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Flashcards in Week 1 Deck (91):
1

What part of the neurone receives inputs from other neurones and convey graded electrical signals passively to the soma?

Dendrites

2

What is the synthetic and metabolic centre of the nuerone?

Soma - integrates incoming signals that are conducted passively to the axon hillock

3

Where in a neurone is the site of initiation of the all or none action potential

Axon hillock and initial segment

4

What part of a neurone conducts output signals as actin potentials to other nuerones, mediates transport of materials between the soma and presynaptic terminal and vice versa?

Axon

5

What things exploit retrograde transport to infect neurones?

Several viruses

6

Give an example of a unipolar neurone?

Peripheral autonomic neurone

7

Give an example of a pseudounipolar neurone?

Dorsal root ganglion neurone

8

Give an example of a bipolar neurone?

Retinal bioplar neurone

9

Give an example of a multipolar neurone?

Lower motor neurone

10

What has a constant amplitude?

Action potentials

11

What does the distance over which current spread depend on?

Mmebrane resistance and axial resistance of the axoplasm

12

What provides myelin in the PNS?

Schwann cells

13

What provides myelin in the CNS?

Oligodendrocytes

14

What is the term given for when AP leap from one node of ranvier to the next?

Saltatory conduction in myelinated axons

15

What is the most common type of synapse?

Axodendritic

16

What two classifications do synapses fall into?

Inhibitory and excitatory

17

What is the transmitter in excitatory synapses?

Glutamate

18

What is the transmitter in inhibitory synapses?

Glycine. aminobutyric acid (GABA)

19

What transmitter activates cation ( positive) selective receptors?

Glutamate

20

What transmitter activates anion selective receptors?

Glycine, GABA

21

Name the three major amino acid neurotransmitters in the CNS?

Glutamate, GABA and glycine

22

What are released from synaptic esicles?`

Amino acids and amines

23

What are released from secretory vesicles?

Peptides

24

What do GABA and amines require to be synthesised by the neurones specifically?

Specific enzymes

25

What direction do K channels flow?

Outwards of cells (hyperpolarisation, inhibitory)

26

What shape are glutamate receptor channels?

Tetramers

27

What shape are GABA, glycine and nicorinic ACh gates channels?

Pentamers

28

What is the role of metabotropic glutamate receptors?

Modulation of neurotransmission (e.g. presynaptic inhibition (inhibition of Ca channels))

29

What channel is operated in ionotropic GABA a receptors?

Cl channels

30

What channel is operated in metabotropic GABA b receptors?

Potassium channel

31

Which is slower - ionotropic receptors or metabotropic (gprotein couples) receptors?

Metabotropic

32

Because the slow actions of metabotropic receptors (gprotein couples) cannot trigger APs - what do they do instead

Modulate synaptic actions

33

In relation to a graded potential - what can increase the amplitude and allow it to travel further?

Soidum

34

Give an example of a strategy to increase quantal (neurotransmitter) release - extensive innervation?

Purkinje cell - inferior olivary neuron synapse

35

In relation to the somatosensory system: what do low threshold units respond to?

Low intensity - non-damaging and non-painful stimli

36

In relation to the somatosensory system: what do high threshold units (nociceptors) respond to?

High (noxious, potentially damaging) stimuli

37

What response do strethc receptors give?

Slow adapting tonic/static

38

What response does hair follicle afferents give?

Rapidly adapting phasic/dynamic

39

What type of axon from skin is thick and involved in proprioceptors of skeletal muscles?

A-alpha

40

What type of axons from skin are mechanoreceptors of skin?

A-beta

41

What type of axons from skin are pain, temperature?

A-delta

42

What type of axons from skin are temperature, pain and itch?

C

43

What term is given to the region that when stimulated with adequate stimulus causes a response in that afferent neurone?

Receptive field

44

What can be said about regions with the highest discriminative capacity?

They have the smallest receptive fields (finger tips)

45

Where are krause end bulbs found?

At the border of dry skin and mucous membranes

46

Where are ruffini endings found?

Within dermis and also joint capsules

47

What fibre group is C mechanoreceptor involved in stroking, social and erotic touch?

Fibre group C

48

What name is given to the area of skin innervated by the left and right dorsal roots of a single segment?

Dermatome

49

What is shingles due to infection of?

Dorsal root ganglion neurones

50

What fibre class are nociceptors and where do they terminate?

A-delta/C
Terminate in laminae I and II

51

What fibre class are LTMs and where do they terminaste?

A-beta
Terminate in laminae III - IV

52

What fibre class are proprioceptors and where do they terminate?

