1. Movie: Nervous System (27:00min)
The Nervous System
Movie: Nervous System
(27:00min)

2. The Nervous System The body’s command system. Functions:
Communicates information throughout the body and controls the body’s response to stimuli.
Stimuli – any change that happens inside the body or in the surrounding environment.
Functions:
Takes in and processes information about the environment.
Coordinates the actions of the body’s skeletal muscles.
Allows communication
Regulates all activities the body can perform.

3. Organization of the Nervous System
Made up of nervous tissue
Main organs:
Brain
Spinal cord
Sensory organs; eyes, ears, nose, tongue, and skin
Has two divisions:
Central nervous system (CNS)
Peripheral nervous system (PNS)

4. Nervous Tissue Made up of cells called Neurons Message carrying cells
Dendrites
Cell Body
Nucleus
Axon
Axon
Terminals
Synapse

5. Characteristics of a Neuron
Neurons can NEVER be replaced!
Parts of the Neuron:
Dendrites
Carry impulses toward the cell body
Cell body
Contains the nucleus
Controls all the activities of the cell
Axon
Carry impulses away from the cell body
Axon Terminal
Ends of an axon
Pass a message on to the neighboring neuron’s dendrites
Synapse
Space separating the axon terminal of one neuron and the dendrites of the neighboring neurons.

6. Nerve Impulse
The message being carried throughout the body by nerves - Nerve Impulse.
ONLY travesl in one direction
Travels as fast as 120 m/sec
Carried as both electrical and chemical messages
Messages come in from different stimuli and trigger electrical impulses
At the end of the axon it is changed into a chemical message so it can cross over the synapse – neurotransmitters.

7. Nerve Impulse Synapse Dendrites Cell Body Nucleus Axon Axon Terminals
Come in as
electrical signals
Changed to
Chemical Signals
Dendrites
Cell Body
Nucleus
Axon
Axon
Terminals
Synapse

8. Types of Neurons 3 Types of Neurons:
Sensory Neuron – picks up stimuli from the internal and external environments.
Location where the stimuli is received - Receptor.
Interneurons – carry nerve impulses from one neuron to another.
Brain interprets the message and determines appropriate reaction.
Motor Neuron – Send an impulse to the muscle resulting in a response to the stimuli.
Muscle tissue responds to the impulse - Effector

9. 1
____ Receptors in your ear hear the phone. ____ Receptors trigger nerve impulses in sensory neurons. ____ Nerve impulses pass to interneurons in the brain. ____ Your brain interprets the impulses from many interneurons and you realize the phone is ringing. Your brain also decides that you should answer the phone. ____ Impulses travel along motor neurons to the muscles. ____ Muscles in the arm carry out the response and you reach to pick up the phone - effector. 2 3 4 5 6

10. Central Nervous System (CNS)
Brain
Made up of the brain and spinal cord.
Forms the largest part of the nervous system.
Responsible for communication, memory and thought.
Spinal
Cord

11. Peripheral Nervous System (PNS)
Connects the brain and spinal cord to the rest of the body.
Made up of:
12 pairs of cranial nerves
31 pairs of spinal nerves
2 divisions:
Somatic
Controls voluntary actions
jogging
Autonomic
Controls involuntary actions
Breathing & digestion
Spinal
Nerves