1. The Brain

2. Nervous System Nervous System contains:
Brain, cranial nerves, spinal cord, spinal nerves, and peripheral nerves
Function: coordinate and regulate the body’s responses

3. Basic Unit of the nervous system is a neuron
Structure
Dendrites – transmits impulses TO the cell
Axon – transmits impulses AWAY from cell
Function: cause body to react to its environment

4. 2 types of neurons Sensory: in the skin and sensory organs
Sends impulses from organs to the brain
Motor: originate in brain & spinal cord
Carries impulses to muscles and glands
Example:
Sensory detects heat
Motor causes the body to move away

5. Central Nervous System (CNS) Brain
Consists of the brain and spinal cord
Brain
Controls and coordinates body activities
Weighs about 3 lbs
Requires Oxygen and sugar to perform at its highest potential

6. The brain is surrounded by a protective barrier of membranes called the meninges
3 layers
Innermost layer contains many blood vessels to “feed” the brain
Between each layer is space

7. Brain has 4 hollow spaces (ventricles)
Constantly produce Cerebrospinal Fluid
Clear, colorless, watery fluid
Flows through brain and spinal cord
Provides protection and shock absorber
Provides nourishment and removes different waste products
Eventually becomes absorbed by veins

8. Parts of the Brain Brain consists of different parts: Cerebrum
Cerebellum
Brainstem
Pons
Medulla Oblongata
Midbrain

9. Cerebrum Controls willful actions sensory messages
Governs thought and speech
Largest Part
2 halves (right and left)
2 layers: gray matter – outer, white matter - inner

11. Cerebellum Responsible for muscle coordination
Tone, balance, and posture

12. Brainstem Midbrain Pons Medulla Oblongata
Conducting impulses throughout brain
Conduction of visual and auditory reflexes
Pons
Bridge between sections of brain
Some reflex actions such as chewing and salivation
Medulla Oblongata
Controls involuntary actions
Respiration, blood pressure, heartbeat, swallowing

13. Spinal Cord
Function: conduct impulses (sends message) connect body parts to brain
Protected by vertebrae, CSF, & meninges

14. Vocab Words
CSF
Meninges
CNS
Cerebrum
Cerebellum
Brainstem