Unit 2: Part 1A: Neurons

Question 1

Dendrite

Answer 1

receptors; receives information; where the neurotransmitters or chemicals land

Question 2

Soma Cell Body

Answer 2

where the nucleus is located; sums up information to see if neuron is at rest or threshold

Question 3

Axon Hillock

Answer 3

beginning of axon; if threshold is reached it initiates an electric signal impulse (one way)

Question 4

Axon

Answer 4

where the electrical signal or action potential occurs; sends the message

Question 5

Myelin Sheath

Answer 5

coating of fat; protects axon and contains the electrical signal; helps with speed of impulse

Question 6

Nodes of Ranvier

Answer 6

spaces between myelin sheath; amplifies the signal or gives a boost to electrical signal (speed action potential)

Question 7

Terminal

Answer 7

end point; helps the neuron communicate as it sends chemical

Question 8

Neurotransmitters

Answer 8

chemicals sent out from the terminal to communicate with other neurons/dendrites; serotonin, clopamine

Question 9

Reuptake

Answer 9

process where the terminal vacuums or absorbs chemicals after they are released

Question 10

Synapse

Answer 10

the space or area where two neurons meet communication occurs between the presynaptic neuron and postsynaptic neuron

Question 11

Afferent Neurons

Answer 11

sensory receptors to brain; approach the brains

Question 12

Efferent Neurons

Answer 12

motor from brain; exit the brain

Question 13

Interneurons

Answer 13

internal functions; between

Question 14

Excitatory Messages

Answer 14

increase the likelihood of neuron firing

Question 15

Inhibitery Messages

Answer 15

decrease the likelihood of neuron firing

Question 16

All-or-None

Answer 16

neurons fire or they don’t

Question 17

Action potential

Answer 17

once it starts, it cannot stop

Question 18

Resting Potential

Answer 18

ready to fire; in polarized state (mostly negative)

Question 19

Threshold is Reached

Answer 19

level of stimulation required to trigger neural impulse

Question 20

Depolarization (Na+ floods in)

Answer 20

becomes less negative

Question 21

Repolarization (Na+ floods out)

Answer 21

becomes more negative

Question 22

Restractory Period

Answer 22

resting phase

Question 23

Reuptake

Answer 23

excess neurotransmitters are reabsorbed

Question 24

Neurons Rest

Answer 24

-70mV (resting potential)

Question 25

Message Received

Answer 25

Sodium Ion gates open up -55mv (threshold is reached); All-or-None response

Question 26

Potassium and Sodium Meet

Answer 26

creates a charge +30mV; charge bounces down the axon, opening more ion gates

Question 27

Neuron dip

Answer 27

-90mV; enters retractory period