Functional areas of the cerebral cortex

1. FUNCTIONAL ANATOMY OF
THE CEREBRAL HEMISPHERES
Dr.Mohammed Sadiq Azam
Postgraduate, Prof.Siraj’s unit, M:I
Deccan College of Medical Sciences

2. BRAIN - ANATOMY

3. BRAIN - ANATOMY

4. BRAIN - ANATOMY

5. BRAIN – FUNCTIONAL ANATOMY

6. HISTOLOGY
Six layers:
I: Molecular layer
II: External granular layer
III: Small pyramidal cell layer
IV: Internal granular layer
V: Large pyramidal cell layer
VI: Layer of fusiform or
polymorphic cells

7. SOMATOSENSORY CORTEX

8. SENSORY HOMUNCULOUS

9. SOMATOSENSORY CORTEX
• SSA 1 & SSA 2
• Amorphsynthesis – forgets one half

10. MOTOR CORTEX

11. MOTOR HOMUNCULOUS

12. MOTOR AREAS

13. ROLE OF BRAIN STEM IN MOTOR
FUNCTION:
• Way station for “command signals”
• Important in movement & equilibrium
• Reticular nuclei and vestibular nuclei
• Vestibular nuclei: M, K, S

14. VISUAL CORTEX

15. VISUAL CORTEX

16. VISUAL CORTEX

17. CONTROL OF EYE MOVEMENTS
• EOM:
• Medial & Lateral recti
• Inferior & Suerior recti
• Superior & Inferipr oblique
• MLF

18. CONTROL OF EYE MOVEMENTS
• Fixation eye movements
• Voluntary fixation mechanism
• Involuntary fixation mechanism
• Role of superior colliculi in involuntary fixation
• Continuous tremor
• Slow drift
• Flicking movts
• Saccadic eye movements
• Pursuit movements

19. AUDITORY
CORTEX

20. AUDITORY CORTEX
• Determination of direction of entry of sound:
• Time lag between entry of sound into one ear and the other
• Difference between the intensities of the sounds in the two
ears.
• Neural mechanism:
• Superior olivary nucleus

21. OLFACTORY CORTEX
• Very old – Medial olfactory area
• Hypothalamus & limbic cortex
• Less old olfactory area
• Limbic cortex & Paleocortex
• Newer pathway
• Dorsomedial thalamic nucleus
• Lateropasterior quadrant of the orbitofrontale cortex

22. ASSOCIATION AREAS

23. ASSOCIATION AREAS
• Parietooccipitotemporal association area:
• Spatial co-ordinates
• Language comprehension (Wernicke’s area)
• Visual comprehension (Angulate gyrus - Dyslexia)
• Naming objects
• Prefrontal association area:
• Sequential and parallel inputs of motor function
• Planning of motor activity (thought process)
• Working memory

24. ASSOCIATION AREAS

25. WERNICKE’S AREA:
• = GENERAL INTERPRETIVE AREA
• = GNOSTIC AREA
• = KNOWING AREA
• = TERITARY ASSOCIATION AREA
• Single greatest role of any part of the cerebral cortex
for the function of intelligence.
• Highly developed on the dominant hemisphere in the
posterior part of the superior temporal lobe.

26. ANGULAR GYRUS
• Most inferior portion of posterior parietal lobe.
• Visual comprehension
• Dyslexia

27. FACE RECOGNITION
• Medial undersides of both occipital lobes
• Prosophenosia

28. SPEAKING A HEARD WORD

29. SPEAKING A WRITTEN WORD

30. NON DOMINANT HEMISPHERE
• Interpretation of music
• Nonverbal visual experiences (patterns)
• Spatial relationships between person and environment
• Body language, intonation of voices
• Somatic experiences from limbs and hands

31. Gerstmann syndrome
• Lesion at angular and supramarginal gyri near
parietotemporal junction
• Dysgraphia
• Dyscalculia
• Finger agnosia
• Left right disorientation

32. THANK YOU