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1. Gawad
Neuroscience Physiology
Lecture 8
Wednesday, November 14, 2018 1

4. • Somatosensory cortical areas site:
• located in the parietal lobe and include:
• (1) The primary somatic sensory areas I and II.
• (2) The secondary somatic sensory (or association) area.

5. 1- Somatosensory area I:

6. 1- Somatosensory area I:
● Site:
- postcentral gyrus (Brodman's areas 1, 2 and 3).

7. 1- Somatosensory area I:
● Site:
- postcentral gyrus (Brodman's areas 1, 2 and 3).

8. 1- Somatosensory area I:
● Site:
- postcentral gyrus (Brodman's areas 1, 2 and 3).

9. 1- Somatosensory area I:
● Characters:
It receives sensations from the opposite side of the body.
Due to decussation of ascending pathways

10. 1- Somatosensory area I:
● Characters:

11. 1- Somatosensory area I:
● Characters:

12. 1- Somatosensory area I:
● Characters:
face
hand
arm
trunk
mech
nical
Temp Pain
modality separation of
different sensations

13. 1- Somatosensory area I:

14. 2- Somatosensory area II:
pain intensity
tactile learning and tactile memory
poorly localized.
less sharp

15. (B) Somatic sensory association area ((Posterior
parietal cortex, Brodman's areas 5 and 7):

16. Motor Cortex

19. I- Primary motor area (area 4)
precentral gyrus
in the frontal
lobe

20. I- Primary motor area (area 4)
representation of any part of
the body is directly
proportional to the
complexity of its function
not to its size

21. I- Primary motor area (area 4)
• Stimulation of small regions of primary motor cortex elicits
movements that require the activity of numerous muscles.
• It contains large pyramidal cells called Betz cells
• Lowest intensity stimulation can elicit movements.
It is an area of high excitability

22. II- Premotor area 6

23. II- Premotor area 6
It is an area of low excitability

24. III- Supplementary motor area
on the medial surface of the frontal lobe

25. III- Supplementary motor area
less excitable than area 4

26. Specialized area that control specific movements,

27. Broca's area (area 44):
Lies anterior to the lower part of area 4, it is essential for speech.

28. Eve movement area (frontal eve field area or area 8):
Lies above the Broca's area, concerned with conjugate movement of the eye toward
different objects, and autonomic eye effects such as lacrimation.

29. Area of hand skills (Exner`s area)
Lies anterior to the primary motor area. It is essential for skilled movements of the hands.
motor apraxia

30. I- Prefrontal association area

31. II- Parieto occiptio temporal association area
This area is located between the somatosensory cortex anteriorly, visual cortex
posteriorly and auditory cortex laterally.

32. Wernick’s area
Area 39 in the angular gyrus

33. III. The Limbic association area: