Cerebral
cortex presents functionally specialized areas. For the descriptive purpose, these areas can be located on different lobes of cerebral hemisphere as given below:
Frontal lobe
Parietal lobe
2. Secondary
somesthetic area
Occipital lobe
Temporal Lobe
Frontal lobe
1. Motor
area or Primary motor area
Broadmann’s area 4
Broadmann’s area 4
- Precentral gyrus and anterior part of
paracentral lobule
- Produce isolated movements on the opposite
side of the body
- Somatotopic representation
o
Inverted and disproportionate to the
size of the body part
o
lips, tongue, face, and hands are
represented in order on the lower lateral surface
o
arm, trunk, and hip in order on the
upper lateral surface
o foot, lower leg and anal and genital region on
paracentral lobule on medial surface
- 2. Premotor area or secondary motor area
Broadmann’s area 6 and parts of area 8, 44, and 45
Broadmann’s area 6 and parts of area 8, 44, and 45
- Anterior part of precentral gyrus and
posterior part of superior, middle and inferior frontal gyri
3. Supplementary
motor area
-
Medial frontal gyrus on the medial
surface
4. Frontal
Eye Field
-
Broadmann’s area 8
-
Lies in the middle frontal gyrus in
front of precentral gyrus
-
Causes both eyes to move to opposite
side
5. Motor
Speech area of Broca or Broca’s area
-
Broadman’s area 44 and 45 on the
dominant hemisphere
-
Located in the inferior frontal gyrus
(pars triangularis and pars opercularis)
-
Injury results in aphasia (inability to
speak)
6. Prefrontal
cortex
-
Anterior to precentral area
o
Most of the part of frontal gyri;
orbital gyri, most of medial frontal gyrus and anterior part of cingulated
gyrus
o
Broadmann’s area 9, 10, 11 and 12
-
This area is concerned with
o
normal expression of emotions
o
ability to predict consequences of
action
Parietal lobe
1. Primary
somesthetic area
-
Broadmann’s area 3,1 and 2
-
Occupies precentral gyrus and posterior
part of paracentral lobule
-
Receives fibers from ventral posterior
lateral and ventral posterior medial nuclei of thalamus
-
Somatotopic representation
o
Inverted and disproportionate to the
size of the body part
o
lips, tongue, face, and hands are
represented in order on the lower lateral surface
o
arm, trunk, and hip in order on the
upper lateral surface
o
foot, lower leg and anal and genital
regions on paracentral lobule on
medial surface
-
Superior lip of posterior ramus of
lateral sulcus
3. Somesthetic
association area
-
Broadmann’s area 5 and 7
-
Occupies superior parietal lobule
extending onto the medial surface
-
Extensive connection with other sensory
areas of cortex
-
Receive and integrate different sensory
modalities
-
Enables one to recognize object placed
in the hand without visual aid
Occipital lobe
Primary visual area
-
Broadmann’s area 17
-
Walls of the posterior part of the
calcarine sulcus
-
Receives fibers from lateral geniculate
body
Secondary visual area
-
Broadmann’s areas 18 and 19
-
Surrounds the primary visual area
-
Interpret and relate the visual
information received by primary visual area
Temporal Lobe
Primary auditory area
-
Broadmann’s areas 41 and 42
- Situated in the inferior wall of
posterior ramus of lateral sulcus
Secondary auditory area
-
Broadmann’s area 22
-
Posterior to primary auditory area in
the lateral sulcus and in the superior temporal gyrus
Sensory speech area of Wernicke
-
Present in the dominant hemisphere
-
In the superior temporal gyrus with
extensions around posterior end of lateral sulcus
-
Connected to Broca’s area by arcuate
fasciculus
-
Receives fibers from visual and auditory
cortex
-
Enables understanding of written and
spoken language
REFERENCES:
Gray’s Anatomy, 39th Edition
Snell’s Clinical Neuroanatomy 7th Edition
Lange Clinical Neuroanatomy 25th Edition
Gray’s Anatomy, 39th Edition
Snell’s Clinical Neuroanatomy 7th Edition
Lange Clinical Neuroanatomy 25th Edition