29.2 Neurons SPONGE 3

1. Why does your body need a communication system?

2. Which system, the endocrine or the nervous, controls the rate at which you blink?

3. How might a clogged blood vessel affect the endocrine system’s ability to deliver signals?

29.2 Neurons

1. Why does your body need a communication system?

• A communication system allows the body to respond to its environment and maintain homeostasis 2. Which system, the endocrine or the nervous, controls the rate at which you blink?

• The nervous system controls the rate of blinking because it controls fast processes.

3. How might a clogged blood vessel affect the endocrine system’s ability to deliver signals?

• A clogged blood vessel might slow down the delivery of signals by the endocrine system, but not the nervous system

29.2 Neurons

Quick Send Includes Slower CNS and PNS Connected network Controls thoughts and movement signals disconnected

Nervous system

Respond to stimuli

Endocrine system

Chemical Maintain homeostasis Signals Controls Electrical Signals growth and development

29.2 Neurons Standard 9.d

Students know the functions of the nervous system and the role of neurons in transmitting electrochemical impulses.

Standard 9.e

Students know the roles of sensory neurons, interneurons, and motor neurons in sensation, thought, and response.

29.2 Neurons KEY CONCEPT The nervous system is composed of highly specialized cells.

29.2 Neurons

Neurons (aka nerve cells)are cells that can store information and send and receive messages within the nervous system. • Make up an information network (Like the internet)

Cell body Dendrites axon neurotransmitter

29.2 Neurons Neurons are highly specialized cells.

• A neuron has three parts.

1. cell body has nucleus and organelles

1 Cell body

29.2 Neurons Neurons are highly specialized cells.

• A neuron has three parts.

1. cell body has nucleus and organelles 2. dendrites receive messages from neighboring cells

2 dendrites

29.2 Neurons Neurons are highly specialized cells.

• A neuron has three parts.

1. cell body has nucleus and organelles 2. dendrites receive messages from neighboring cells 3. axon carries messages to other cells

3 axon

29.2 Neurons Draw and label this neuron: Cell body axon Dendrites Myelin sheath neurotransmitter

29.2 Neurons Sponge 4

Neurons (nerve cells) are cells that can store information and send and receive messages.

In a paragraph, hypothesize how drug or alcohol use might affect neurons?

29.2 Neurons How does the structure of a neuron make it effective in carrying out the functions of the nervous system?

29.2 Neurons

How does the structure of a neuron make it effective in carrying out the functions of the nervous system?

Neurons have long extensions called axons, which allow messages to be carried long distances without having to pass the signal to another cell.

29.2 Neurons

There are 3 types of neurons: 1)Sensory neurons : detect stimuli and transmit signals to the brain and the spinal cord 2)Interneurons : receive signals from sensory neurons and relay them within the brain and spinal cord 3)Motor neurons : pass messages from the nervous system to the other tissues in the body, such as muscles * Specialized support cells- such as the myelin sheath insulate neurons’ axons and helps them send messages

29.2 Neurons

• Neurons transmit information in the form of electrical and chemical impulses – When a neuron is stimulated, it produces an electrical signal within that neuron – Before it can move to the next cell it changes into a chemical signal – You react

29.2 Neurons

– Electrical Impulse reaches terminal.

terminal impulse

29.2 Neurons

– Electrical Impulse reaches terminal.

impulse

29.2 Neurons

– Electrical Impulse reaches terminal.

– Neurotransmitters (chemicals) release into synapse.

impulse vesicles synapse neurotransmitter receptor

29.2 Neurons

– Electrical Impulse reaches terminal.

– Neurotransmitters (chemicals) release into synapse. – Neurotransmitters stimulate next cell.

synapse impulse receptor neurotransmitter vesicles