1. Nervous System

2. The Nervous System 1. Role of the Nervous system:
Receives, processes and transmits information that comes from the various parts of the body and the external world

3. 2. Neurons The nervous system functions with the help of neurons.
Neurons are specialized cells that receives and transmits messages
Parts of a neuron:
Dendrites
Cell Body
Axon
Axon terminals

4. 2. Neurons A) Role of neurons:
picks up stimuli, transforms them into nerve impulses and transmits these impulses

5. ***A stimulus is anything that can be perceived by a living organism and that can trigger a reaction.
Sound, light, heat, electrical shocks, odors and hormones are examples of stimuli.
***A nerve impulse:
Electrical signal transmitted by a neuron Transmission of nerve impulses

6. 2. Neurons B) Characteristics of neurons Neurons can be stimulated
They are conductive
Consumes a great deal of oxygen and glucose
Can live more than 100 years
Cannot reproduce itself

7. C) Parts of the Neuron

8. Nerve Impulses How it works?
The dendrites receives the message or stimuli and transforms it into a nerve impulse
The nerve impulse is transmitted along the axon
Nerve impulses travel from one neuron to another via neurotransmitters (chemical substance) secreted by axon terminals
A synapse is the transition zone between 2 neurons that allows a nerve impulse to be transmitted

10. D) How it works?
Dendrites: receive and transform information into a nerve impulse
Axon: Carries impulse to axon terminal
Axon Terminal: Via neurotransmitters, passes on the impulse to another neuron or nerve
A synapse is the transition zone between 2 neurons that allows a nerve impulse to be transmitted

11. 3. Central and Peripheral Nervous system

12. A) Central Nervous System
Made of the brain and the spinal cord
The brain:
Cerebrum: command central for voluntary motion, interpretation of sense and of intelligence
Cerebellum: center of balance and movement coordination
Brain stem: control center of internal stimuli and of involuntary movement
Spinal cord:
carries information from the various parts of the body to the brain. It is also the reflex center.
A reflex is a rapid and involuntary reaction to a stimulus
A reflex arc is the path taken by a nerve impulse during a reflex

13. A) Central Nervous system
Parts
Function
Cerebrum
Voluntary motion
Thought
Interpretation
Cerebellum
Movement coordination
Center of balance
Brain Stem
Involuntary movement
Control of internal stimuli
Spinal Cord
Reflexes

14. B) Peripheral Nervous system
Connects different parts of the body to the central nervous system
Nerves are structures that help transmit information between the central nervous system and various regions of the body
There are two main types of nerves:
Sensory
Motor

15. 4. Passing on a message Sensory receptors Sensory Nerves
Picks up stimuli and transforms the stimuli into a nerve impulse
Sensory Nerves
Transmit information, in the form of a nerve impulse from sensory receptors to the central nervous system
Also pick up information from vital organs
Analysis from the Central Nervous system
Motor Nerves
Transmit impulses from the central nervous system to the muscles in order to produce voluntary and involuntary motion

16. For Example Kicking a soccer ball
You see the ball (sight – sensory receptor)
The eye transforms the information into a nervous impulse
The sensory nerves transmit the impulse to the central nervous system
The brain analyses the information
The motor nerves send the “kick” impulse from the brain to the leg muscles