Do now Grade Brainpop 1 What is a

Do now Grade Brainpop! 1. What is a neuron? 2. What is the nervous system? 3. What makes up your nervous system? 4. What does your nervous system control?

Monday/Tuesday, April 8 th, 2013 Your Learning Goal: Students will be able to explain why people become paralyzed when they break their back using the terms motor neuron, axon, dendrite, and neurotransmitter. Standard: 5 a. Levels of organization 5 b. Students know that organ systems function because of the contributions of individual organs, tissues, and cells. The failure of any part can affect the entire system Table of Contents: 7. 3 Nervous System Homework: See next page Agenda: 1. 2. 3. 4. 5. 6. Do-Now: Reading Notes on neurons Wipe board races Notes on neuron communication Reflex Activity if time Start HW if time

• • • Assignments that must be completed when we return from spring break Assigned 4/10 or 4/11 Due 4/21 or 4/22 7. 02 Musculoskeletal Worksheet and Lever Arm 7. 1 Be perfect Reading 7. 1 Be Perfect Webquest 7. 2 Neuron Brainpop 7. 3 Nervous System Worksheet 7. 3 Nervous System Flashcards – 18 Terms • Will Post an extra credit assignment on the website this weekend. Spent all night in the hospital without internet

• • • • • New Vocab Words Nervous System Brain Spinal Chord Nerve Neuron Central Nervous System Peripheral Nervous System Neuron Sensory neurons Motor Neurons Interneurons Dendrite Cell Body Nucleus Axon Terminals Neurotransmitter Synapse

Spinal Cord Injury TPS • When someone breaks their back, why do you think they become paralyzed? Why can’t they move from the waste down (paraplegic) or the neck down (quadriplegic)? I think that people become paralyzed because….

Levels of Organization: The Nervous System • Our bodies are organized into different sized groups: -Cells Tissues Organ Systems Organism (smallest) (largest) -All organisms are made up of cells. -The same cell working together make up tissues. Neurons work together to make nervous tissue! -Groups of tissues make up organs (eye, stomach, brain). Nerves are an organ made up of nervous tissue and other connective tissues. -An organ system is a group of organs that work together (Nervous system is made up of the brain, spinal chord, and nerves).

Brain What is the Nervous System • Nervous system: The organ system responsible for sending and receiving information in the body Spinal cord – Tells muscles to contract and relax – Time to move – Info from the external environment – “IT SMELLS LIKE DINNER IS READY” – Info from inside the body – “I NEED MORE OXYGEN” Nerves

3 Organs OF THE NERVOUS SYSTEM 1. Brain: The ‘control center’ of the body; controls and interprets all information in the body 2. Spinal cord: major network of nerves in the body; connects to the brain to the rest of the body. The spinal chord is responsible for sending information from the brain to the rest of the body (and viceversa) 3. Nerve: A group of neurons (and other cell tissues) that carry information from the spinal chord to the rest of the body (and viceverca) Brain Spinal cord Nerves

The nervous system is split into 2 parts 1. The Central Nervous System (CNS) is made up of the brain and spinal cord and its job is to control the entire body. 2. The peripheral nervous system is made up of all of the nerves that carry messages to and from the central nervous system (all of the neurons outside of the brain and spinal cord). CNS PNS

Check Point: Questions You will see 1. Which organ of the nervous system connects your brain to the rest of your body? 2. Which organ of the nervous systeis the command center of your body? 3. Which organ of the nervous system sends and receives information to your limbs? 4. Which part of the nervous system is your spinal chord in? PNS or CNS? 5. Which part of your nervous system are your nerves in? PNS or CNS? 6. Which part of your nervous system is your Brain in? PNS or CNS?

What is a Neuron l A neuron is a nerve cell. Neurons carry information through the nervous system. Neurons Communicate through electrochemical signals l The neuron basic unit of the nervous system and is the cell we are talking about when we talk about nerves.

What are the 3 types of neurons in 1. Sensory neurons carry messages from your body our bodies: to your brain or spinal cord. (from the spinal Sensory Interneuron cord, the interneurons Spinal cord take the message to the Motor neuron Receptor in skin brain) Direction of impulse Muscle contracts Reflex: Before the brain even gets information from touching the hot bowl, you jerk your hand back. After your reflex, the message makes it to your brain. 2. Motor neurons carry messages from your brain to the muscles in your body telling them to contract and move. 3. Interneurons carry messages inside your brain and spinal cord.

