Lecture 2 Flashcards
List the four (five) lobes of the cerebral cortex, and state the major functions of each lobe.
frontal--prefrontal associat parietal temporal occipital insular
Label a diagram to show the location of key cortical regions
ye
Map sensory and motor function for the various regions of the body to the cortical “homunculus”; and describe the main arterial supply to each region of the motor and sensory homunculus.
ye
Describe how the different cortical regions work together
ye
study slide 3
ye
study slide 4
ye
describe the frontal lobe
frontal–prefrontal association cortex, develops until you’re 25; contains primary motor cortex; the “go” lobe–>tells you to move;
Surrounded by areas of “higher motor function”make the movement from the PMC more complex, can inhibit movement
Motor planning, take in the information and make movement based on that
- Broca’s speech area (motor, expressive)
- premotor/ supplementary
motor areas
frontal eye fields (scanning visual field)e.g. loud noise, eyes go right to the source of the noise automatically
May have implications in autism
- orbital cortex, olfactory tract
study pic on slie 7
ye
describe the parietal lobe/cortex
- primary somatosensory sensory cortex
- secondary and tertiary somatosensory cortices
- connection between receptive and expressive speech areas
- e.g. asked question respond
also involved in trackin movements (smooth pursuit); if someone lacks smooth pursiot they had a stroke in this area; also motor and sensory defects
describe the occipital lobe
- visual cortices: primary (17)—see one dimension, secondary (18)—see a few dimension, tertiary (19)—see 3D, estimate height, width, etc
- dorsal areas = where? (analysis of motions and spatial relations). May not be able to identify where objects are
- ventral areas = what? (analysis of form and colour) Can’t recognize what an object is or who someone is
study slide 8 and 9 pics
ye
describe the temporal lobe
contains Wernicke’s areas;
W’s area: understanding of speech and written langugae; sensory aspect;
arcuate fasciculus between WA and BA–>very big connections a very vulnerable spot in the brain
If someone says t repeat something and you can’tsomething wrong with the area of connection between wernicke and broca’s connections
Hard to name things (e.g. can you get me that…um…um…etc)
also functions in memory; memory (medial portions, including hippocampus) , facial/ color recognition
Why is memory not association (higher function)? –>emotion associated with memory (survival); need to remember who your parents are, what animal tried to eat you, etc
Not unique to humans
describe the insula
primary auditory cortex
taste (primary gustatory nucleus)
other visceral sensory—e.g. going “oh crap” when you realize you forgot to plug your car in overnight
social, emotions, limbic
tightly linked to vomiting centre
4.1 Define, and label a diagram to show the location of key cortical regions, including motor, sensory,
unimodal, and multimodal regions: (review: be able to label the four (five) lobes of the cerebral
cortex, describe the major functions or each lobe, and describe the major source of blood supply for each lobe)
a. sagittal and lateral fissures, central (Rolandic) sulcus
b. motor regions:
- primary motor cortex (precentral gyrus)
- unimodal motor regions: premotor & supplementary motor regions (paracentral lobule);
Broca’s area
c. sensory regions:
- primary somatosensory (postcentral gyrus), primary auditory, & primary visual cortices
- unimodal association areas (somatosensory, auditory, visual); Wernicke’s area
d. multimodal association cortices: cingulate gyrus, prefrontal cortex
ye
Although there is some individual variability, the human brain has some characteristic “lumps and bumps”, or what are properly called gyri (elevations) and sulci (depressions).
These sulci and gyri serve as important landmarks and boundaries for the localization of very different types of cortical functions, even within a given cortical lobe.
ye
what does the central sulcus separate?
frontal and parietal lobes; aka ROLANDIC FISSURE
what does the lateral sulcus separate?
frontal and parietal lobes from temporal lobes; AKA SYLVIAN FISSURE
what does a sulcus often represent?
a significant separation of cortical function:
eg: the central sulcus separates the primary motor cortex (in the frontal cortex) from the primary somatosensory cortex (in the parietal cortex)
what does a Rolandic fissue present as?
Kids that have seizures may have Rolandic epilepsy–>means seizures along the Rolandic fissue; distinct motor and sensory deficits; symptoms = lip smacking, hypersalivation (oral cavity affected by these seizures!!)
study slide 17
ye
study slide 18
ye
study slide 19
ye
broca’s area = expressive language; wernicke’s area = understand what was said with you
ye
what is the primary motor cortex?
a portion of the brain in the precentral gyrus which contains large excitatory neurons (UMN) which project to brainstem and spinal cord to execute movement on CONTRALATERAL side of body
contralateral = deccasates at brain stem (?) and controls the opposite site of the body
what are the unimodal association cortices in the frontal lobe?
