neuro 500 --- cerebral cortex Flashcards
Functional organization of cerebral cortex
Sensory areas
Motor areas
Association areas
Sensory areas of Cerebral cortex
receive sensory information and are involved in perception
Perception – the conscious awareness of a sensation
Motor areas of cerebral cortex
control the execution of voluntary movement
Association areas
deal with more complex integrative functions
i.e. memory, emotions, reasoning, judgment…
primary vs association area
Primary sensory areas
Sensory association areas
Primary sensory areas
receive sensory information from peripheral sensory receptors
Sensory association areas
are usually adjacent to primary sensory areas
- they receive input from the primary sensory areas and other brain areas
- they integrate sensory experiences to generate meaningful patterns of recognition & awareness
E.g. of sensory association area
when you see a table you’ve never seen before
you know it’s a table, even though you haven’t seen that one particular table before
primary somatosensory area
Brodmann’s area 1, 2 and 3
e.g. of somatic sensories
touch, temperature, pain, vibration, tickle, itch, proprioception (?)
where is postcentral area?
- in postcentral gyrus
- parietal lobe
- receives nerve impulses for touch, pressure, vibration, itch, tickle, temperature, pain, proprioception
- a map of the entire body is present here
‘sensory homunculus’
sensory homunculus
- each point in the area receives impulses from a specific part of the body
- size of the area in the brain depends on the number of receptors in that part of the body (nothing to do with the size of the body part)
theory of phantom limb (fyi)
unused part of cortex gets replaced with existing areas (from areas that still have innervation)
primary visual area
- Brodmann’s area 17
- receives visual information and involved in visual perception
primary auditory area
- Brodmann’s area 41 and 42
- receives auditory information and involved in auditory perception
Primary gustatory area
- Brodmann’s area 43
- receives impulses for taste and involved in gustatory perception and taste discrimination
@ insula (deep-folded lobe of the brain)
Primary olfactory area
- Brodmann’s area 28 (deep, not visible externally)
- receives impulses for smell and involved in olfactory perception
- medial
Primary motor area
- Brodmann’s area 4
- in precentral gyrus
- frontal lobe
map of entire body here ‘motor homunculus’
‘motor homunculus’
- each region controls voluntary contractions of specific muscles or groups of muscles
- electrical stimulation of any point here causes contraction of specific skeletal muscle fibers on the opposite side of the body
- bigger area for muscles involved in skilled complex or delicate movement
Broca’s speech area
ONLY FOUND ON ONE SIDE
(- in 97% of people it’s located in the left hemisphere)
- Brodmann’s area 44 and 45
- from here, impulses go to premotor areas that control speech muscles and to primary motor areas
Somatosensory association area
- Brodmann’s area 5 and 7
- receives input from primary somatosensory area, thalamus and other areas
- lets you determine the exact shape and texture of an object by feeling it
- also memory of past somatic sensory experiences
Visual association area
- Brodmann’s area 18 and 19
- receives input from primary visual area and thalamus
- relates present and past visual experiences
- is essential for recognizing and evaluating what is seen
Facial recognition area
- Brodmann’s area 20, 21 and 37
- receives impulses from visual association area
- stores information about faces, allows you to recognize people
- more dominant on right
facial recognition also activates during ____
E.g.
different species of trees (same overall shape, different details)
car types
etc.
Wernicke’s area
- Brodmann’s area 22, 39 and 40
- interprets meaning of speech by recognizing spoken words
- more dominant on LEFT (like Broca’s)
Prefrontal cortex
- Brodmann’s area 9, 10, 11 and 12
- has numerous connections with other areas of the
cerebral cortex, thalamus, hypothalamus, limbic system,
and cerebellum - personality, intellect, complex learning abilities, recall
of information, initiative, judgment, foresight,
reasoning, conscience, intuition, mood, planning for
future, development of abstract ideas
Premotor area
- Brodmann’s area 6
- communicates with primary motor cortex, sensory association areas, basal nuclei, thalamus
- deals with learned motor activities of a complex and sequential nature
- causes specific groups of muscles to contract in a specific sequence
p
pre-motor area —> primary motor area —> pyramids (??) / brainstem —> UMN/LMN
Frontal eye field area
- Brodmann’s area 8
- voluntary scanning of eyes
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Auditory association area
- Brodmann’s area 22
- lets you recognize a particular sound as speech, music or noise
Orbitofrontal cortex
- Brodmann’s area 11
- receives sensory impulses from the primary olfactory area
- allows you to identify odors and discriminate among different odors
- more dominant on the right
damage to language areas
-language areas are in left cerebral hemisphere
aphasia
-inability to use or comprehend words
nonfluent aphasia
-damage to Broca’s area
-inability to properly articulate or form
words
-know what they want to say but can’t say it
fluent aphasia
-damage to Wernicke’s, common
integrative area or auditory association area
-faulty understanding of spoken or written
words
- “word salad” –string of words with no meaning
