Physiological Basis of Regional

Question 1

Myelination of axon in the PNS is by

Answer 1

Schwann Cells

Question 2

Wrapping concentric rings of its plasma membrane Called _____Around the axon

Answer 2

Myelin Sheath

Question 3

Cytoplasm and the nucleus squeezed outside of the myeline sheath is called

Answer 3

Neurilemma

Question 4

What is the space between adjacent myelin sheath called?

Answer 4

Node of Ranvier

Question 5

Myelination of axon in the CNS is by

Answer 5

Oligodendrocytes

Question 6

Axons in the CNS are myelinated by extension from the oligodendrocytes therefore

Answer 6

Neurelimma is absent

Question 7

How does myelination help impulse

Answer 7

Impulse move faster by jumping from node to node

Question 8

Interruptions in the axon are called

Answer 8

Nodes of Ranvier

Question 9

Allows axolemma to be exposed to the extracellular matrix

Answer 9

Nodes of Ranvier

Question 10

How does the nerve impulse travel along unmyelinated axons

Answer 10

As a uniform wave of depolarization due to conformational changes in ion channels

Question 11

In myelinated axons, these ion channels like booster stations for

Answer 11

Propagation of passively conducted electrical current

Question 12

Describe peripheral nerve

Answer 12

mixed nerve type with both efferent and afferent , myelinated and unmyelinated fibers.

Question 13

Which layer surrounds each individual axon

Answer 13

Endoneurium

Question 14

Contain the nerve fibers in fascicle

Answer 14

Perineum

Question 15

Which membrane is the semipermeable membrane that acts as a major barrier to diffusion of local anesthetics

Answer 15

Perineum

Question 16

The sheath covering the entire nerve that contains nutrient blood vessels

Answer 16

Epineurium

Question 17

Classification of A fibers (DGBA)

Answer 17

Delta
Gamma
Beta
Alpha

Question 18

What are the A fibers responsible for

Answer 18

Motor, tactile, proprioception , muscle tone touch

Question 19

Responsible for pain and temperature

Answer 19

Small A Delta fibers

Question 20

Which fibers are the autonomic preganglionic fibers

Answer 20

B fibers

Question 21

Which fibers are the post ganglionic autonomic pain and temp

Answer 21

C fibers

Question 22

The only unmyelinated fibers

Answer 22

C fibers

Question 23

A fibers Alpha and Beta responsible for

Answer 23

Motor and proprioception

Question 24

Describe the cell membrane

Answer 24

Phospholipid bilayer
Semipermeable
Integral proteins and transmembrane
Electrical capacitance

Question 25

Sodium Channels

Answer 25

Protein channel

Change configuration in response to membrane potenitial

Question 26

Sodium channels potential

Answer 26

Depolarizing potential-> decrease electrical tension OPEN

Hyperpolarizing potentials –> Increase tension and CLOSE THE CHANNEL, Rapid activation

Question 27

Potassium channels

Answer 27

slowly activate when membrane depolarizes

RELAEASE K out of the cell

Question 28

Accounts for the resting membrane potential

Answer 28

Potassium channels

Question 29

K passively exits the cell and set the potential

Answer 29

NERST potential

Question 30

What changes the EP across the cell membrane

Answer 30

Depolarization which inducing conformational changes in adjacent ion channels opening voltage gated channels

Question 31

What allow the establishment of the RMP

Answer 31

Leaking K channels.

Question 32

Phases of the AP

Answer 32

Resting
Depolarization
Repolarization
Hyperpolarization
Refractory interval

Question 33

Resting phase

Answer 33

Subthreshold depolarization

Only few Na open

Question 34

Hyperpolarization

Answer 34

K channels are wide open

Question 35

Action Potential propagation

Answer 35

Passive spread
Active spread-in axon
Myelinated : node to node
Non-myelinated: continuous wave

Question 36

Once an action potential is initiated in one region

Answer 36

the depolarization wave will spread out sequentially to the rest of the neuron