1. CNS General Structure Composed of brain and spinal cord
Brain enclosed in skull and surrounded by a tough three-layer membrane called meninges
The meninges forms the blood brain barrier – determines what chemicals reach the brain

3. Cerebrospinal Fluid
Circulates between two layers in the meninges and also in spinal cord
Functions:
Shock absorber
Transport medium
Spinal Tap – extraction of cerebrospinal fluid to diagnose infection

5. Spinal Cord
Carries sensory nerve messages to the brain and motor nerve messages from the brain to effectors
Emerges from skull through opening called foramen magnum and extends down through canal in backbone

6. Spinal Cord Organization
Two types of nerve tissue
White matter – myelinated nerve fibres from sensory and motor neurons
Grey matter – nonmyelinated interneurons
Interneurons form nerve tracts that connect spinal cord with brain
Dorsal nerve tract – sensory info into spinal cord
Ventral nerve tract – motor info from spinal cord to effectors

9. The Brain

11. Brain Structure
Three distinct regions: forebrain, midbrain and hindbrain
Forebrain contains:
Olfactory lobes – receive info about smell
Cerebrum – major coordinating centre
Two hemispheres
Contain regions associated with speech, reasoning, memory, and other higher functions
Surface called cerebral cortex – made of grey matter with many folds to increase surface area

12. Lobes of the Cerebrum Cerebral cortex divided into parts called lobes:
the frontal lobe
the parietal lobe
the temporal lobe
the occipital lobe

13. The frontal lobe is the center for voluntary movement
is called the “motor area” (movement)
includes the prefrontal area,
for intelligence, creativity, memory, and personality.

14. The parietal lobe Collects, recognizes, and organizes sensations:
feelings of
pain
temperature
touch
position
movement

15. The temporal lobe processes auditory (hearing) information
stores auditory (hearing) and visual (seeing) memories

16. The occipital lobe is at the back of the cerebral hemisphere involves
vision
visual memory
eye movements

18. Cerebral Hemispheres
Two cerebral hemispheres are not mirror images of each other
Right side associated with visual patterns or spatial awareness
Left side linked to verbal skills
Some people may have one side more dominant which may affect the way they learn
Corpus callosum – bundle of nerve fibres connecting two hemispheres

21. Midbrain Less developed than forebrain
Consists of four spheres of grey matter
Mostly composed of tracts of nerve fibers
Relay centre for some eye and ear reflexes

22. Hindbrain Joins to spinal cord Major regions: Cerebellum Pons
Largest section of hindbrain
Controls limb movements and balance
Pons
Relay station passes info between two regions of cerebellum
Medulla oblongata
Controls involuntary muscle action (breathing movements, heart rate, etc)