Download Biology Notes: The Nervous System and Neurons

Name: _________________________________________________ Date: _______________ Period: ________ Biology Notes: The Nervous System and Neurons Nervous System • ____________________ of connected cells, tissue, and organs • Controls ____________________, ____________________, ____________________ • Quick responses - Ex: ____________________________________________________________ CNS and PNS • Central Nervous System = ____________________ and ____________________ • Peripheral Nervous System = All the ____________________________________ Neurons • AKA: Highly specialized _______________ cells - Transfer electrical impulses _____________________________________________ • 4 Main Parts - Cell body: contains nucleus and _______________ - Dendrites: branches that _______________________________ from neighboring cells - Axon: extension that carries messages _______________ from the cell body - Axon _______________: End of neuron Three Types of Neurons 1. Sensory - Detect _______________ and transmit signals ______________________________________________ - Detect sense: ________________________________________________________________________ 2. Interneuron - Located in the _______________. Receive signals from the _______________ neurons. 3. Motor - Pass messages to ______________________________ - Ex: ___________________________________________. Muscle reacts by contracting and stretching. Resting Potential • Defined: Neuron ___________________________________ • Neuron Exterior: _______________ charge. - Due to an abundance of _______________ outside the cell. Inside the axon • Neuron Interior: _______________ charge •
- ______________________________________________ - ________________________________________ the cell Draw (+) and (–) to show resting potential Action Potential • Defined: The ______________________________ that is triggered & moves quickly down an axon • Generating the Impulse - Na channels in the membrane ___________ & ___________________ ions diffuse _______ the cell - Area becomes ________________ charged (impulse) • After the Impulse - K channels open to allow ___________ ions exit the cell. Area returns to ______________ charge. - Process continues down the axon Cleaning Up the Mess • Who? _____________________________ • What? - __________ is pumped ____________________ of the cell - __________ is pumped ____________________ the cell • When? _____________________________________________________________________________________ • Where? Located in the cell membrane • Why? _______________________________________________________________________________________ • How? ___________________________________ (REQUIRES _______________) Synapse • Defined: _______________ between neurons • Problem: Impulse _________________ cross the gap • Solution: ______________________ proteins are sent from 1 neuron to another • Steps: 1. Impulse reaches ______________________________ 2. Vesicle releases ________________________, which attach to ______________ on neighboring neuron 3. Channels open on ________________ of neighboring cell. - New ______________ created. Putting it ALL Together: Animation with Steps 1. ________________________________________________________________________________________ 2. ________________________________________________________________________________________ 3. ________________________________________________________________________________________ ________________________________________________________________________________________ 4. ________________________________________________________________________________________ Impulses eventually reach the muscles… and causes MOVEMENT! ReView (at the end of the PowerPoint you should be able to answer these questions) 1. What is the function of the nervous system? 2. List the 4 main parts and describe the purpose of the 4 main parts of a neuron. 3. The nervous system is divided into 2 parts. What are they and what do they include? 4. Describe the internal and external environment of a neuron in resting potential (RP). How is RP reached? 5. What is a synapse and why is it a problem for neurons? 6. To what part of the nervous system do motor neurons, interneurons, and sensory neurons belong? 7. When an impulse is within a neuron it is electrical. When the signal moves to the next neuron it is _________________. What is the specific name for this? 8. Describe how an action potential moves down a neuron.