FUNCTIONAL AREAS OF THE CEREBRAL CORTEX.pptx

FUNCTIONAL AREAS OF THE CEREBRAL CORTEX

1. FUNCTIONAL AREAS OF THE CEREBRAL CORTEX Mrs.MANJULA.S ASST PROF, VISTAS

2. The cerebral cortex is the outermost layer of the brain and is responsible for many higher cognitive functions. The cerebral cortex is divided into several functional areas, each associated with specific functions. Cerebral cortex is responsible for the higher-level processes of the human brain, including language, memory, reasoning, thought, learning, decision-making, emotion, intelligence and personality. The functional areas can be broadly categorized into four lobes: frontal, parietal, temporal, and occipital. Cerebral cortex

3. Lobes of the Cerebrum The lobes can be broadly categorized into four types: frontal, parietal, temporal, and occipital.

4. The cerebral cortex was originally classified by Brodmann into 52 different areas, which are referred to as Brodmann’s areas. Not all of these areas anatomically correlate to function. Few of the following are IMPORTANT: Motor cortex (Brodmann’s areas 4, 6 and 8) The primary somatosensory cortex corresponding to Brodmann’s areas 3, 1 and 2 Secondary sensory cortex (Brodmann’s areas 5 and 7) Visual cortex (Brodmann’s areas 17, 18 and 19) Auditory cortex (Brodmann’s areas 41 and 42) Brodmann’s areas

5. Primary motor cortex is located in the precentral gyrus  of the frontal lobe (Brodmann’s area 4) and is essential for the execution of voluntary movement. . It contains anterior two-thirds of the paracentral lobule. Secondary motor cortex that consists of the four regions: Supplementary motor cortex The premotor cortex The frontal eye field The posterior parietal motor area Motor cortex

6. Rostrally to the inferior part of the primary motor cortex, motor speech area ( Broca area) is located. It is placed within the part of the inferior frontal gyrus and is represented with Brodmann's area 44 and 45, and with the most human brains, it is located within the left hemisphere. Lesions of this area cause motor aphasia.   The  premotor area (Brodmann’s area 6) strips rostrally to the primary motor area on the lateral surface of the hemisphere. Part of this area is located on the medial surface of the hemisphere, and that part is called supplementary area . The premotor cortex is essential for planning of the movements. It sends that information to the primary motor cortex, which then starts the execution of the movement.   The frontal eye field is placed in the posterior part of the medial frontal gyrus ( Brodmann’s area 8). It has a significant role in the movements of the eye bulb. Motor cortex

7. The sensory cortex contains several very important areas: Primary somatosensory area Secondary somatosensory field Primary visual field Secondary visual field Primary acoustic field Primary olfactory fields Primary gustatory field Primary vestibular field Primary somatosensory area (Brodmann’s 3, 1, 2) is placed within the most of the  postcentral   gyrus  and last third of the paracentral lobule. The secondary somatosensory area is placed rostrally to the central sulcus , along with its edge. The sensory fibers that conduct  nociceptive  sensibility (pain) end here.   Sensory cortex

8. Primary visual area (Brodmann’s area 17 and 16) is placed within the medial aspect of the occipital lobe, and surrounds the calcarine fissure. The neurons of the optical pathway end here.  Secondary visual areas (Brodmann’s area 18 and 19) are responsible for identification and understanding of the properties of the observed object. Primary acoustic area (Brodmann's area 41 and 42) is placed in the superior side of the superior temporal gyrus , called as Heschl gyri . The primary olfactory area is placed within the piriform cortex that is located between the insula and the temporal lobe. Also, the prepiriform cortex is the part of the primary olfactory area, and it is found between the lateral olfactory tract and the temporal cortex. The primary gustatory area is placed within the most inferior parts of the postcentral gyrus and adjacent parts of the insula . The primary vestibular area is thought to be in superior temporal gyrus . Sensory cortex

9. One of the most important associative areas is found on the mutual border of the parietal, occipital and temporal lobe. This area contains the  supramarginal gyrus  (Brodmann’s area 40), the angular  gyrus  (Brodmann’s area 39) and the posterior part of the superior temporal gyrus  (Brodmann’s area 22 - Wernicke field). This cortical area is specifically important for the processes of speech, reading, writing and visual orientation. Associative cortex

10. On the inferior surface of the temporal lobe, specifically within the lateral occipito temporal gyrus , is the area for the face recognition. If a patient is suffering from a lesion of this area, they are unable to recognize the faces.   The  prefrontal associative area extends through the biggest portion of the frontal lobe (Brodmann’s areas 8, 9, 10, 11, 12, 45 and 46), and it takes up to 25% of the entire cortical surface. This area is divided into lateral, medial and ventral ( orbito frontal) part. This entire area is essential for cognitive thinking, judgment, motivation, emotions, and planning of the behavior. Associative cortex