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29.1-2 Nervous System and Neurons. 2.1 Atoms, Ions, and Molecules. Set up Cornell Notes on pg. 31 Topic: 29.2 Nervous System and Neurons Essential Question(s) : Draw and label a neuron on pg. 46 in picture bubble map format. KEY CONCEPT
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29.1-2 Nervous System and Neurons 2.1 Atoms, Ions, and Molecules Set up Cornell Notes on pg. 31 • Topic: 29.2 Nervous System and Neurons • Essential Question(s): • Draw and label a neuron on pg. 46 in picture bubble map format. KEY CONCEPT The nervous system provides the means by which organ systems communicate and is composed of highly specialized cells.
KEY CONCEPT The nervous system provides one of the means by which organ systems communicate.
The nervous system controls thoughts, movement, and emotion as well as simpler life processes such as swallowing
spinal chord nerves • The nervous system works quickly, using chemical and electrical signals. • interconnected network of cells (hardwired) • signals move through cells (neurons) • divided into central nervous system (CNS) and peripheral nervous system (PNS) • CNS- brain and spinal cord • PNS-network of nerves that transmit messages to and from the PNS to the CNS
KEY CONCEPT The nervous system is composed of highly specialized cells.
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 axon neurotransmitter Dendrites
1 Cell body Neurons are highly specialized cells. • A neuron has three parts. 1. cell body has nucleus and organelles
2 dendrites 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 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 Specialized support cells- such as the myelin sheath- insulate neurons’ axons and helps them send messages
Directions: Please make a picture bubble map of this neuron. Use p. 876-879 in your book to help you. Label all major parts of a neuron (cell body, dendrites, axon, myelin sheath, axon terminals, action potential, synapse, neurotransmitters). Once all parts are labeled, you need to describe the function of each.
Synapse: Gaps between neurons Synapse
Neurotransmitters: Chemical signals released by neurons. Carry information from neuron to neuron. Neurotransmitters
Action Potential: Electrical impulse that carries messages Dendrites receive action potential
NEURON Dendrites of next neuron
Axon terminal: releases neurotransmitters (chemical signals) Synapse (gap) Axon terminal Dendrites of next neuron
Check your labels: Neurotransmitters NEURON Synapse Cell body axon Myelin sheath Axon terminal Dendrites Action potential
Neurons transmit information in the form of electrical and chemical impulses • When a neuron is stimulated, it produces an electrical signal (action potential) within that neuron • Electrical Impulse reaches axon terminal
synapse 2. Before it can move to the next cell it changes into a chemical signal (neurotransmitter) 3. Neurotransmitters (chemicals) release into synapse. 4. Neurotransmitters stimulate next cell. neurotransmitter vesicles receptor
How does the structure of a neuron make it effective in carrying out the functions of the nervous system?
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 Types of Neurons 2.1 Atoms, Ions, and Molecules Set up Cornell Notes on pg. 33 • Topic: 29.2 Types of Neurons • Essential Question(s): • None.
There are 3 types of neurons: • Sensory neurons • Interneurons • Motor neurons
1. Sensory Neurons: (Think Senses) • Function: Sensory receptors gather information from external/ internal environment and carry impulses along sensory neurons to the CNS • NO INTERPRETATION • Located in PNS Outside: Light & Sound Intensities Inside: Temperature Oxygen Levels pH Levels
2)Interneurons: • Function: Receives signals from sensory neurons and processes and interprets these messages withinthe CNS • Makes decisions on what needs to be done • Sends messages/instructions to motor neurons • Located in CNS
3)Motor neurons: • Function: Carry nerve impulses out of the brain or spinal cord to effectors • Effectors: muscles and glands will execute a specific task • Located in the PNS.
Key: Motor Neurons Effectors Receptors Sensory Neurons Interneurons Draw/label on p. 33 1._______________ 2. ________________ 3. ______________ 4. _____________ 5._____________
Key: Motor Neurons Effectors Receptors Sensory Neurons Interneurons 1. Receptors 2. Sensory Neurons 3. Interneurons 4. Motor Neurons 5. Effectors
Key: Motor Neurons Effectors Receptors Sensory Neurons Interneurons 1. 2. 3. 5. 4.
In a nutshell…. • The nervous system can: • Detect changes in the body • Make decisions based on the info received • Stimulate muscles and/or glands to respond • Counteract changes to maintain homeostasis
Types of Neurons “Story” Tree Map (P. 32) Sensory NeuronsInterneuronsMotor Neurons • Function • Location • Function • Location • Function • Location • Give a real life example (Tell a story) • Draw a picture for each 1. The phone rings. The sensory neurons in your ear gather the sound information and send it to the CNS 2. Your brain interprets this information and identifies the sound as the phone ringing. This info is sent to the motor neurons 3. The motor neurons send nerve impulses to your muscles which allow you to answer the phone