1. Divisions of the Nervous System

2. Central Nervous System
CNS– relays messages, processes information, and analyses information
The two parts are
Brain
Spinal Cord

3. Outer Protection of CNS
Meninges- three layers of connective tissue that surround the brain and spinal cord
Cerebrospinal fluid- fluid surrounding the brain that acts as a cushion.
Spinal tap – samples cerebrospinal fluid to test for bacteria or protein

4. Parts of the Brain Cerebrum Largest portion of the brain
The wrinkles increase the surface area which increases the number of neurons
Contains areas of higher reasoning and sensory interpretation

5. Parts of the Brain Cerebrum con’t
The left half analyzes the information from the right side of the body and vice versa.
Made of two layers
Grey matter – tightly packed cell bodies
White matter – tightly packed axons with myelin sheathes

6. Parts of the Brain Cerebellum Located at the back of the skull
Coordinates and balances muscle movement

7. Parts of the Brain Brain Stem Connects the spinal cord and the brain
Controls most important involuntary actions like blood pressure, heart rate, breathing and swallowing.

8. Parts of the Brain Thalamus Hypothalamus
Receives information from the body and relays the information to the correct section of the brain.
Hypothalamus
Control center for hunger, thirst, fatigue etc.

9. Spinal Cord
A thick bundle of nerve axons that connect the brain to the rest of the body
Reflexes – a quick, automatic response – is controlled by the spinal cord

10. Peripheral Nervous System
All nerves and cells located outside of the spinal cord
Somatic Nervous system
Controls skeletal muscles
Autonomic Nervous System
Controls involuntary responses.

11. Reflex Arcs Five parts: Sensory Receptor – takes in stimulus
Sensory Neuron- relays impulse to spinal cord
Interneuron-relays impulse to motor neuron
Motor neuron- carries impulse to muscle
Effector – the muscle that moves.