W7 Nervous system Flashcards

1
Q

List three basic functions of the NS

A
  1. Detect changes (stimuli) in the external and internal environment
  2. Evaluates info
  3. Responds by initiating changes in muscles or glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name and define major anatomical subdivisions of the NS

A
  • The central nervous system

* Peripheral nervous system

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

What are the subdivisions of the PNS?

A
  • The somatic NS
  • The autonomic NS
  • The enteric nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define neuron

A

Carry out most of the functions of the NS.
*Sensing changes on the outside and inside of the body
Moving muscles
Forming memories
Regulating behaviour

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

Describe a neurons important structural components

A

Axon terminal , axon , cell body , dendrites

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

Define neurons and relationship to each functional role

A

Dendrites receive infomation
Cell body - performs function of a cell
Axon - transmits messages to terminal
Axonterminal - communication to other cells (neurotransmitters)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name 3 functional classes of neurons

A

Multipolar
Bipolar
Unipolar

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

Describe the function of Sensory neurons

A

Sensory (Afferent( neurons - detect changes in external and internal environment

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

Identify types of neuroglia in CNS

A

Astrocytes
Oligodendrocytes
Microglia
Ependymal cells

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

Explain the importance of the myelin sheath

A

Formed from wrappings of plasma membrane - appear white

The presence of myelin increases the speed of signal conduction

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

Describe how the myelin sheath is formed in the CNS and PNS

A

Produced by two neuroglia:
Obligodendrocytes - produce myelin sheath in the CNS
Schwann cells - produce myelin sheath in the PNS

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

What is SAME?

A

Somatic Afferent

Motor Efferent

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

What are the two main cell types in the NS?

A

Neurons and Neuroglia

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

Name 3 functional classes of neurons

A
  1. Sensory (afferent) neurons
  2. Interneurons
  3. Motor (efferent) neurons)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the function of Interneurons

A

Involved in the processing of infomation coming into the CNS and initiating actions through motor responses ( telephone component)

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

Describe the function of Motor (efferent) neurons

A

Involved in controlling muscles or glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Neuroglia?

A

Provides chemical and structural support for neurons.

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

Define Astrocytes

A

(CNS)Star shaped; largest most numerous type of glia , which transfer nutrients from the blood to neurons. ( neurganglia function)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Define Obligodendrytes

A

(CNS)Produce a myelin sheath that wraps around axons of CNS neurons (insulation)

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

Define Microglia

A

Acts as immune cells in the CNS destroying foreign organisms and damaged nervous tissue

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

Define Ependymal cells

A

(CNS)Responsible for the production of cerebrospinal fluid. They also aid in the movement of this fluid though ventricles

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

Define Obligodendrytes

A

(CNS)Produce a myelin sheath that wraps around axons of CNS neurons (insulation)

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

Describe the function of Satellite cells in the neuroglia PNS

A

Produce structural support and aid in the exchange of nutrient and the surrounding fluids

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

What parts of neurons make up white matter?

A

Consists of primarily myelinated axons

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

What part of neurons make up grey matter?

A

Consists of neuron cell bodies, dendrites, unmyelinated axons and neurolgia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What part of neurons make up grey matter?

A

Consists of neuron cell bodies, dendrites, unmyelinated axons and neurolgia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the electrochemical basis of the resting membrane potential

A

Polar heads prevent movement of charged particle through the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does the term membrane potential refer to?

A

The difference in voltage between the inside and outside of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is membrane potential measured?

A

Recording electrodes is inserted into the cell the voltage different between the two electrodes is about -70mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the resting membrane potential?

A

Resting membrane potential is the membrane potential recorded when a neuron is not receiving any input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the sodium potassium pump function?

A

PUMPS out 3 Na+ (sodium ions) PUMPS IN 2 K+ ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the sodium-potassium pump do?

A

It helps to establish concentration gradients between the inside and the outside of the cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the potassium leak-channel?

A

Allows potassium to move down(leak out) it’s concentration gradient and outside of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How is the resting membrane potential established??

A

K+ (sodium ions) wants to move DOWN the concerntration gradient out of the cell though the K+ (potassium ions) leak channels. As K+ moves out, the cell becomes more negative.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How can the membrane potential change?

A

Graded potentials

Action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is a graded potential?

A

A graded potential is a small deviation from the resting membrane of the neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is summation?

A

Is the process by which graded potentials occurring close enough in time together can produce a bigger change in membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is summation?

A

Is the process by which graded potentials occurring close enough in time together can produce a bigger change in membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How do neurons communicate?

