Chapter 11 Highlights Flashcards

1
Q

Anatomical divisions of the nervous system

A
  • Central nervous system

- Peripheral nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Central nervous system

A

Brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Brain

A
  • Billions of nerve cells

- Protected by bones of skull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Spinal cord

A
  • Begins at foramen magnum
  • Continues through vertebral foramina of cervical to first or second lumbar vertebra
  • Millions of neurons, fewer than brain
  • Enables brain to communicate with most of body below head and neck
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Peripheral nervous system

A

All nerves in the body outside the protection of the skull and vertebral column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Nerves

A
  • Axons of neurons bundled together with blood vessels and connective tissue
  • Carry signals to and from CNS
  • Classified by origin or destination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cranial nerves

A

12 pairs of nerves traveling to or from brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Spinal nerves

A

1 pair of nerves traveling to or from the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Functional divisions of the nervous system

A
  • Sensory

- Motor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Sensory (afferent) nervous system

A
  • Gathers info about internal and external environments

- Carries signals from receptors to the spinal cord and the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Divisions of afferent division

A
  • Somatic sensory division

- Visceral sensory division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Somatic sensory division

A
  • Special sensory division

- Carries signals from skeletal muscles, bones, joints, and skin, organs of vision, hearing, taste, smell, and balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Visceral sensory division

A

Transmits signals from heart, lungs, stomach, kidneys, and urinary bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Divisions of efferent division

A
  • Somatic motor division

- Autonomic nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Somatic motor division

A
  • Neurons transmit signals to skeletal muscle

- Voluntary control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Autonomic nervous system

A
  • Neurons carry signals to thoracic and abdominal viscera
  • Critical for maintaining homeostasis
  • Regulates secretion of certain glands, contraction of smooth muscle and cardiac muscle
  • Involuntary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Neurons

A

Excitable cells responsible for sending and receiving signals as action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Parts of a neuron

A
  • Cell body (soma)
  • Dendrites
  • Axon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Soma

A
  • Most metabolically active region

- Manufactures proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Dendrites

A
  • Short, branched processes

- Receive input from other neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Axon

A

Generate and conducts action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Axon hillock

A

Where axon originates from cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Axon terminals

A
  • Synaptic bulbs

- Components that communicate with target cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Interneurons

A

Relay info within CNS b/t sensory and motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Neuroglial cells

A
  • Astrocyte
  • Oligodendrocyte
  • Microglial cell
  • Ependymal cell
  • Schwann cells
  • Satellite cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Function of Astrocyte

A
  • Anchor neurons and blood vessels
  • Regulate the extracellular environment
  • Facilitates the formation of the blood brain barrier
  • Repair damaged tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Function of Oligodendrocyte

A

Myelinate certain axons in the CNS

28
Q

Function of Microglial cell

A

Act as phagocytes

29
Q

Function of Ependymal cell

A
  • Line cavities
  • Manufacture and circulate cerebrospinal fluid
  • Ciliated cells
30
Q

Function of Schwann cells

A

Myelinate certain axons in the PNS

31
Q

Function of Satellite cells

A

Surround and support cell bodies

32
Q

White matter

A
  • Composed of myelinated axons

- Appear white

33
Q

Gray matter

A
  • Composed of neuron cell bodies and unmyelinated axons

- Appear gray

34
Q

Voltage-gated channels

A

Open in response to changes in voltage across membrane

35
Q

Graded potentials

A
  • Small local changes in potential of neuron’s plasma membrane
  • Triggers for long-distance action potentials
36
Q

Effects of graded potentials

A
  • Depolarization

- Hyperpolarization

37
Q

Depolarization

A
  • Positive charges enter cytosol

- Make membrane potential less negative (change from -70 to -60 mV)

38
Q

Hyperpolarization

A
  • Either positive charges exit or negative charges enteer cytosol
  • Makes membrane potential more negative (change from -70 to -80 mV)
39
Q

