Nervous System

Question 1

colloid

Answer 1

trapped charged particle within a membrane

Question 2

nongated ion channels

Answer 2

always open; responsible for the permeability of the plasma membrane to ions when the plasma membrane is at rest

Question 3

gated ion channels

Answer 3

ion channels that open or close in response to stimuli

Question 4

ligand-gated ion channel

Answer 4

(molecule that binds to a receptor); receptor protein or glycoprotein to which a ligand can bind

Question 5

voltage-gated ion channels

Answer 5

open and close in response to small voltage changes across the cell membrane. At rest, membrane is negative on the inside relative to the outside. When cell is stimulated, the relative charge changes and voltage-gated ion channels either open or close.

Question 6

Other gated ion channels

Answer 6

-Touch receptors: respond to mechanical stimulation of the skin
-Temperature receptors: respond to temperature changes in the skin

Question 7

resting membrane potential

Answer 7

the electrical charge of a neuron when it is not active; -70 - -90 mV

Question 8

Hyperpolarization

Answer 8

an increase in the membrane potential of a cell, relative to the normal resting potential

Question 9

graded potentials

Answer 9

can go from weak to strong; strength and frequency of an action potential

Question 10

local potential

Answer 10

an electrical potential that is initiated by stimulation at a specific site, which is a graded response that spreads passively across the cell membrane, decreasing in strength with time and distance

Question 11

depolarization

Answer 11

changing polarity from negative to positive; creating positive electrical charge from a negative

Initiated by opening of sodium activation gates

Question 12

repolarization

Answer 12

creating a negative charge from a positive

initiated by closing sodium inactivation gates and opening potassium activation gates

Question 13

absolute refractory period

Answer 13

amount of time that there is no level of stimulus that can cause the nerve to fire again

Question 14

relative refractory period

Answer 14

a stronger-than-threshold stimulus that can initiate another action potential; time you can have an action potential if the stimulus is strong enough

Question 15

subthreshold stimulus

Answer 15

a stimulus too small to create an action potential in a neuron

Question 16

maximal stimulus

Answer 16

just strong enough to produce a maximum frequency of action potentials

Question 17

submaximal stimulus

Answer 17

all stimuli between threshold and the maximal stimulus strength

Question 18

supramaximal stimulus

Answer 18

any stimulus stronger than a maximal stimulus. These stimuli cannot produce a greater frequency of action potentials than a maximal stimulus.

Question 19

action potential propagation

Answer 19

one way electrical flow of an action potential due to the absolute refractory period

Question 20

saltatory conduction

Answer 20

the jumping of action potentials from node to node due to myelination and cannot move backwards due to repolarization

Question 21

pigmented retina

Answer 21

• outer layer
• keeps light from reflecting back in eye

Question 22

sensory retina

Answer 22

inner layer of rod and cone cells sensitive to light

Question 23

outer plexiform layer

Answer 23

the retinal layer containing axons and dendrites forming connections between bipolar cells, horizontal cells, and the photoreceptors

Question 24

inner plexiform layer

Answer 24

where action potential is between bipolar cells and ganglion and then to optic nerve

Question 25

rhodopsin

Answer 25

protein that changes shape when struck by light and separates to opsin (protein) and retinal (vitamin A)

Question 26

Anaerobic respiration

Answer 26

breakdown of glucose to make ATP and lactic acid

Question 27

aerobic respiration

Answer 27

oxygen breakdown of glucose to produce ATP, carbon dioxide, and water