1. Protection of CNS 1

2. The Brain 3 lbs About the size of two fists Wrinkled
Not solid- kind of mushy to the touch
Highly vasculated

3. Blood supply & Nutrition
Brain is highly vascular
blood delivers O2 and glucose supply and carries away wastes
Brain cells have no capacity for anaerobic respiration. They cannot be O2 deprived
Brain cells die w/in 5-6 minutes 3

4. Protection 1. Bone 2. Meninges 3. Cerebrospinal fluid (CSF)
Cranial bones & vertebral arches
2. Meninges
Dura mater
Arachnoid mater
Pia mater
3. Cerebrospinal fluid (CSF) 4

5. Meninges 3 Layers Dura mater (made of two membranes) Arachnoid mater
Pia mater 5

6. Dura Mater “Tough Mother” Thick, leathery outer covering
Support, and forms sinus system (where blood drains and returns to the heart)
Pain sensitive
Has own blood supply –
Middle meningeal artery
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7. Dura Mater
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8. Arachnoid Spongy/fibrous layer between the dura and pia
connective tissue
forms projections which give it a spider-web appearance
Forms Subarachnoid space
Contains CSF
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9. Pia Mater Innermost layer
Adheres almost indistinguishably to cortical surface, including sulci and gyri
Difficult to see grossly or remove
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10. 3 Layers of Meninges
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11. Cerebrospinal Fluid Produced from blood plasma in choroid plexuses
Located in the subarachnoid space
Cushions CNS - like waterbed
Nourishes brain tissue

12. Cerebrospinal Fluid
Returned to blood at superior sagittal sinus

13. Blood-brain barrier
Capillaries in the choroid plexus have thicker walls (than capillaries found elsewhere).
This means less molecules can passively diffuse into the CSF
Most molecules must be actively transported (therefore, they are “selected” to enter)
Protects brain from drugs, metabolites, toxins
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14. Ventricles of the Brain
2 Lateral ventricles (1, 2) in cerebral hemispheres
Third ventricle (3) between hemispheres (under the fornix)
Cerebral aquaduct connects the 3rd and 4th
Fourth ventricle (4) in midbrain and medulla 14

15. 4 Major Regions of the Brain
Anatomy of the Brain
4 Major Regions of the Brain

16. 1. Cerebrum or Cerebral Hemisphere
1. Cerebral Hemispheres (Cerebrum)
Paired superior parts of the brain
Largest part: includes more than half of the brain mass

17. The surface is made of ridges (gyri or 1 gyrus) and grooves (sulci or 1 sulcus)
Deeper grooves called fissures exist
Longitudinal fissure: separates the right and left hemisphere of the cerebrum

18. Cerebrum 4 Lobes of the cerebrum (on each hemisphere)
Lobes are named based on the cranial bones that lie over them
Surface lobes of the cerebrum
1. Frontal lobe
2. Parietal lobe
3. Occipital lobe
4. Temporal lobe
Central sulcus
Lateral sulcus
*Parietooccipital
sulcus

19. Specialized areas of the Cerebrum
Cerebral Cortex:
outer layer of the cerebrum (grey matter/cell bodies)
Processing of information occurs here
Labeled A
There are also “islands” of grey matter known as basal nuclei
*label B shows white matter/ neural axons- relaying of information occurs here

20. Cerebrum Corpus callosum connects the two cerebral hemispheres
It is a nerve tract (bundle of nerves having the same origin and destination)
Necessary for communication between the two
Labotomy is a procedure that cuts the corpus collasum

21. Cerebrum: Cerebral Cortex
(right side controls left side- vice versa)
Postcentral gyrus
Primary somatic sensory area:
receives impulses from the body’s sensory receptors (pain, cold, etc)
Precentral gyrus
Primary motor area
Sends impulses to consciously move skeletal muscles
Premotor area
Stores sequence activities

22. Cerebrum: Cerebral Cortex: Frontal Lobe
Association cortex:
involved in planning planning, complex ideas, behaviors, concentratio, ability to focus, emotional traits, judgment and inhibition
Broca’s area:
Involved in our ability to speak
Asymmetric (only on left hemisphere)

23. Cerebrum: Cerebral Cortex: Parietal Lobe
Association cortex:
receive and utilize information from the lower levels of the brain: temperature, taste, touch, and movement from the rest of the body – such as distance and position of objects

24. Cerebrum: Cerebral Cortex: Temporal Lobe
Important for making new memories, and for short-term memory, including memories of taste, sound, sight, and touch
Wernicke’s Area
responsible for receiving auditory information and recognizing words; it is thus central to the process of learning and understanding language.

25. Cerebrum: Cerebral Cortex: Occipital Lobe
primary visual center of the brain, processes information from the eyes, and links that information with images stored in memory.
In other words, this area helps you determine what you are looking at.

26. Regions of the Brain: 2. Diencephalon
Sits on top of the brain stem
Enclosed by the cerebral hemispheres
Made of three parts
(shown in yellow on brain model)
Thalamus
Hypothalamus (posterior to optic chiasma)
3. Epithalamus

27. Diencephalon Thalamus The relay station for sensory impulses
Transfers impulses to the correct part of the cerebral cortex for localization and interpretation

28. Regions of the Brain: Diencephalon
2. Hypothalamus (posterior to optic chiasma)
stimulates and controls structures such as the heart, most glands and smooth muscles
allows your systems to excite and relax, as needed. Examples:
Regulate body temperature
Controls water balance
Regulates metabolism
Drive/emotion, sex, appetite, thirst

29. Regions of the Brain: Diencephalon
Hypothalamus
The pituitary gland is attached to the hypothalamus

30. Diencephalon Epithalamus Location of pineal body
primarily responsible for melatonin cycles
Includes the choroid plexus
bundle of capillaries that form cerebrospinal fluid

31. 3. Brain Stem Attaches to the spinal cord Parts of the brain stem
A. Midbrain
B. Pons
C. Medulla oblongata

32. Brain Stem A. Midbrain Tracts of nerve fibers
Reflex centers for vision and hearing
Send messages to and from cerebrum
Connect the third and fourth ventricles- cerebral aquaduct

33. Brain Stem B. Pons The bulging center part of the brain stem
Mostly composed of fiber tracts
Controls breathing

34. Brain Stem C. Medulla Oblongata The lowest part of the brain stem
Merges into the spinal cord
Involuntary control center
Heart rate control
Blood pressure regulation
Breathing/Coughing
Swallowing/Gagging
Vomiting

35. 4. Cerebellum
Two hemispheres with convoluted surfaces (like the cerebrum)
Provides involuntary coordination of body movements (fine motor skills and smooth movements)
Balance/Coordination
Monitors body position