A
  1. The generation of action potentials

2. The release of neurotranmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is action potential?

A

Rapid and brief reversal of the membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Where are action potentials initiated?

A

At the axon hillock has a high concentration of voltage-gated sodium ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are voltage-gated ion channels?

A

Are proteins that respond to changes in the membrane potential by opening a channel in the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are voltage-gated potassium channels?

A

Opens in response to depolarisation and let K+ move out of the cell (down the concentration gradient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are voltage-gated sodium channels?

A

Channels that open response to a depolarisation of the membrane and let Na+ move into the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the action potential threshold?

A

The membrane potential at which voltage-gated sodium channels open, Na+ rushes in

46
Q

What is meant by a refractory period?

A

Can initiate another action potential, need a bigger stimulus for second Ag
Is a point during action potential when another action potential can be initiated BUT needs a bigger stimulus

47
Q

What is meant by the absolute refractory period?

A

Membrane potentials above 0, the voltage gated sodium channel inactivates and cannot be reactivated for another action potential

48
Q

Where do action potentials go?

A

Are initiated in the axon hillock down the axon towards the axon terminals

49
Q

How do action potentials propagate down unmyelinated neurons?

A

The action potential propagates down the axon by continuous conduction

50
Q

How do action potentials propagate down unmyelinated neurons?

A

The action potential propagates down the axon by continuous conduction

51
Q

How do action potentials propagate down myelinated neurons?

A

Propagates down the axon by saltatory conduction - speeds up action potential down the axon

52
Q

What is the Node of Ranvier?

A

No insulation points Makes the propagation of a message 10x faster (saltatory conduction)

53
Q

What is the purpose of a neurotransmiter release?

A

Allows electrical signal in the axon to be converted into a chemical signal

54
Q

What is a chemical synape?

A

A point of communication between two neurons

55
Q

What happens when an action potential reaches the presnaptic terminals?

A
  1. Action potential propagates into the presynaptic terminal
  2. Action potential opens voltage-gated calcium channels
  3. Calcium inside the terminal causes snaptoc vesicles to fuse with the presynaptic membrane and release neurotransmitter
  4. Neurotransmitter diffuses across the synaptic cleft and binds onto receptors for the neurotransmitter
56
Q

What is a postsynaptic membrane potential that is hyperpolarised called?

A

Inhibitory synapse

57
Q

What is a postsnaptic membrane potential that is depolarised called?

A

Excitably synapse

58
Q

What are the functions of the CNS?

A

Detects changes in the outside/inside environment
Controls the bodys responses to external/internal changes
Generates emotions, memories, plans and thoughts etc

59
Q

What parts of the skeleton first line of defense protect CNS?

A

Brain located in skull formed by interlocking cranial bones

* The spinal cord is enclosed within vertebral column

60
Q

What parts of the skeleton protect in the second line of defense?

A

Cranial meninges surround and protect the brain

Spinal meninges surround and protect the spinal cord

61
Q

What is the first layer in the meninges layer?

A

Dura mater - the mot superficial and the strongest and adheres to the interior surface of cranial bones

62
Q

What is the second meninges layer?

A

Arachnoid mater - below dura mater, located between the dura mater- filled with interstitial fluid

63
Q

what is the third meninges layer?

A

Pia matter - innermost membrane adheres to the surface of the brain and spinal cord

64
Q

What is the blood brain barrier?

A

Prevents the flow of many substances from the bloodstream into the interstitial fluid of the NS

65
Q

How is the blood brain barrier formed?

A

By Tight cell junctions between the endothelial cells of capillaries supplying the brain
Astrocytes also contribute to the function.

66
Q

What is the cerebrospinal fluid?

A

Clear, colourless liquid that circulates continuously through cavities in the brain and spinal cord in the subarachnoid space

67
Q

What are the three main functions of the cerebrospinal fluid?

A
  1. Mechanical protection
  2. Chemical protection
  3. Circulation
68
Q

Describe the mechanical protection function of the cerebrospinal fluid?

A

Serves as a shock absorber that protects the brain. Also allows brain to float

69
Q

Describe the chemical protection function of the cerebrospinal fluid

A

Provides optimal chemical environment for neural function

70
Q

Describe the circulation function in protection of the cerebrospinal fluid

A

Provides a medium for the exchange of nutrients and wastes between the blood and nervous tissue

71
Q

How is CSF circulated

A

Filled with CBF, these ventricles are connected by narrow ducts that allow the circulation of CBF through these connected ventricles

72
Q

How is CSF circulated

A

Ventricles are connected by narrow ducts that allow the circulation of CBF through these connected ventricles

73
Q

What cells produce CBF?

