Lecture 6 part one (SECOND MIDTERM) Flashcards Preview

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Flashcards in Lecture 6 part one (SECOND MIDTERM) Deck (70):
1

How is the nervous system fast acting?

It uses electrical impulses

2

The nervous system is derived from what germ layer?

Ectoderm

3

The CNS is derived from...
The PNS is derived from...

CNS = neural ectoderm
PNS = neural crest

4

Unlike the CNS, the PNS is always...

paired; spinal nerves and cranial nerves come out from the left and from the right

5

Somatic refers to the things you do _________ and visceral refers to the things you do __________.

consciously, unconsciously

6

Somatic sensory name:
Visceral sensory name:

Somatic afferent: skeletal muscle, joints, skin sensations
Visceral afferent: internal organ sensations

7

Somatic motor name:
Visceral motor name:

Somatic efferent: voluntary contractions
Autonomic Nervous System (ANS): controls itself

8

Somatic motor nerves send messages where?

Musculature of body wall (somatopleure)

9

Visceral sensory nerves receive signals from where?

Organs of splanchnopleure
(examples: hunger, discomfort, full bladder, etc.)

10

afferent:
efferent:

afferent: toward
efferent: away

11

4 divisions of the nervous system:

Somatic sensory
Somatic motor
Visceral sensory
Visceral motor

12

The way we refer to the visceral efferent division:

Autonomic Nervous System

13

2 divisions of the Autonomic Nervous system,:

Parasympathetic
Sympathetic

14

Basic component of the nervous system:

Neurons

15

Other cells that serve as supporting cells:

Glial cells

16

Neurons abilities:

-Can respond to stimuli
-Can conduct an electrical signal

17

Anatomy of a motor neuron
Cell body:
Dendrites:
Axon:
Telodendria:
Synaptic terminals:

Cell body: expanded portion
Dendrites: processes that come off the cell body
Axon: longer process
Telodendria: axon divides into these
Synaptic terminals: at the end of telodendria

18

Where is the nucleus located?

The cell body

19

Where is the stimulus received?

Either by the dendrites or on the cell body itself; "On or near the cell body"

20

The axon is covered by a cell membrane. What is it called?

Axolemma

21

Direction of impulse:

Cell body > Axon > Telodendria > Synaptic terminals > next cell

22

What is used to communicate with the next cell?

Synaptic terminals

23

4 different types of neurons:

Anaxonic: no axon (in brain)
Bipolar: 2 axons (special senses, like in nose)
Unipolar: cell body, but just one axon in which the cell body is offset (looks like 2)
Multipolar: one cell body but many dendrites; one axon

24

What kind of neuron is typical for a motor neuron?

Multipolar neuron

25

What kind of neuron is typical for a sensory neuron?

Unipolar neuron

26

Proper name for unipolar neurons:

pseudounipolar neurons

27

IMPORTANT CONCEPT (in Noriega's words)
Communication happens.....

ON OR NEAR CELL BODY

28

Stimulus:

Change in property of neuron cell membrane

29

What is myelin? What is it used for?

it is a fat that insulates & causes repression of signal degradation

30

How does the electrical signal usually enter?

via dendrites

31

How does the electrical signal usually leave?

via axon

32

What does myelin prevent?

-prevents the electrical charge from leaking out; "short circuit" (electrical barrier)
-it is a PHYSICAL barrier

33

In the PNS, myelin is produced by ________ cells called ___________.

neuroglial, Schwann

34

In the CNS, myelin is produced by _________ cells called ______________.

neuroglial, Oligodendrocytes

35

Where there is no myelin and the axolemma is exposed, there is a:

Node (of Ranvier) or Neuralfibro nodes

36

Another difference between Schwann cells in the PNS and Oligodendrocytes in the CNS is...

One single Schwann cell will only cover one portion of a single axon
Several processes coming off an Oligodendrocyte will cover multiple segments of multiple axons
*Both have insulating function!