- premotor and supplementary motor regions (motor planning)
- Broca’s area (expressive language)
what are the multimodal association cortices in the frontal lobe?
- cingulate gyrus (medial surface) – limbic - error detector
limbic systems usually medial and ventral- prefrontal cortex (lateral surface) – judgement, abstract
reasoning, cognition, eye movementstructure that makes you as an adult; youths have a less developed preofrontal cortex; development complete at 25
Two or more purposes
- prefrontal cortex (lateral surface) – judgement, abstract
study slide 20& 21
ye
what is the primary somatosensory cortex?
- located in the postcentral gyrus (parietal lobe)
- contains many small neurons which receives different
types of somatosensory information from the
CONTRALATERAL side of the body
- contains many small neurons which receives different
what are the uni- and multimodal cortices in the parietal lobe?
Unimodal & multimodal association somatosensory cortices:
- processes higher somatosensory information
- no specific regions of note, except that damage to these
cortices can cause neglect
Unimodal & multimodal areas are less defined
study slide 23
ye
what is the primary auditory cortex?
in temporal lobe;
what is wernicke’s area?
the area for processing the
receptive aspects of speech – sends information
to Broca’s area via a pathway called the arcuate
fasciculus
surrounds primary auditory cortex
the primary visual cortex in occipital lobe
ye
study slide 25
ye
where is the cingulate gyrus located?
on medial surface of the cortex
what is the paracentral lobule?
involved in:
Supplementary motor area: internally (not stimulus) driven movement–>planning or imagining movements
Primary motor cortex: legs and feet (can’t move legs and feet from stroke/issues on medial surface/inside of brain)
Primary somatosensory cortex: legs and feet
located on the medial surface of the cortex
KNOW SLIDE 28
YE
Broca sits in frontal because it is associated with motor usage; Wernik. Next to primary auditory cortex
ye
describe arterial supply of the brain
The ACA (anterior cerebral artery) supplies the medial portions of the cerebral cortex – legs and feet The MCA (middle cerebral artery) supplies the lateral portions of the cerebral cortex – arms, face, oral cavity
Broca stroke = difficulty chewing or speaking
Wernicke stroke = may not be able to understanding you and your instructionsmay want power of attourney
Describe:
- the role of primary, unimodal association, and multimodal association cortices in the processing of information
- the role played by associational and commissural fibers in the cerebral hemisphere
primary cortices are ground zero for the reception or the production of information (i.e., sensory or motor information); unimodal (aka secondary) cortices process “higher” information for one specific modality (such as planning simple motor behaviors, processing specific aspects of a sensation, etc.); multimodal association cortices: process information across all modalities (motor, sensory, limbic, cognitive)–aka “tertiary cortices”
study slide 39 & 40
ye
describe the unimodal sensory cortex
-receives its predominant input from primary sensory cortex of specific modality
feeling sharpness of an object, cold, etc
-performs higher-order sensory processing for that modality
a type of ASSOCIATION cortex
describe the unimodal motor cortex
- projects predominantly to primary motor cortex
- formulates the motor program for complex actions involving multiple joints
a type of ASSOCIATION cortex
what are association fibres/intrahemispheral fibres for?
Single modality of sensation
Responsible for:
Complex aspects of sensation
Compensation for missing
pieces of information
If someone has a stroke in this visual association area will lack the brain area to fill in the missing pieces
study slide 47
ye
describe the multimodal cortex
- located in the frontal lobes and parieto-occipital-temporal regions
- has bi-directional connections with BOTH motor and sensory association (unimodal) cortices
- has bi-directional connections with other cortical regions – including limbic system
- performs the highest-order mental functions
- integrates abstract motor and sensory info from associational cortices; puts together with the motivational and emotional influences from the limbic system (or “limbic cortex”)
can control stuff such as language processing and production (hearing, seeing, touching, and writing, and reading); arithmetic, abstract reasoning, socially appropriate behaviour, concentrating
Multiple modalities of sensation
Integration of:
Sensory information across modalities
Sensory with limbic information
what are the limbic cortical regions and what are they responsbile for?
- Cingulate gyrus; 2. orbital frontal cortex; 3. parahippocampal gyrus
MAAA:
Motivation
Assigning emotional
significance to sensory
information
Attending to relevant or
interesting stimuli
Add “emotional flavour”
to cognitive activities
what are the functions of multimodal cortices?
- arithmetic
- abstract reasoning
- language processing and production
- socially appropriate behaviour
- concentrating
