Ch.3 Study Guide

Question 1

Resting Potential of a neuron is -50 to -80 mV- the negative sign indicated that the cell’s interior is more _________ than the outside.

Answer 1

negative

Question 2

Cell membrane has 2 layers of fatty ____________

Answer 2

molecules

Question 3

Ion Channels are protein that span the membrane and allow ion to ________ through

Answer 3

pass

Question 4

Some ion channels are gated, opening and closing in response to __________

Answer 4

signals

Question 5

Some ions stay open all the time, e.g., the ones that allow potassium (K+) to cross the _____________

Answer 5

membrane

Question 6

The phospho-lipid bilayer is the cell membrane 2 ________ of fatty molecules

Answer 6

layers

Question 7

Na+ is _______________

Answer 7

Sodium

Question 8

K+ is _______________

Answer 8

Potassium

Question 9

Action Potential are actively propagated (regenerated) along the axon through saltatory ___________________, each adjacent section is depolarized and a new action potential occurs

Answer 9

Conduction

Question 10

Action potential travel in only ____ direction because of the refractory state of the membrane after a depolarization

Answer 10

one

Question 11

Conduction Velocity- the speed of propagation of action potential, varies with axon diameter (bigger = faster). It’s about ___-___ meters/seconds

Answer 11

40-50

Question 12

Vesicle means small ________

Answer 12

vessels

Question 13

Ligands are molecules that fit not receptors and activate or _______ them. Think of a key & lock analogy.

Answer 13

block

Question 14

A synapse that uses acetylcholine (ACh) has ligand-binding sites for ACh on neurotransmitter ____________ molecules in the postsynaptic membrane

Answer 14

receptor

Question 15

Some chemicals can fit on receptors in place of a neurotransmitter: nicotine can mimic ACh on receptors, acting like the transmitter-__________

Answer 15

agonist

Question 16

Any molecule that diminishes or prevents the action of a neurotransmitter is an _______________

Answer 16

antagonist

Question 17

Transmitter action is halted by 2 processes:
- Degradation-the rapid ____________ and inactivation of transmitter by an enzyme, - Reuptake-transmitter is cleared from the synapse by being absorbed back into the presynaptic axon _________

Answer 17

breakdown, terminal

Question 18

_____________ Permeability- allowing some things to pass through, but not others. The membrane allows K+(Potassium), but not NA+(Sodium), to enter or exit the cell fairly freely

Answer 18

Selective

Question 19

Resting Potential is an electrical difference ___________ the membrane

Answer 19

across

Question 20

Anions are negatively charged ______

Answer 20

ions

Question 21

Cations are positively charged ______

Answer 21

ions

Question 22

Cytoplasm is the fluid-filled space within the cell body that contains organelles & other _____________

Answer 22

structures

Question 23

A threshold amount of depolarization triggers an action _____________

Answer 23

potential

Question 24

Depolarization is a increase in _______________ potential; depolarization of a neuron brings its membrane potential closer to zero

Answer 24

membrane

Question 25

Hyperpolarization is an decrease in membrane ____________; the neuron becomes even more negative on the inside, relative to the outside)

Answer 25

potential

Question 26

Action Potential are very brief but large changes in neuronal polarization that arise in the initial segments of the _______, just after the axon hillock

Answer 26

axon

Question 27

Sodium-Potassium pump- pumps 3 NA+ ions out of the cell for every 2 K+(potassium) ions pumped in. This action results in a building of K+ ions inside the _____ and reduces NA+ Sodium _________ the cell

Answer 27

cell, inside

Question 28

Myelin channels the depolarization down the ______ interior

Answer 28

axon

Question 29

The resting potential of the neuron reflects a balancing act between 2 opposing processing that drive K+ ions in and out of the _________. The first of these is _____________ which is the tendency for molecules of a substance to spread from regions if high concentration to regions of low concentration

Answer 29

neuron, diffusion

Question 30

The 2nd force at work is electrostatic ___________, which arises from the distribution of electrical charges rather than the distribution of molecules.

Answer 30

pressure

Question 31

Electrostatic pressure: Charged particulars exert electrical force on one another: like charges repel and ___________ charge attract

Answer 31

opposite

Question 32

When neurotransmitter are released into the synapse by the presynaptic membrane they can: __________ away from the synapses, be broken down by enzymes, or be reuptake back into the presynaptic neuron

Answer 32

diffuse

Question 33

An all-or-none property of the action potential: either it ______ at its full amplitude, or it doesn't fire at all

Answer 33

fires

Question 34

Myelin in the CNS is made of lipids, ___________, and water

Answer 34

proteins

Question 35

Myelin in the PNS is made from the plasma ________ of Schwann cells (which wrap around the axon, forming a tightly coiled insulating layer)

Answer 35

membrane

Question 36

Epilepsy- high-frequency in action ______________ and hypersynchorization of a neuron population

Answer 36

potential

Question 37

The different types of synapses are- Axo-dendritic: Axo-somatic: Axo-axonic: ________________

Answer 37

Dendro-dendritic:

Question 38

Axodendritic synapse is a connection between the axon of one neuron & the dendrite of another neuron(most __________)

Answer 38

common

Question 39

Axo-somatic synapse is a connection between a neuron's axon & its cell _______

Answer 39

body

Question 40

Axo-axonic synapse is a connection between the axon of one neuron & the axon of anther __________

Answer 40

neuron

Question 41

Dendro-dendritic synapse is a specialized connection between the dendrites of _______ neurons; (they allow for direct communication between two dendrites)

Answer 41

two

Question 42

Saltatory ______________ a process by which electrical impulses (action potentials) rapidly propagate along myelinated axons, or nerve fibers, in the nervous system

Answer 42

conduction

Question 43

Nodes of Ranvier- small gaps ___________ about every millimeter along the axon; allows for ions to diffuse in and out of the neuron, propagating the electrical signal down the axon

Answer 43

spaced

Question 44

EEG measures the electrical activity of neurons int he brain by recording ______________ potentials on the scalp; measuring the summed activity of millions of neurons, different frequencies of oscillation....

Answer 44

voltage

Question 45

Temporal Summation is accumulation of rapidly occurring stimuli at a __________ synapse that is activated repeatedly, leading to an increased degree of depolarization & bringing the initial segment to threshold

Answer 45

single

Question 46

Spatial summation occurs when stimuli are applied at the same time, but in different __________, with cumulative effect upon membrane potential

Answer 46

areas

Question 47

Inhibitory postsynaptic potential is known as ______

Answer 47

IPSP

Question 48

Excitatory postsynaptic potential is known as ______

Answer 48

EPSP

Question 49

IPSP- a temporary hyperpolarization of a neuron's membrane that makes it less likely to fire an action ___________

Answer 49

potential

Question 50

EPSP- a change it eh voltage of a cell membrane that occurs when neurotransmitter bind to receptors on the cell's surface. this change makes the cell more likely to fire an action __________

Answer 50

potential