brain functional areas Flashcards
B 4
Primary motor cortex
L: Precentral gyrus extending into anterior part of paracentral lobule
F:execution of distinct, well defined voluntary movements on the contralateral side
Lesion:produce paralysis of the extremities of the opposite half
B 6 (lateral aspect)
Premotor cortex
L: anterior part of the precentral gyrus & posterior part of superior, middle and inferior frontal gyri.
F:programming of complex motor activity, which then relayed to primary motor cortex
LESION:difficulty performing skilled movements.
6
(B6 Medial surface)
Supplementary motor area
F:preparatory role in programming complex sequences of movement.
“Motor Association Cortex”
areas 6, 8, 44, and 45.
involved in movement throughout the body, including motor speech movements.
B 6, 8 & 9
Frontal eye field
L:Extends forward from the facial area of the precentral gyrus into the middle frontal gyrus
F:conjugate movements of the eyes,scanning movements of the eyeball
LESION: two eyes to deviate to the side of
lesion and an inability to turn the eyes to the
opposite side.
B 9, 10, 11, and 12.
Prefrontal cortex
L:greater parts of the superior, middle, and inferior frontal gyri; the orbital gyri; most of the medial frontal gyrus; and the anterior half of the cingulate gyrus
F:individual’s personality, depth of
emotions, social, moral & ethical awareness, judgement, abstract thinking
LESION:clownish behaviour, euphoric, vulgar speech
Motor speech (Broca)
Pars triangularis-45 & pars opercularis- 44 of inferior frontal gyrus of the frontal lobe of Dominant hemisphere
F:Production of expressive speech / Vocalization. Formation of words with connections to adjacent primary motor area.
LESION:Motor aphasia. Agrammatical & nonfluent speech. Expressive aphasia.
B 3,1,2
Primary somatosensory area
L: Postcentral gyrus, extend to posterior part of the paracentral lobule on the medial surface.
F perception of exteroceptive & proprioceptive sensations from opposite half of the body.
Lesion:altered sensations on the opposite side of the body. Sensation of crude pain, touch and temperature return(believed to be due to the functions
of thalamus).
B 5, 7
Somatosensory association area
L: superior parietal lobule
F:Receives and interprets different sensory modalities which help in stereognosis
B17
Primary visual (striate) cortex
L: medial surface of occipital lobe on banks of calcarine fissure, extend into posterolateral surface
F: visual input from contralateral visual field - fibres of optic radiation from lateral geniculate nucleus
Lesion: contralateral homonymous hemianopia.
B18 & B19
Visual association areas
L:Surround primary visual cortex on medial & lateral surface
F:
– identifying object
– determining its location, colour & significance
– comparing with prior visual
experience
B41 & 42
Primary auditory cortex
L:anterior transverse temporal gyrus (Heschl’s gyrus) on the upper surface of superior temporal gyrus
F: Receives auditory radiation from medial geniculate nucleus (MGN)
anterior part:reception of sounds of low frequency
posterior part: sounds of high frequency
B 22
SECONDARY auditory cortical areas
L:Surround primary auditory cortex
F: * interpretation of sound
* comprehension of language via connection
with Wernicke area
Sensory speech (Wernicke) area
Consist of
➢auditory association cortex (part of B 22)
➢parts of supramarginal & angular gyri (B 39 & 40)
*in dominant hemisphere
* connected to Broca area by arcuate fasciculus
F:important role in comprehension & formulation of language
LESION: loss of ability to understand the spoken or written words – RECEPTIVE APHASIA./SENSORY APHASIA
