Lecture 2 Flashcards
primary auditory cortex location
temporal lobe, Brodmann area 41
primary auditory cortex function
detect sound (auditory input)
primary auditory cortex blood supply
inferior branch MCA
primary auditory cortex lesion
unilateral lesion = occur from tumor, stroke, or trauma and experience a small loss in the ability to detect sound
bilateral lesion = unable to detect sound known as central deafness or cortical deafness, VERY RARE
secondary auditory cortex function
recognize/distinguish different sounds (frequencies, pitch, etc.)
secondary auditory cortex location
temporal lobe, brodmann area 42
secondary auditory cortex blood supply
inferior branch MCA
secondary auditory cortex lesion
auditory agnosia = loss of the ability to recognize or distinguish sounds (frequencies, pitch, etc.)
associative auditory cortex location
posterior area 22 = non-dominant hemisphere
Wernicke’s area = dominant hemisphere
temporal lobe
dominant hemisphere associative auditory cortex function
interpret the linguistic component of verbal communication, linguistic - semantic content (words, sentences) of language
associative auditory cortex blood supply
inferior branch MCA
dominant hemisphere associative auditory cortex lesion
wernicke’s aphasia can’t comprehend but can speak, word salad
anterior cerebral artery ACA
supplies sagittal wall of frontal and parietal lobes
middle cerebral artery MCA
supplies the lateral hemisphere
posterior cerebral artery PCA
supplies occipital lobe and inferior temporal lobe
superior MCA
branches exit superiorly along Sylvian fissure
inferior MCA
branches exit inferiorly/posteriorly along Sylvian fissure
MCA vascular territory
supplies the lateral region of the cerebral hemispheres, “lateral portions” of frontal, parietal, and temporal lobes
superior MCA vascular territory
supplies lateral cerebral hemisphere (cortex) above Sylvian fissure (frontal/parietal lobes)
inferior MCA vascular territory
supplies lateral cerebral hemisphere below and posterior to Sylvian fissure (temporal/parietal lobes)
ACA pathway
runs anteriorly to the longitudinal fissure along medial surface cerebral hemisphere, ascends and circles back along cingulate gyrus off branches that continue to ascend along the medial surfaces of the hemispheres
ACA vascular territory
anterior medial surface of each hemisphere, terminal branches of ACA supply superior and anterior lateral surfaces of each hemisphere
PCA pathway
runs posterior along medial and inferior surfaces of each temporal lobe eventually wraps around to posterior surfaces of each hemispheres
PCA vascular territory
supplies inferior/medial temporal lobe and the occipital lobe
how many brodmann areas are there
52 distinct regions of the cerebral cortex
dominant vs non-dominant hemisphere
dominant indicates the hemisphere that contains the language loop
left hemisphere = dominant
right hemisphere = non-dominant
frontal lobe functions
motor movement
executive function (goal directed behavior)
emotions, self-awareness and motivation
social behavior
parietal lobe function
somatosensory perception
integration of auditory, visual & somatospatial information
understanding communication
thinking, analysis, directing attention
temporal lobe function
auditory perception/processing
plays role in understanding language
involved in long term memory and emotion
occipital lobe function
visual perception and processing
types of sensory input
auditory
visual
somatosensory
olfaction (smell) - inferior temporal lobes
gustatory (taste) - insular lobe
vestibular
organization of the sensory cortices
specialized areas of gray matter in the cortex detect, recognize and interpret to each sensory modality = auditory, visual, somatosensory, taste, olfaction, and vestibular
three steps in processing a sensory modality in the cortex
detect the sensory modality->recognize the characteristics of the sensory modality->interpret/give meaning to the sensory modality
primary sensory cortex
detects the sensory modality
secondary sensory cortex
recognizes the characteristics of the sensory modality
associative sensory cortex
interprets/gives meaning to the sensory modality
gnosia
ability to recognize and/or perceive sensory information
agnosia
loss of the ability to recognize and/or perceive sensory information
language processing
multisensory including auditory, visual, and somatosensory
angular and supramarginal gyri
areas 39 & 40, multimodal sensory processing area of language (auditory, visual, and somatosensory), the angular and supramarginal gyri have other associative functions
non-dominant posterior area 22 function
interpret the non-linguistic components of verbal communication, normal variations in intonation, tone/pitch, rhythm, stress, musical or emotional component of verbal communication
non-dominant posterior area 22 lesion
sensory dysprosodia = difficulty or inability to interpret normal speech intonation and stress patterns (tone, pitch, rythm, etc.) of verbal communication, patient can’t interpret musical or emotional components of verbal communication
prosody
patterns of stress and intonation in a language
primary and secondary visual cortex location
occipital lobe
visual sensory areas
what is it pathway?