A

Ependymal cells which form the CSF by filtering the blood plasma

74
Q

Where is CSF produced?

A

Formed at sites call choriod plexuses - these are a network of capillaries in the walls of the ventricles

75
Q

What is the midbrain function?

A

Motor control, visual and auditory processing, consciousness

76
Q

What is the pons function?

A

Relay from cerebrum to cerebellum, regulation of respiration and autonomic functions

77
Q

What is the Medulla function?

A

autonomic functions of breathing, heart rate, blood pressure, vomiting

78
Q

Describe the Cerebellum

A

Automatic processing centre that monitors proprioceptive, visual, balance.

  1. Maintains balance
  2. Refines movements at conscious and subconscious levels
79
Q

What is the Diencephalon?

A

Mainly thalamus relay system for sensory from cerebral cortex and hypothalamus links the nervous and endocrine system

80
Q

What are two major parts of the Cerebrum?

A

The cerebral cortex - grey matter (cell bodies)

White matter tracts (myelinated axons)

81
Q

Define Cerebral cortex

A

Conscious thought, memory storage and processing, skeletal muscle contractions

82
Q

Define White Matter Tracts

A

Connects regions of the cerebral cortex with eachother and the rest of the brain

83
Q

What are the folds and the grooves of the cerebral cortex called?

A

folds = Gyri
deeper grooves = fissures
shallower grooves =suculi

84
Q

What is the most prominent fissure?

A

Longitudinal fissure separates the LHS and RHS cerebral hemispheres (connected by white matter called the corpus callosum)

85
Q

What are the names of the cerebral lobes and where are they located?

A

Frontal
Parietal
Temporal
Occipital

86
Q

What are the function of the cerebral cortex?

A

Sensory areas
Motor areas
Association areas- complex processing

87
Q

What are the primary sensory areas of the cortex located?

A

Primary somatic motor area

Primary somatic sensory area

88
Q

Where is the primary visual area located?

A

Occipital lobe

89
Q

Where is the primary auditory area located?

A

Temporal lobe

90
Q

Where is the primary motor area located?

A

In the frontal lobe

91
Q

What are the three main types of white matter tracts present in the brain

A

Association tracts Commissural tracts

Projection tracts

92
Q

Describe Association tract

A

project between the folds of the folds (gyri) of the same cerebral hemisphere

93
Q

Describe Commissural tracts

A

Axons that project from gyri from LHS to RHS hemisphere:

  1. The corpus callosum
  2. The anterior commissure
  3. The posterior commissure
94
Q

Describe projection tracts

A

These contain axons that project from the cerebrum to lower parts of the brain

95
Q

What is the function of the thalamus?

A

It’s primary function is the relay and processing of both ascending sensory info and descending motor info

96
Q

What is the 6 hypothalamus’ functions?

A
  1. Controls body temp
  2. Production of hormones
  3. Regulation of emotions
  4. Regulation of eating/drinking
  5. Control body temo
  6. Regulates sleep
97
Q

What structures make up the brain stem?

A

Midbrain, Pons, Medulla oblongata

98
Q

What are the broad functions of the brainstem

A

Regulates involuntary functions such as breathing, heart rate, blood pressure and digestion

99
Q

Where is the cerebellum located and what does it do?

A

Evaluates voluntary movements of skeletal muscle, important in maintaining posture and balance. (back brain)

100
Q

What is the external structure of the spinal cord

A

Grey and white matter

101
Q

What is the interal structure of the spinal cord?

A

Encased in meninges, pia mater, arachroid mater, dura mater

102
Q

What is the name of the superior enlargement of the spinal cord?

A

Cervical enlargement - thickening of spinal cord

103
Q

What is the inferior enlargement of the spinal cord

A

Lumbar enlargement

104
Q

What is the name of the conical portion at the inferior end of the spinal cord?

A

Conus medullaris

105
Q

What are the spinal nerve roots?

A

The points where bundles of axons that make up spinal nerves connect with spinal cord

106
Q

What are the spinal nerve roots?

A
  1. Posterior (dorsal ) root

2. Anterior (ventral) roots

107
Q

Where are the cell bodies of sensory axons located?

A

The doral root ganglia (a swelling of the nerve root)

108
Q

What types of axons are in the anterior roots?

A

Axon of motor neurons

109
Q

What is the name given to the grey matter on each side of the spinal cord

A
  1. Posterior horn contains inter neurons and axons of sensory neurons
  2. Anterior horn contains
110
Q

What is the function of the spinal cord?

A
  1. The propagation of nerve impulses from the brain to the body, and from the body to the brain
  2. The integration of sensory and motor information