on left side
What are the BA associated with me?
8, 9, 10, 46 and maybe 11 and 12 more recently 24 and 32
Where are all these areas?
prefrontal cortex and cingulate cortex
What are the functions of all these areas?
executive function- right from wrong, better from best etc.
prediction of outcomes of actions
social suppression of urges
emotions and affect
What is a frontal lobotomy?
damaging prefrontal cortex which will get rid of one’s personaility
What are four major regions of limbic lobe?
cingulate cortex, hippocampus (parahippocampal gyrus), piriform (olfactory cortex), orbitofrontal
Why is the limbic lobe sometimes called the smell brain?
because sense of smell ends in amgydala and piriform cortex
What is the route of sense of smell?
- olfactory epithelium
- olfactory bulb
- olfactory tract
- anterior commissure
- amygdala and piriform cortex
What is the limbic system?
limbic lobe plus :
- cingulum bundle
- fornix
- mammilary bodies
- anterior thalamus- internal capsule
damage affects emotion
More recently what is considered part of the limbic system?
mediodorsal nucleus, hypothalamus nuclei, nucleus accumbens, amygdala, ventral tegmental area, raphe, insula, medial prefrontal cortex
What are the three types of memory associated with limbic lobe?
- declarative- explicit
- procedural- implicit
- emotional
What is declarative memory?
lecture exam material- fact based short and long term
in the hippocampus, cingulate cortex, mammillary and anterior thalamus
What is procedural memory?
clinical practice exam memory- skilled movements
in the prefrontal cortex, basal ganglia
What is emotional memory?
what happens if I don’t study this weekend
in amygdala and orbitofrontal cortex
What are the output centers of the hypothalamus?
hypothalamic tract, controls pituitary gland - endocrine system
controls ANS, maintain homeostasis
What does the anterior and posterior stimulation elicit?
anterior- parasympathetic
posterior- sympathetic
damage leads to opposite stimulation
What are the four F’s of the hypothalamus?
feeding, fighting, fleeing and fucking
What are the two feeding disorders?
- hyperphagia- eat more damage to medial hypothalamus
2. aphagia- eat less damage to lateral hypothalamus
What other emotions does the hypothalamus produce?
rage and amgydala inhibits it- “delgado’s bull”
also produce fear- anxiety and fear
What part of the hypothalamus is the sex center?
anterior hypothalamus, lesion leads to lack of sex drive, stimulation is hyper sex drive
control of sex hormones by pituitary gland