37

A bundle of axons (neurons) in the PNS? In the CNS?

PNS: nerve
CNS: tract

38

What is a ganglion? Where is it?

A collection of cell bodies
PNS

39

What is a collection of cell bodies in the CNS?

Nucleus

40

Define a resting membrane potential.

Electrical charge across a cell membrane when the cell is at rest

41

If one side has a different charge than the other, it is said to be...

polarized

42

What is the electrical charge at rest?

-70mV

43

What does it mean to have an electrical charge of -70mV?

It is the different between the inside of the membrane and the outside of the membrane
(The inside is 70mV more negative than the outside)

44

What is the charge difference due to?

The differential distribution of charged ions on either side of the membrane

45

Sodium is actively pumped out of the cell, leaving more sodiums on the outside than on the inside. The pump that does this is:

the sodium potassium-exchange pump

46

What is the sodium-potassium exchange pump powered by? When doesn't it work?

ATP
It's always working (unless you're dead)

47

Ratio of potassium that go in and sodium that goes out:

2 potassium in, 3 sodium out

48

What is the net movement?

1 positive charge gets pumped out; this is how you build a positive charge on the outside of the cell

49

The inside of the cell is ________ more negative than the _________.

-70mV, outside

50

Leak channels work to do what?

they establish a normal resting membrane potential; sodium is able to "leak" back into the cell or the potassium is able to "leak" back out of the cell

51

If the pump is always working, what will happen to the charge difference?

It will get bigger and bigger; -70 to -80 to -90 and so on

52

The sodium-potassium pump and leak channels work to reach...

equilibrium

53

The chemical gradient is what?

the concentration gradient

54

Despite its desire to go back out of the cell, potassium will want to stay in the cell because of:

the electrical gradient

55

What is stronger, chemical gradient or electrical gradient? What does this mean?

Chemical gradient
This means if you let potassium do what it naturally wants to do, it will leave the cell

56

If you combine the two gradients, you will get...

the electrochemical gradient

57

If the membrane were freely permeable to potassium ions, the outflow of potassium would continue until what was reached? What's the value?

equilibrium potential; -90mV

58

If the membrane were freely permeable to sodium ions, the influx of sodium would continue until what was reached? What's the value?

equilibrium potential; +66mV
Will become more positive on the inside

59

Learning catalytics:
Where is the sodium concentration higher?
If it's just concentration gradient, which way will sodium want to go?
Based on electrical gradient, where will sodium want to go?

-Outside the cell
-Inside of the cell
-Inside the cell

60

What usually triggers an impulse?

A change in the electrical potential (the -70mV charge)

61

The change in the electrical potential is usually caused by...

A change in the cell membrane permeability

62

What factors can cause the permeability change of the plasma membrane?

-Can be cause by a stimulus
-Signal from neighboring cell
-Deformation of receptor cell of a special sense

63

Different gated-channels:

-Chemically gated (ligand-gated) channels
-Voltage gated channels
-Mechanically gated channels

64

Chemically gated...

open or close when they bind specific chemicals
(example: the receptors that bind acetylcholine at the neuromuscular junction)

65

Voltage gated...

open or close in response to changes in the membrane potential

66

If a stimulus is strong enough to trigger an impulse, it is called a:

threshold stimulus

67

A threshold stimulus is for what kind of channel?

Voltage gated channel
(it is an electrical value)

68

A graded potential just means...

as you move away from the center (the strongest change), the difference gets "smaller and smaller"

69

For voltage-gated channels at what mV do these events occur?
Opening of inactivation gate:
Opening of activation and inactivation gate:
Close of inactivation gate:

Opening of inactivation gate: -70mV
Opening of activation and inactivation gate: -60mV
Close of inactivation gate: +30mV

70

Spread of sodium ions inside plasma membrane produces a local current that does what?

depolarizes adjacent portions of the plasma membrane