A-alpha
Terminate in laminae VII - IX

53

In the dorsal column medial leminscal pathway - (proprioception [Aalpha] and mechanoreceptors [Abeta]) where does decussation occur?

Brainstem

54

In the spinothalamic tract (pain, thermosensation [c/delta]) where does decussation occur?

At all levels of spinal cord, close to point of entry

55

What does the dorsal column consist of?

Medial fasciculus gracilis and lateral fasciculus cuneatus

56

What dorsal column does sesnsory input to T6 and below travel in?

Medial fasciculus gracilis

57

What dorsal column does sensory input to above T6 travel in?

Lateral fasciculus cuneatus

58

Whast is the major route in which touch and proprioceptive information ascents to the cerebral cortex?

Dorsal column medial lemniscal

59

What is general somatic information from the anterior head mediated by?

Two trigeminothalamic pathways

60

Central terminals of the trigeminal nerve sypnase upon second order neurones in what two nuclei?

Chief sensory - general tactile stimuli
Spinal nucleus - pain, temperature

61

Once central terminals of trigeminal nerve have synpased on either chief sensory nucleus or spinal nucleus - they then decussate and project where?

To the ventroposteriomedial nucleus of the thalamus

62

What is located in the post central gyrus of the parietal cortex, immediately posterior to the central sulcus and adjacent to the posterior parietal cortex?

The somatosenosry cortex (SI)

63

What Brodman areas make up the somatosensory cortex?

1, 2, 3a and 3b

64

What does the somatosensory cortex receive input from?

The VP thalamus

65

In the somatosensory cortex - what inputs into BA 3a?

proprioceptors (muscle spindles)

66

In the somatosensory cortex - what inputs into BA 3b?

Cutaneous and RA receptors (touch

67

In the somatosensory cortex - what inputs into BA 1

Cutaneous RA mechanoreceptors (texture discrimination)

68

In the somatosensory cortex - what inputs into BA 2

Joint afferents, golgi tendon organs, deep tissues (object perception)

69

What does scaling the body surface to the volume of SI cortex devoted to hte representation of a body part give rise to?

Homunculus

70

What do adjacent strips of the somatosensory cortex map?

The same parts of the body in parallel to eac other. Maps are mirror images of each other

71

If a finger (D3) is amputated what happens to the area of somatosensory cortex representing the finger?

Utlised by other sensory inputs such as adjacent digits D2 and D4

72

What cortex receives and integrates information from somatosensory cortex and other cortical areas (visual, auditory) and subcortical areas (thalamus)?

Posterior parietal cortex

73

Damage to the right parietal cortex can cause what syndrome?

Neglect syndrome

74

What are the three types of pain?

1. Sensory - discriminative
2. Cognitive - evaluative
3. Affective - emotional

75

What is the difference between nociceptive pain and neuropathic pain?

Nociceptive - appropriate physiologic response to painful stimuli
Neuropathic - inappropritate response caused by a dysfunction in nervous system

76

Give a few causes of neuropathic pain?

1. Shingles
2/ Surgery
3. Diabetic neuropathy

77

Name two non-opiod analgesics?

NSAIDS
Paracetamol

78

Name 4 opiod analgesics?

1. Tramadol
2. Codeine
3. Morphine
4. Oxycodone

79

Name two antidepressant adjucants?

Amytriptyline
Duloxetine

80

Name two anticonvulsant adjucants?

1. Gabapentin
2. Pregabalin

81

Name two topical analgesic adjucants?

Capsaicin
Lidocaine 5% plaster

82

What type of pain do non-opid analgesics act on?

Nociceptive pain

83

How do non-opiod analgeiscs (NSAIDS) work?

Inhibition of cyclooxygenase and prostaglandin synthesis decreases

84

What type of pain do opiod analgeiscs act on?

Nociceptive, only partially effective in neuropathic pain

85

Name some side effects of weak opiods?

Nausea, vomiting, constipation, dizziness, somnolence, dry skin and itch

86

What type of pain are antidepressants used for?

Neuropathic - CRPS, tension headache

87

How do antidepressants work for pain?

Inhibition of neuronal reuptake of noradrenaline and serotonin (5-HT)

88

Name some side effects of antidepressents?

Constipation, dry mouth, somnolence, heart rate, insomnia, increased appetite

89

What type of pain are anticonvuldsants used for?

Neuropathic pain

90

Some side effects of anticonvulsants?

Sedation, dizziness, ataxia, peripheral oedema, nausea, weight gain

91

What do topical analgesics reduce pain impulses transmitted by?

A-delta fibres
C-fibres