The Endocrine System

Page
2

Slide 10

The Nervous System

Communication

Electrical

Slide 11

Main Function:

This communication system controls and coordinates functions throughout the body and responds to internal and external stimuli.

The Nervous System

Our nervous system allows us to feel pain.

Slide 12

Consists of: brain, spinal cord, nerves and sense organs

The Nervous System

Sense Organs: Eyes, Skin, Ears, Nose & Tongue

Slide 13

The Nerve

A nerve is an organ containing a bundle of nerve cells called neurons.

Neurons carry electrical messages called impulses throughout the body.

Picture shows hundreds of severed neuron axons

Slide 14

Impulse in a Neuron

cell

body

Slide 15

Because neurons never touch, chemical signalers called neurotransmitters must travel through the space called synapse between two neurons.

Neurotransmitters

Synapse (gap)

The message is transferred when RECEPTORS receive neurotrans-mitters.

(pink

spheres)

Slide 16

Parts of a Neuron

Cell body: contains nucleus & most of the cytoplasm

Dendrites: projections that bring impulses into the neuron to the cell body.

Axon: long projection that carries impulses away from cell body

Slide 17

Sensory Neuron

Interneuron

Motor Neuron

Types of Neurons

Sensory Neuron

Interneuron

Motor Neuron

Muscle Contracts

Synapse

Synapse

Synapse

Slide 18

Sensory Neuron

carry impulses from sense organs to spinal cord & brain

Fun Fact:

Where can the largest cells in the world be found?

The giraffe’s sensory and motor neurons! Some must bring impulses from the bottom of their legs to their spinal cord several meters away!!

Slide 19

Interneuron

processes impulses in brain and spinal cord

- connect sensory and motor neurons

Slide 20

Motor Neurons

carry impulses from the brain & spinal cord to muscles & glands