TYPE OF NEURONS CFU • Wipe Board Races!

What kind of neuron is this? Carries messages from the brain to muscles in the face, making the baby smile.

What kind of neuron is this?

What kind of neuron is this? Brain sends message to muscles in the leg so that they kick.

What kind of neuron is this? Finger sends touch message to neuron which takes the message to the brain.

Spinal Cord What kind of neuron is this? A neuron that sends information in the brain and spinal cord.

What kind of neuron is this? Neurons receive a message from Kayne’s brain and take it to the muscles in his face so that he sings.

What kind of neuron is this? -Works inside the spinal cord.

What kind of neuron is this? Neurons in the dog’s ear send pain message to the brain.

What kind of neuron is this? Works inside brain and spinal cord.

What kind of neuron is this? Neurons in a man’s hand sends the heat message to the brain.

What kind of neuron is this?

What Happens in a relay • How do you think neurons relate to a relay race?

Relaying an impulse 1. Receptors in the neuron sense a touch. 2. Sensory neurons carry the touch message to the brain. 3. The brain interprets the message from the sensory neurons. A response is sent to the motor neurons. 4. Motor neurons carry a message back to the muscles in your neck. 5. The neck muscles are activated and the neck turns. l The nervous system sorts and interprets incoming information before directing a response.

What are the parts of a Neuron (Nerve Cell)? • Dendrites- receives chemical messages called • • neurotransmitters from other neurons. This starts the electrical impulse in the neuron! Cell Body: Holds the Nucleus and other organelles Nucleus: Holds the DNA Axon- sends electrical impulses through the neuron (signals) Axon Terminals- : Sends message to another neuron releases neurotransmitters to the dendrites of other neuron (or muscle)

CFU Neuron (Nerve Cell)

Connections between neurons Dendrite -Although neurons lie end to end, they do not touch!!! Axon Impulse - Synapse: That gape between neurons! -The axon of the presynaptic neuron (the neuron in front of the synapse) sends a neurotransmitter across the synapse to the dendrite of the post synaptic neuron (the neuron after the synapse) Synapse Dendrite Impulse Axon

Neurotransmitter: The baton messenger • A neurotransmitter is a chemical that activates (starts) an electrical impulse (wave) in a neuron (or makes a muscle contract for motor neurons). • Electrochemical Signal: . Electrical Impulse goes down the axon and gets to the end and releases a chemical signal (the neurotransmitter)

How do impulses get across the synapse? Dendrite Impulse Axon Synapse Dendrite Axon Impulse Axon Synaptic space Dendrite When an impulse reaches the end of a neuron, the neuron releases neurotransmitters which diffuse, or move, across the gap between the neurons. These neurotransmitters then activate the next neuron.

How does it all get started? • If neurotransmitters relay the message from neuron to neuron and to the neurons in the brain or cells in the muscle, How do these messages start? • I think the messages start when…

Cutaneous Receptors • Sensory information is received on the skin by special receptors that start signals in sensory neurons. These receptors send neurotransmitters to the first dendrite of the sensory neuron! – Mechanoreceptor: Feels pressure – Thermoreceptor: Feels temperature – Nociceptor: feels pain

So why can’t someone move their legs when they break their back?

Exit Slip 2. What type of neuron sends a message to your muscles telling it to contract? 3. What type of neuron send messages other neurons in your body? 4. What’s the difference between a dendrite and an axon? a. The dendrite releases neurotransmitters and the axon receives neurotransmitters? b. The axon releases the neurotransmitter and the dendrite receives the neurotransmitter c. The dendrite is an electrical signal d. The axon is a chemical signal.

How does this work?

Reflexes -Sometimes a stimulus results in an automatic response that you can’t control. This is called a reflex. The sensory neuron sends a neurotransmitter to a motor neuron in the spinal cord. The motor neuron sends a message to make the muscle contract Sensory neuron Direction of impulse Motor neuron Flexor muscle contracts and withdraws part being stimulated Pain receptors in skin

Reflexes in the Somatic Nervous System -Sometimes a stimulus results in an automatic response that you can’t control. This is called a reflex. The sensory neuron sends a neurotransmitter to a motor neuron in the spinal cord. Sensory neuron Direction of impulse Motor neuron Flexor muscle contracts and withdraws part being stimulated Pain receptors in skin

Neuron Relay Team