Chap 11

Question 1

CNS

Answer 1

brain and spinal cord

Question 2

PNS

Answer 2

nerves outside CNS

Question 3

Sensory (Afferent)

Answer 3

convey impulses to CNS

Question 4

Motor (Efferent)

Answer 4

-convey impulses from the CNS

Question 5

Motor nerves can either be…

Answer 5

voluntary or involuntary

Question 6

Neurons

Answer 6

excitable cells

Question 7

Neuroglia = glial cells

Answer 7

supporting cells

Question 8

Sensory neurons carries signal to

Answer 8

CNS

Question 9

Motor neurons carries signals from the

Answer 9

CNS to muscles

Question 10

Astrocyte

Answer 10

• supporting neurons by anchoring

- maintain blood-brain barrier

Question 11

Microglia

Answer 11

Phagocytes that consume debris, bacteria and dead cells

Question 12

Ependymal cells

Answer 12

epithelial cells that line brain and spine

Question 13

Oligodendrocytes

Answer 13

myelinate CNS axon

Question 14

Satellite cell

Answer 14

• surround neuron cell bodies in ganglia
• regulate O2 and CO2
• protect and cushion PNS

Question 15

Schwann Cells

Answer 15

• surround all axons in PNS

- myelination

Question 16

Function of Myelin

Answer 16

increases impulse propagation rate

Question 17

Satellite Cells and Schwann cells are part of what NS

Answer 17

Peripheral

Question 18

Oligodendrocytes, Astrocytes and Microglia are part of what NS

Answer 18

Central

Question 19

Ganglion

Answer 19

a collection of neural cell bodies inside PNS

Question 20

Nuclei

Answer 20

a collection of neural cell bodies inside CNS

Question 21

What cells can direct the regrowth of severed axons?

Schwann or Oligodendrocytes

Answer 21

Schwann

Question 22

Potential difference or electrochemical gradient is a

Answer 22

cell at rest

Question 23

If a cell is left undisturbed it will maintain a ____ indefinitely.

Answer 23

resting membrane potential

Question 24

How do ions cross cell membrane without ATP

Answer 24

1. Leakage Channels
   - leak either Na or K
2. Gated Channels
   - voltage gated
   - chemical gated
   - mechanically gated
3. Na/ K pump
   - pump 3 Na ions out, 2 K ions in for every ATP used

Question 25

Electrochemical gradient

Answer 25

ions move both ways

Question 26

At rest most channels are closed except

Answer 26

Leakage channels

Question 27

If cell is left undisturbed, it will maintain resting membrane potential indefinitely, the cell would be said to be

Answer 27

polarized

Question 28

Factors that change the membrane potential from resting

Answer 28

change in permeability and ion concentrations

Question 29

Resting potential is

Answer 29

- 70mV | - polarized

Question 30

Cell becomes more POSITIVE than resting potential (above -70mV)

Answer 30

Depolarized

Question 31

Cell becomes more NEGATIVE than resting potential (below -70mV)

Answer 31

hyperpolarized

Question 32

Depolarization can led to

Answer 32

graded potential and action potential

Question 33

Depolarization steps

Answer 33

1. Membrane exposed to chemical that opens the Na ion channels - Na moves into cell 2. Na ions spread creating a small depolarized area

Question 34

Graded Potential

Answer 34

- used for short distance communication | - may cause depolarization or hyperpolarization

Question 35

Action Potential steps

Answer 35

resting state -70mV 1. depolarization of threshold 2. Na channels open and rapid depolarization 3. Na channels close and K channels open 4. return to normal permeability -70mV

Question 36

Action Potential =

Answer 36

all or none response

Question 37

What starts at the Initial Segment

Answer 37

Action potential

Question 38

What starts at the axon hillock

Answer 38

graded potential

Question 39

How is the action potential conducted without fading out like gradient potential?

Answer 39

AP is an all or none event

Question 40

Why does the conduction of AP along the axon only move in one direction?

Answer 40

the axon hillock does not have any voltage-gated Na channels

Question 41

In cells that are myelinated, the AP skips the internodes, and so travels rapidly from ...

Answer 41

node to node

Question 42

Conduction in a myelinated neuron steps

Answer 42

1. AP at initial segment 2. Depolarization to threshold at node 1 3. AP at node 1 4. Depolarization to threshold at node 2

Question 43

Conduction Velocity depends on

Answer 43

-presence of myelin sheath -axon diameter (large diameter conducts faster)

Question 44

Types of Nerve fibers

Answer 44

Type A, B, C

Question 45

Type A

Answer 45

- largest axons | - conduct sensory info from skin and instructions to skeletal muscle

Question 46

Type B

Answer 46

small, myelinated axons

Question 47

Type C

Answer 47

small, unmyelinated axons

Question 48

Function of B and C

Answer 48

transmit sensory info

Question 49

Electrical synapse

Answer 49

- direct ion flow | - very fast

Question 50

Chemical Synapse

Answer 50

-synthetic transmission

Question 51

Postsynaptic Potentials spread toward the

Answer 51

initial segment

Question 52

Temporal Summation

Answer 52

second depolarization occurs before recovery from first

Question 53

Spatial Summation

Answer 53

2 postsynaptic potentials occur at same time in diff places, effect increased

Question 54

Complex responses are built on synaptic interactions (steps) stimulation response

Answer 54

1. Arrival of stimulus and activation of receptor 2. Activation of sensory neuron 3. Info processing in CNS 4. Activation of motor neuron 5. Response by effector