Chapter 8

Question 1

What does electrical signals in neuron entail?

Answer 1

Nerves and muscles are excitable, they can propagate signals into action potential to respond to stimuli, and this is all due to RMP and selective permeability of ion channels

Question 2

What charge does the inside of a neuron have at rest?

Answer 2

Negative

Question 3

What does RMP provide?

Answer 3

Chemical and electrical potential energy

Question 4

What is another word for membrane potential?

Answer 4

Equilibrium potential

Question 5

What is membrane potential influenced by?

Answer 5

Uneven distribution of charged ions across a cell
and
Differing membrane permeability to those ions

Question 6

What is hyperpolarization or repolarization?

Question 7

What is depolarization?

Question 8

Where is sodium, chloride, and calcium are more concentrated?

Answer 8

Extracellular fluid

Question 8

Where is potassium more concentrated?

Answer 8

Cytosol

Question 9

What is RMP primarily determined by?

Answer 9

Potassium

Question 10

Goldman-Hodgkin-Katz equation means what?

Answer 10

It predicts the membrane potential due to effects of all ions across the membrane

Question 11

Depolarization

Answer 11

An increase in Na+ permeability will drive Na+ into the cell, down concentration gradient, making the inside more positive

Question 12

Hyperpolarization

Answer 12

An increase in K+ permeability will drive K+ out of the cell, down concentration gradient, making the inside more negative

Question 13

When do gated channels open and close?

Answer 13

As response to stimuli

Question 14

What makes mechanically gated channels open?

Answer 14

In response to physical forces, such as pressure and stretch

Question 15

What makes chemically gated channels respond?

Answer 15

To a variety of neurotransmitters, neuromodulators, or intracellular signals

Question 16

What are the two main cells of the nervous system?

Answer 16

Neurons - the basic signalling unit
Glial cells - support cells

Question 17

What part of the neuron receives signals?

Answer 17

Dendrites

Question 18

What part of the neuron carries outgoing signals?

Answer 18

Axons

Question 19

What is the site of communication in the neuron?

Answer 19

Synapse

Question 20

Do neurons make up majority of the nervous system?

Answer 20

No

Question 21

What is the cell body the site for?

Answer 21

Integration of electrical signals and protein synthesis

Question 22

What happens at the axon hillock?

Answer 22

Where axon begins and where action potential is produced

Question 23

What are the two basic electrical signals?

Answer 23

Graded potentials and action potentials

Question 24

Graded potentials

Answer 24

waves of depolarization that travel over short distances in the dendrites and cell body and lose strength; always the first signal

Question 25

Action Potential

Answer 25

Brief, large depolarizations that travel for long distances along an axon without losing strength

Question 26

Do graded potentials lose strength as they move through the cell?

Answer 26

Yes

Question 27

What does EPSP and IPSP

Answer 27

Excitatory post-synaptic potential Inhibitory post-synaptic potential

Question 28

Does stronger stimuli produce larger graded potential?

Answer 28

Yes

Question 29

If stimulus is large enough at axon hillock, it will hit the threshold to open what?

Answer 29

Na+ channels, meaning graded potential will produce action potentials

Question 30

How far do action potentials travel?

Answer 30

The length of an axon

Question 31

What are the steps of K+ and Na+ moving across membrane in action potential?

Answer 31

1. RMP 2. Depolarizing stimulis 3. Mem dep to threshold and gates open 4. Rapid Na+ dep the cell 5. Na+ chan close and slow and K+ open 6. K+ moves cell to ECF 7. K+ chan remain and open and additional K+ leaves hyperpolarizing the cell 8. K+ chan close 9. Cell returns to normal

Question 32

Axonial Na+ channels have how many gates?

Answer 32

2 Activation gates - open quick Inactivation gates - close slow

Question 33

What do action potentials conduct away from?

Answer 33

The soma

Question 34

What influences conduction of velocity?

Answer 34

Axon diameter and the resistance of the membrane ion leakage (larger diameter of axon, more leakage resistant)

Question 35

Is conduction water in myelinated neutrons or non myelinated axons?

Answer 35

Myelinated, increases resistance

Question 36

Saltatory Conduction

Answer 36

The rapid method by which nerve impulses move down a myelinated axon with excitation occurring only at nodes

Question 37

Are most synapses chemical?

Answer 37

Yes

Question 38

What are the two types of neurocrine receptors?

Answer 38

inotropic and Metabotropic

Question 39

Ionotropic receptors

Answer 39

Open when ligand binds, is fast movement and changes movement of ions

Question 40

Metabotropic receptors

Answer 40

Secondary, with amplification and cascades, transducer through g-coupled proteins

Question 41

What is Acetylcholine?

Answer 41

A chemical that carries messages from your brain to your body through nerve cells

Question 42

What does it mean to be Cholinergic?

Answer 42

Neurons that secrete ACh and receptors that bind ACh

Question 43

What type of action does Ach have?

Answer 43

Excitatory reaction on nicotinic receptors on skeletal muscles

Question 44

What is the main excitatory neurotransmitter of CNS?

Answer 44

Glutamate

Question 45

What is the main inhibitory neurotransmitter in the brain?

Answer 45

Gamma-aminobutyric acid

Question 46

Is the first part of graded potential nicotinic?

Answer 46

Yes

Question 47

Where are neurotransmitters stored?

Answer 47

Axon terminal in synaptic vessels

Question 48

What is the purpose of a synapse?

Answer 48

To send a message

Question 49

How do you recycle ACh

Answer 49

Broken down in synaptic cleft by acetylcholinesterase, choline then moved to axon terminal with Na+ to make more ACh

Question 50

What does the frequency of action potential firing indicate?

Answer 50

The more stimuli the more neurotransmitters released

Question 51

Convergence (integration of neural info)

Answer 51

Many presynaptic neurons provide input to influence a smaller number of postsynaptic neurons (peripheral)

Question 52

Divergence (integration of neural info)

Answer 52

one presynaptic neuron branches to effect a large number of post synaptic neurons

Question 53

Apparent vs Epparent

Question 54

Fast Synaptic Potentials

Answer 54

Involve opening of ion channels

Question 55

Slow synaptic potentials

Answer 55

Involve G-protein coupled receptors and secondary messengers

Question 56

What is Temporal Summation?

Answer 56

Between excitatory and inhibitory GP when multiple impulses arise at a single synapse

Question 57

What is Spatial Summation

Answer 57

When multiple impulses arrive at more than one site

Question 58

What does integration mean?

Answer 58

When excitatory and inhibitory GP determine if a cell fires action potential based on threshold

Question 59

What is the difference between global and selective presynaptic inhibition?

Answer 59

Global targets everything, where inhibitory only targets one thing

Question 60

What are the sensory afferent types

Answer 60

Bipolar nuerons, and pseudounipolar

Question 61

What is an efferent effector?

Answer 61

A multipolar neuron, has many dendrites, and a single long axon

Question 62

What is anterograde transport?

Answer 62

From the cell body to axon terminal

Question 63

What is retrograde transport?

Answer 63

from axon terminal to cell body

Question 64

What are the three main glial cells?

Answer 64

Oligodendrocytes (CNS) and Schwann (PNS) cells which have myelin sheaths and satellite cells (PNS)