1. Write everything that is BLACK
Section 29-2 “Neurons”
Write everything that is BLACK

2. State Standards
As a result of the coordinated structures and functions of organ systems, the internal environment of the human body remains relatively stable (homeostatic) despite changes in the outside environment. As a basis for understanding this concept:
D. Students know the functions of the nervous system and the role of neurons in transmitting electrochemical impulses.
E. Students know the roles of sensory neurons, interneurons, and motor neurons in sensation, thought, and response.

3. KEY CONCEPT The nervous system is made up of highly specialized cells.

4. Neurons are highly specialized cells.
A neuron (nerve cell) has three parts:
the cell body has nucleus and organelles
Draw & Label Picture below 1
Cell body

5. Neurons are highly specialized cells
A neuron (nerve cell) has three parts:
the cell body has nucleus and organelles
the dendrites receive (get) impulses 2
dendrites

6. Neurons are highly specialized cells
A neuron (nerve cell) has three parts:
the cell body has nucleus and organelles
the dendrites receive (get) impulses
the axon carries impulses 3
axon

7. Neurons have other structures to transmit signals:
Schwann cell (shwän-\)
these insulate the neuron (like the plastic coating around electrical cords)

8. Neurons have other structures to transmit signals:
Schwann cell
Synapse (si-naps)
This is where the 2 neurons join together

9. Neurons have other structures to transmit signals
Schwann cell
synapse
axon terminal (end of the axon)

10. Neurons receive and transmit signals
Resting potential means no signal is being transmitted
more Na+ outside of cell
(Na + is sodium ion)
more K+ inside of cell
(K + is potassium ion)

11. An action potential is a moving electrical impulse
It is generated by a stimulus.
Na+ enters, and cell becomes positively charged.
K+ leaves, and area of positive charge moves
area of detail

12. There’s a little space where the synapse is so the neurons don’t actually touch ….
they need a chemical messenger to get across the gap
Neurotransmitter: chemical message that stimulates the next neuron in the chain
You have lots of these in your brain and around your body: seritonin, adrenaline, dopamine
They make you feel happy, sad, excited
Depression can be caused by an imbalance of these neurotransmitters
Drug use (heroin, cocaine) will also cause these to become imbalanced

13. A chemical signal passes between neurons Impulse reaches terminal
These are 2 different neurons (axon to dendrite)

14. A chemical signal passes between neurons Impulse reaches terminal

15. A chemical signal passes between neurons Impulse reaches terminal
Neurotransmitters released into synapse
synapse
impulse
neurotransmitter
vesicles
receptor

16. A chemical signal passes between neurons Impulse reaches terminal
Neurotransmitters released into synapse
Neurotransmitters stimulate next cell
synapse
impulse
neurotransmitter
vesicles
receptor
Watch Neurons BrainPOP w/ Activity HO