Ch. 11 pt2 - Electricity

Question 1

voltage

Answer 1

a measure of potential energy generated by separated charge

Question 2

higher voltage =

Answer 2

greater charge difference between points

Question 3

insulator

Answer 3

substance with high electrical resistance

Question 4

conductor

Answer 4

substance with low electrical resistance

Question 5

Ohm’s Law

Answer 5

more voltage=greater current; more resistance=smaller current

Question 6

chemically gated channels

Answer 6

open only with binding of a specific chemical (neurotransmitter)

Question 7

voltage gated channels

Answer 7

open and close in response to changes in membrane potential

Question 8

mechanically gated channels

Answer 8

open and close in response to physical deformation of receptors (sensory receptors)

Question 9

graded potentials

Answer 9

incoming signals operating over short distances

Question 10

action potentials

Answer 10

long distance signals of axons

Question 11

depolarization

Answer 11

decrease in membrane potential (towards zero); inside of membrane becomes less negative than resting membrane potential

Question 12

hyperpolarization

Answer 12

increase in membrane potential (away from zero); inside of membrane becomes more negative than resting membrane potential

Question 13

receptor potential

Answer 13

graded potentials in receptors of sensory neurons

Question 14

postsynaptic potential

Answer 14

neuron graded potential

Question 15

Action Potentials are used in..

Answer 15

muscle cells and axons of neurons

Question 16

Generating an Action Potential

Answer 16

(1) resting stage; (2) depolarization; (3) repolarization; (4) hyperpolarization

Question 17

generating AP - resting state

Answer 17

all gated Na+ and K+ channels are closed

Question 18

generating AP - depolarization

Answer 18

Na+ channels open

Question 19

generating AP - repolarization

Answer 19

Na+ channels are inactivating, K+ channels open

Question 20

generating AP - hyperpolarization

Answer 20

some K+ channels stay open, and Na+ channels reset

Question 21

refractory period

Answer 21

neuron can’t trigger another AP (Na+ channels are open, so neuron can’t respond to another stimulus)

Question 22

absolute refractory period

Answer 22

AP is all-or-none event; enforces one-way transmission of nerve impulses

Question 23

relative refractory period

Answer 23

only strong stimulus could stimulate an AP

Question 24

continuous conduction

Answer 24

slow; in nonmyelinated axons

Question 25

saltatory conduction

Answer 25

fast; in myelinated axons

Question 26

synapse

Answer 26

connect neurons

Question 27

presynaptic neuron

Answer 27

conducts impulses towards synapse (sends info)

Question 28

postsynaptic neuron

Answer 28

transmits electrical signal away from synapse (receives info)

Question 29

synaptic cleft

Answer 29

separate chemical synapses

Question 30

excitatory postsynaptic potentials

Answer 30

depolarization

Question 31

inhibitory postsynaptic potentials

Answer 31

hyperpolarization

Question 32

Acetylcholine (ACh)

Answer 32

released at neurotransmitter junctions

Question 33

serial processing

Answer 33

input travels along one pathway

Question 34

reflex arcs

Answer 34

receptor, sensory neuron, CNS integration center, motor neuron, effector

Question 35

diverging circuit

Answer 35

one input, many outputs (amplifying circuit)

Question 36

converging circuit

Answer 36

many outputs, one input (concentrating circuit)

Question 37

reverberating circuit

Answer 37

signal travels through a chain of neurons, each feeding back to previous neurons (oscillating circuit); breathing, walking sleep-wake cycle

Question 38

parallel after-discharge circuit

Answer 38

signal stimulates neurons arranged in parallel arrays that eventually converge on a single output cell; impulses reach output cell at different times, causing a burst of impulses (after-discharge)