Chap 3 Neurophysiology

Question 1

Electrostatic Pressure

Answer 1

A passive physical force that causes ions to flow towards oppositely charged areas

Question 2

Sodium-Potassium Pump

Answer 2

a protein embedded in the cell membrane that actively uses energy to pump out three sodium (Na+) ions for every two potassium (K+) ions pumped in the cell

Question 3

postsynaptic potentials

Answer 3

brief changes in the membrane potential of the postsynaptic cell in response to neurotransmitter

Question 4

selective permeability

Answer 4

some substances can pass through the cell membrane (K+) while others cannot

Question 5

Exogenous Ligand

Answer 5

chemical molecules introduced from outside the body (poisons, drugs, or toxins)

Question 6

voltage-gated

Answer 6

an ion channel that only opens when the cell membrane reaches a particular electrical charge

Question 7

ions

Answer 7

electrically charge molecules

Question 8

hyperpolarization

Answer 8

an increase in membrane potential; the inside of the cell becomes even more negative

Question 9

Threshold

Answer 9

the stimulus intensity needed to trigger an action potential (-40mV)

Question 10

depolarization

Answer 10

a decrease in membrane potential; the inside of the cell becomes less negative

Question 11

Cell Membrane

Answer 11

lipid bilayer that creates the outer boundary of the cell; a semipermeable membrane

Question 12

diffusion

Answer 12

a passive physical force that causes ions to spread towards a uniform concentration

Question 13

resting potential

Answer 13

the stable, negative charge of an active neuron (-50 to -80 mV)

Question 14

Graded Potential

Answer 14

local changes in membrane potential that fade over time, come in varying strengths and spread passively

Question 15

neurotransmitter

Answer 15

chemical messengers that transmit information between neurons

Question 16

continuous condution

Answer 16

each adjacent section of the axon is depolarized and a new action potential is created at each point alont the axon; slower conduction (10m per second)

Question 17

IPSP

Answer 17

produces a small hyperpolarization of the postsynaptic cell when chloride (CI-) ions enter, making it less likely that the neuron will fire

Question 18

complex partial seizure

Answer 18

a seizure that doesn’t involve the entire brain; can lead to a wide variety of symptoms depending on which part of the brain is impacted

Question 19

ligand-gated

Answer 19

an ion channel that only opens when a particular chemical molecule is bound

Question 20

Electroencephalogram (EEG)

Answer 20

a recording of spontaneous brain potentials, or brain waves, taken through large electrodes placed on the scalp

Question 21

EPSP

Answer 21

produces a small depolarization when Na+ ions enter the postsynaptic cell; increase the likelihood that that neuron will fire

Question 22

Complex Partial Seizure

Answer 22

local changes in membrane potential that fade over time, come in varying strengths, and spread passively

Question 23

Petit Mal Seizure

Answer 23

a synchronization of brain waves for a short period of time, during which a person stops and stares but does not have convulsions

Question 24

Enogenous Ligand

Answer 24

chemical molecules created inside the body (neurotransmitters or hormones)

Question 25

Spatial Summation

Answer 25

Inputs that arrive at different point on the dendrite or cell body are integrated together

Question 26

Gran Mal Seizure

Answer 26

a synchronization of electrical activity throughout the entire brain; loss of consciousness followed by muscle convulsions

Question 27

All-or-nothing property

Answer 27

the neuron fires at full amplitude or not at all; action potentials only come in one strength

Question 28

Relative Refractory Phase

Answer 28

a period when only strong stimulation can produce an action potential

Question 29

Event-Related Potentials (ERPs)

Answer 29

a recording of brain potentials, or brain waves, in response to a single stimulus (such as flash of light or a loud sound)

Question 30

saltatory conduction

Answer 30

the action potential jumps from one node of Ranvier to the next in a myelinated axon; fast transmission (150 meters per second)

Question 31

Agonist

Answer 31

an exogenous ligand that increased the effectiveness of a neurotransmitter

Question 32

Antagonist

Answer 32

an exogenous ligand that interferes with the effectiveness of a neurotransmitter

Question 33

cation

Answer 33

positively charge molecule (ex:Na+, K+)

Question 34

postsynaptic potential

Answer 34

brief changes in the membrane potential of the postsynaptic cell in response to neurotransmitter

Question 35

ligand

Answer 35

a molecule that fits a receptor binding site exactly and can either activate or block the receptor

Question 36

Absolute Refractory Phase

Answer 36

regardless of the amount of stimulation receive the neuron cannot fire another action potential

Question 37

equilibrium potential

Answer 37

the electrical charge that perfectly balances the forces of diffusion and electrostatic pressure for a certain ion

Question 38

diffusion

Answer 38

a passive physical force that causes ions to spread towards a uniform concentration

Question 39

temporal summation

Answer 39

input that arrive at different points in time are integrated together

Question 40

Action Potential

Answer 40

a brief electrical shift that travels the length of the axon

Question 41

epilepsy

Answer 41

a seizure disorder

Question 42

anion

Answer 42

negatively charged molecules (ex:CI-)

Question 43

mechanically-gated

Answer 43

an ion channel that only opens in response to mechanical pressure or stretch