Chapter 6: Neuronal Signaling And Structure Of The Nervous System

Front 1

Neurons travel through

Back 1

membrane potentials

Front 2

Membrane potential changes through

Back 2

graded potentials and action potentials

Front 3

graded potentials

Back 3

relatively small changes, variable in size, degrade with time and distance

Front 4

action potentials

Back 4

large changes, always the same size, do not degrade with time and distance

Front 5

Peripheral nervous system

Back 5

afferent (sensory) input to CNS
efferent (motor) output to muscles/glands

Front 6

Efferent

Back 6

Autonomic system to smooth and cardiac muscle
parasympathetic (rest and digest)
sympathetic (flight or fight)

Front 7

Resting membrane potential

Back 7

Function of ion (K+ and Na+) concentration gradients
Function of leak channels always open
Function of the relative numbers of channels (K+ more than Na+)

Front 8

Dendrites

Back 8

receive info, typically neurotransmitters, then undergo graded potentials

Front 9

Axons

Back 9

use action potentials to deliver information via neurotransmitters from the axon terminals

Front 10

Negative charge inside cell and positive charge

Back 10

outside cell

Front 11

Depolarization occurs when

Back 11

ion movement reduces the charge imbalance = dynamic

Front 12

A cell is polarized because

Back 12

its interior is more negative than its exterior = static

Front 13

Overshoot refers to the

Back 13

development of a charge reversal = dynamic

Front 14

Repolarization is movement

Back 14

back toward the resting potential = dynamic

Front 15

Hyperpolarization is the

Back 15

development of even more negative charge inside the cell = dynamic

Front 16

Graded potentials

Back 16

can be excitatory or inhibitory
are proportional to the size of the stimulus
decay as they move over distance

Front 17

Action potentials

Back 17

all or none

Front 18

Absolute refractory period

Back 18

the time during which another action potential is impossible

Front 19

Relative refractory period

Back 19

the time during which another action potential is possible, but the threshold is higher than normal

Front 20

Action potentials are one way and do not

Back 20

go back and forth

Front 21

Convergence

Back 21

four primary neurons communicate to one secondary neuron

Front 22

Divergence

Back 22

one primary neuron communicate to four secondary neurons

Front 23

The synapse is the

Back 23

point of communication between two neurons that operate sequentially

Front 24

What is the second thing that happens after the action potential reaches the terminal?

Back 24

the voltage-gated Ca2- channels open and calcium enters the axon terminal

Front 25

After the calcium enters

Back 25

neurotransmitter is released and diffuses into the cleft

Front 26

After the neurotransmitter is released and diffuses into the cleft

Back 26

neurotransmitter binds to postsynaptic receptors

Front 27

After the neurotransmitter binds

Back 27

neurotransmitter is removed from the synaptic cleft

Front 28

Excitatory postsynaptic potential (EPSP)

Back 28

graded depolarization that moves the membrane potential closer to the threshold for firing an action potential (excitement)

Front 29

Inhibitory postsynaptic potential (IPSP)

Back 29

graded hyperpolarization that moves the membrane potential further from the threshold for firing an action potential (inhibition)

Front 30

Somatic nervous system

Back 30

Consists of a single neuron between CNS and skeletal muscles
Can only lead to muscle excitation

Front 31

Autonomic nervous system

Back 31

Smooth or cardiac muscles, glands, or GI neurons
Can be either excitatory or inhibitory