1. Regions of the Brain Cerebral hemispheres Diencephalon Brain stem
Cerebellum
Figure 7.12
Slide 7.36

2. Cerebral Hemispheres (Cerebrum)
Paired (left and right) superior parts of the brain
Include more than half of the brain mass
Figure 7.13a
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3. Cerebral Hemispheres (Cerebrum)
The surface is made of ridges (gyri) and grooves (sulci)
Figure 7.13a
Slide 7.38

4. Lobes of the Cerebrum
Fissures (deep grooves) divide the cerebrum into lobes
Surface lobes of the cerebrum
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Slide 7.39

5. Lobes of the Cerebrum
Figure 7.15a
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6. Specialized Areas of the Cerebrum
Primary Sensory Area
Parietal lobe- POST-CENTRAL GYRUS
Somatic sensory area
Receives impulses from the body’s sensory receptors- pain, coldness or light touch
Primary Motor Area
Parietal lobe- PRE-CENTRAL GYRUS
Sends impulses to skeletal muscles
**The left side of the cortex receives impulses from right side, and vice versa. (fold hands)
Slide 7.41

7. Sensory and Motor Areas of the Cerebral Cortex
**The areas with the most sensory receptors or finest motor control have largest area of cortex
Figure 7.14
Slide 7.42

8. Specialized Area of the Cerebrum
Broca’s Area
Frontal lobe, base of pre-central gyrus
Involved in ability to speak
Injury to area- Inability to say words properly
Wernicke’s Area
Junction of temporal, parietal, occipital lobes
Language comprehension (word meanings)
Injury to area- “Word salad,” normal rhythm
Slide 7.43

9. Specialized Area of the Cerebrum
Cerebral areas involved in special senses
Gustatory area (taste)- lateral parietal lobe
Visual area- posterior occipital lobe
Auditory area- temporal lobe
Olfactory area (smell)- deep temporal lobe
Interpretation areas of the cerebrum
Language comprehension region- frontal lobe
General interpretation area- anterior frontal lobe
Slide 7.44

10. Specialized Area of the Cerebrum
Figure 7.13c
Slide 7.45

11. Layers of the Cerebrum Gray matter Outer layer
Composed mostly of neuron cell bodies
Figure 7.13a
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12. Layers of the Cerebrum White matter
Fiber tracts inside the gray matter
Example: corpus callosum connects hemispheres, allows communication
Figure 7.13a
Slide 7.47

13. Layers of the Cerebrum Basal nuclei –
internal islands of gray matter deep in white
Regulate voluntary motor activities
Injury- Huntington’s and Parkinson’s
Figure 7.13a
Slide 7.48

14. Diencephalon Sits on top of the brain stem
Enclosed by the cerebral heispheres
Made of three parts
Thalamus
Hypothalamus
Epithalamus
Slide 7.49

15. Diencephalon
Figure 7.15
Slide 7.50

16. Structures of Diencephalon
Thalamus
Surrounds the third ventricle
The relay station for sensory impulses, “crude” recognition of sensation
Transfers impulses to the correct part of the cortex for localization and interpretation
Slide 7.51

17. Structures of Diencephalon
Hypothalamus
Under the thalamus
Important autonomic n.s. center
Helps regulate body temperature
Controls water balance
Regulates metabolism
Center for many drives and emotions (part of “limbic system”
Regulates pituitary gland
Slide 7.52

18. Structures of Diencephalon
Mammillary bodies
Bulge from floor of hypothalamus
Reflex centers involved in smell
Pituitary gland
Attached to the hypothalamus
2 lobes- important hormones (including growth hormones)
Slide 7.53

19. Structures of Diencephalon
Epithalamus
Forms the roof of the third ventricle
Houses the pineal body (an endocrine gland)
Includes the choroid plexus – forms cerebrospinal fluid
Slide 7.54

20. Structures of Brain Stem
Attaches to the spinal cord- 3 in. long
3 areas: midbrain, pons, medulla
Pathway for ascending and descending tracts
Small gray matter areas:
form cranial nerves
control breathing, blood pressure
Slide 7.55

21. Brain Stem
Figure 7.15a
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22. Structures of Brain Stem
Midbrain
Mostly composed of tracts of nerve fibers
Has two bulging fiber tracts – cerebral peduncles (convey impulses)
Has four rounded protrusions – corpora quadrigemina
Reflex centers for vision and hearing
Slide 7.57

23. Structures of Brain Stem
Pons
The bulging center part of the brain stem
Mostly composed of fiber tracts
Includes nuclei involved in the control of breathing
Slide 58

24. Brain Stem- Medulla Oblongata
The lowest part of the brain stem
Merges into the spinal cord
Includes important fiber tracts
Contains important control centers
Heart rate control
Blood pressure regulation
Breathing
Swallowing
Vomiting
Slide 7.59

25. Structures of Brain Stem
Reticular Formation
Diffuse mass of gray matter along the brain stem
Involved in motor control of visceral organs
Reticular activating system plays a role in awake/sleep cycles and consciousness
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26. Reticular Formation
Figure 7.15b
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27. Cerebellum Two hemispheres with convoluted surfaces
Provides involuntary coordination of body movements
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28. Cerebellum
Figure 7.15a
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