Nervous System

Front 1

The nervous system is divided into which to parts?

Back 1

Central & Peripheral

Front 2

The CNS consists of which 2 parts?

Back 2

Brain and spinal nerves

Front 3

The PNS consists which kind of nerves?

Back 3

Afferent and Efferent nerves

Front 4

What are 2 types of cells in the nervous system?

Back 4

Neurons and Neuroglia

Front 5

What are the functional units of the NS?

Back 5

Neurons

Front 6

What are 5 x more common than neurons?

Back 6

glial

Front 7

What are the 3 parts of the neuron?

Back 7

cell body, dendrites, and axon

Front 8

What receives information and conveys it to the cell body?

Back 8

Dendrites

Front 9

What conducts nerve impulses toward the CNS?

Back 9

Sensory

Front 10

What conducts nerve impulses toward the CNS?

Back 10

Sensory Neurons

Front 11

What carries impulses out of the CNS?

Back 11

Motor Neurons

Front 12

What is a Nerve?

Back 12

A bundle of axons in the PNS

Front 13

What are groups of cell bodies outside the CNS?

Back 13

ganglion

Front 14

What myelinates several CNS Axons?

Back 14

Oligodendrocytes

Front 15

What are groups of cell bodies outside the CNS?

Back 15

ganglion

Front 16

Which cells myelinate PNS axon

Back 16

Schwann Cells

Front 17

What kind of charge do Cations have?

Back 17

positive (K+ or Na+)

Front 18

Waht kind of charge do Anions have?

Back 18

negative charge (Cl- or proteins)

Front 19

What is membreane potential

Back 19

separation of opposite charges across plasma membrane

Front 20

What is membrane potential?

Back 20

separation of opposite charges across plasma membrane

Front 21

RMP of most cells is?

Back 21

-65 to -85 mV

Front 22

At rest most cells have a negative internal charge and ...

Back 22

unequal distribution of ions

Front 23

At rest most cells have a negative internal charge and unequal distribution of ions.
Results from...

Back 23

-large ions being trapped inside cell
-Na+/K+ pump
-limited permeability keep Na+ high outside cell
-K+ is very permeable and nigh inside cell

Front 24

What is Electrogenic

Back 24

3 Na+ pumped for every 2 K+ taken in

Front 25

Depolarize

Back 25

membrane potential above resting

Front 26

Repolarize

Back 26

return to normal

Front 27

Repolarize

Back 27

return to normal

Front 28

Repolarize

Back 28

return to normal

Front 29

Hyperpolarization

Back 29

membrane potiental below resting (becomes more negative)

Front 30

What does abnormal increase of K+ in blood plasma do?

Back 30

-reduces membrane potential
-interferes with electrical activity of heart

Front 31

Voltage gated (VG) Channels

Back 31

-opened by depolarization
-closed in resting cells
-VG Na+ & K+ channels

Front 32

What is AP/Nerve impulse?

Back 32

A wave of change in the membrane potiental due to movement of ions in axon membrane

Front 33

Depolarization and Repolarization occur via?

Back 33

diffusion and do not require active transport

Front 34

Steps in Action Potential

Back 34

1. Stimulus opens Na+ channels
2. Voltage sensitive Na+ channels open
3. Na+ channels close

Front 35

Steps in Action Potential

Back 35

1. Stimulus opens Na+ channels
2. Voltage sensitive Na+ channels open
3. Na+ channels close
4. Voltage sensitive K+ channels open
5. Na+/K+ pump restores concentration

Front 36

In AP if a single shock is given to a neuron it will either

Back 36

"fire" if threshold is reached or
"not fire" if threshold is not reached

greater stimulus does not increase size of action potiental

Front 37

What are local anesthetics?

Back 37

-block conduction of AP/nerve impulses in sensory axons
-bind to VG Na+ channels
-Prevents depolarization and AP

Front 38

Depolarization of axons produced by...

Back 38

Inward diffusion of Na+ repolarization is outward diffusion of Ka+

Front 39

Coding for stimulus intensity

In a neuron

Back 39

-Increased stimulus intensity causes more APs to be produced per second (frequency increased)
-Size of AP's remain constant

Front 40

Coding for Stimulus Intensity

In a Nerve, electrical activity of a nerve can be intensified by

Back 40

increasing either frequency or strength

Front 41

Coding for Stimulus intensity in a nerve

As the strength (voltage)is increased

Back 41

-the # of depolarized axons increases
-increasing the amplitude (size of AP)
-AP are graded ( varied)

Front 42

Coding for stimulus intensity in a nerve

As the frequency is increased

Back 42

number of impulses conducted increases

Front 43

Absolute refractory period

Back 43

membrane cannot produce another AP because Na+ channels are inactivated

Front 44

relative refractory period

Back 44

occurs when VG K+ channels are opened & Na+ channels are recovering from inactivated state

Front 45

During Refractory Period, AP can only go away from

Back 45

cell body

Front 46

During 1st part of repolarization a region of the axon

Back 46

can not be stimulated

Front 47

During refractory period, can a region of the axon be stimulated?

Back 47

during the later part of repolarization, a region of the axon can be stimulated, but it must be a large stimulus to reach threshold

Front 48

What does myelination do to nerve impulses?

Back 48

Makes conduction of nerve impulses faster

Front 49

In The PNS each Schwann cell...

Back 49

mylinates axon by wrapping around it

electrically insulates axon

Front 50

Saltatory conduction is

Back 50

the rapid passage of action potentials from one node of Ranvier to another in myelinated axons

Front 51

The absolute refractory period of a neuron occurs during...

Back 51

depolarization and 1st part of repolarization phase

Front 52

The conduction of AP's ion myelinated nerve fiber is...

Back 52

-saltatory
-without decrement (doesn't decrease)
-faster than unmyelinated fibers