where is it pathway?
primary visual cortex location
occipital lobe, brodmann area 17
primary visual cortex blood supply
PCA
primary visual cortex function
detect visual input
visual fields
all information from right visual field is processed by the left primary visual field, all the information from the left visual field is processed by the right primary visual field
primary visual cortex lesion
patient may experience cortical blindness
cortical blindness
inability to detect visual input (loss of vision) in the visual cortex affected
loss of area 17 in one hemisphere
contralateral homonymous hemianopia with macular sparring, one half of visual field except small central spot is lost in each eye, patient is unable to see in either the left or right visual field
secondary visual cortex location
occipital lobe, brodmann areas 18 and 19
secondary visual cortex blood supply
PCA
secondary visual cortex function
recognize and distinguish shape (form), color, spatial orientation and movement
secondary visual cortex lesion
visual agnosia = loss of the ability to recognize or distinguish shapes, forms, colors or spatial orientation and movement
agnosia
refers to a loss of the ability to recognize and/or perceive sensory information
color agnosia
is a form of visual agnosia, loss of the ability to recognize colors (stroke, tumor, or trauma)
color blindness
congential dysfunction of the rods/cones of the eye, inability to recognize colors
achromatopsia
congenital inability to perceive colors, complete - only perceive things in black, white, or shades of gray, incomplete - some color perception possible
visual association cortices
what is it? and where is it? pathways
visual association cortices pathways
parietal lobe - posterior/superior region of parietal lobe
temporal lobe - inferior surface of temporal lobe
visual association cortices blood supply
PCA
where is it pathway? location
parietal lobe, brodmann area 7
where is it pathway? function
spatial processing
where is it pathway? lesion
loss of the ability to recognize relationship “awareness” between location/movement of objects and the body
what is it pathway? location
temporal lobe, inferior surface aka fusiform gyrus
brodmann area 37
what is is pathway? function
object processing, recognizing faces and places, interprets face and complex 3D spatial forms (place) and plays role in encoding visual memory
what is it pathway? lesion
loss of the ability to “recognize faces & places”
prosopagnosia
prosopagnosia
loss of the ability to recognize and identify familiar faces
visual sensory areas clinical application - reading
requires ability to detect, recognize and interpret letter shapes, words and sentences
reading pathways of the brain
visual sensory areas and language processing areas - occipital, temporal, and parietal lobes
motor areas for speaking or writing - frontal lobe
dyslexia
difficulty in the ability in learning to fluently and accurately read or interpret words, letters, and other symbols
non-dyslexic individual
Inferior parietal lobe and Broca’s area process new words and will encode into temporal areas to encode for quick recognition and long-term memory
dyslexic individual
activity of inferior parietal lobe and temporal lobe are limited when reading and Broca’s area extremely active (compensates) to process words by connecting sounds with letters
primary somatosensory cortex location
parietal lobe, postcentral gyrus immediately posterior to central sulcus
Brodmann’s area 3,1,2
primary somatosensory cortex blood supply
superior branch MCA = face, UE, neck and upper trunk
ACA = lower trunk, LE
primary somatosensory cortex function
detect/localize somatosensory sensation from the contralateral side of the body, cortex is organized as HOMUNCULUS
lateral region of area 3,1,2
function = UE, head, neck
blood supply = MCA superior
medial region of area 3,1,2
function = LE/trunk
blood supply = ACA
primary somatosensory cortex lesion
contralateral hemianesthesia, loss of the ability to detect and localize somatosensory input (touch, proprioception, temperature, nociception) on OPPOSITE side of the body
anesthesia
inability to detect sensation
analgesia
inability to feel pain
secondary and associative somatosensory cortices location
parietal lobe, brodmann areas 40,5,7
secondary and associative somatosensory cortices blood supply
superior branch of MCA
secondary and associative somatosensory cortices function
recognize and interpret somatosensory characteristics, pleasant touch, pain, temperature, physical form/shape, contour, texture, movement of the body aka TACTILE PERCEPTION
secondary and associative somatosensory cortices lesion
astereognosis or agraphesthia
asterognosis
loss of the ability to judge the form of an object by touch
stereognosis
difficulty recognizing a familiar form (number/letter) traced on the area of skin
agraphesthesia
difficulty recognizing a familiar form (number/letter) traced on the area of skin