Action potential

A

Uniform, rapid depolarization and repolarization of membrane potential

40
Q

States of voltage-gated potassium channels

A
  • Resting

- Activated

41
Q

Resting state

A
  • Channels are closed

- No potassium ions are able to cross plasma membrane

42
Q

Activated state

A
  • Channels are open

- Potassium ions are able to flow down concentration gradients

43
Q

Action potential steps

A

1) Graded potential depolarizes (usually -55 mV)
2) Voltage-gated sodium channels activate and sodium ions flow into axon causing depolarization (positive feedback loop amplified output)
3) Sodium ion channels inactivate and voltage-gated potassium ion channels activate; Na ions stop flowing into axon; K begins exiting axon as repolarization begins
4) Na channels return to resting state and repolarization continues
5) Axolemma may hyperpolarize before K ion channels return to resting state, then return to resting potantial

44
Q

Refractory Period

A
  • Period after neuron has generated action potential

- Neuron cannot be stimulated to generate another action potential

45
Q

Phases of refractory period

A
  • Absolute

- Relative

46
Q

Absolute refractory period

A

No additional stimulus is able to produce additional action potential

47
Q

What channels are open/closed during absolute refractory period?

A
  • Coincides with voltage-gated Na channels being activated and inactivated
  • Na channels may not be activated until they return to resting states
48
Q

Relative refractory period

A
  • Follows immediately after absolute refractory period

- Only strong stimulus can produce action potential

49
Q

What channels are open/closed during relative refractory period?

A
  • Na channels are at resting state, able to open again
  • K channels are activated and membrane is repolarizing or hyperpolarizing
  • Takes MUCH larger stimulus to trigger action potential
50
Q

Conduction speed

A
  • Rate of propagation
  • Influenced by both axon diameter and myelination
  • Determines how rapidly signaling can occur within nervous system
51
Q

What makes conduction speed greater?

A
  • Larger diameter –> faster

- Lower resistance

52
Q

Saltatory conduction

A
  • In myelinated axons

- AP jumps from node to node (nodes of Ranvier)

53
Q

Continuous conduction

A
  • In unmyelinated axons

- Every section of axon has to conduct action potential

54
Q

Axon classification by conduction speed

A
  • Type A
  • Type B
  • Type C
55
Q

Type A

A
  • Fastest conduction speeds
  • Largest diameter
  • Myelinated
  • Sensory and motor axons associated with skeletal muscle and joints
56
Q

Type B

A
  • Slower conduction speeds
  • Mostly myelinated with intermediate diameter axons
  • Efferent fibers of autonomic nervous system and some sensory axons
57
Q

Type C

A
  • Slowest conduction speeds
  • Smallest diameter fibers
  • Unmyelinated axons include efferent fibers of ANS and sensory axons
  • Transmits pain, temperature, and certain pressure sensations
58
Q

What happens at the chemical synapse?

A
  • More complicated than neuromuscular junctions

- Multiple neurons secreting many different types of excitatory or inhibitory neurotransmitters

59
Q

Steps occurring at the chemical synapse

A

1) Action potential in presynaptic neuron triggers opening of voltage-gated Ca ion channels in axon terminal
2) Ca ions cause synaptic vesicles to release neurotransmitter into synaptic cleft
3) Neurotransmitters bind to receptors on postsynaptic neuron
4) Ion channels open, leading to local potential and possibly action potential if threshold is reached

60
Q

Postsynaptic potentials

A

Local potentials in membranes of postsynaptic neuron

61
Q

Excitatory postsynaptic potential (EPSP)

A
  • Membrane potential of postsynaptic neuron moves closer to threshold
  • Caused by small local depolarization
62
Q

Inhibitory postsynaptic potential (IPSP)

A
  • Membrane potential of postsynaptic neuron moves farther away from threshold
  • Caused by small local hyperpolarization
63
Q

Types of summation

A
  • Temporal

- Spatial

64
Q

Temporal summation

A
  • Neurotransmitter released repeatedly from single presynaptic neuron
  • Short-lived, so must be generated quickly to reach threshold
65
Q

Spatial summation

A

Simultaneous release of neurotransmitters from axon terminals of many presynaptic neurons