Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BDS1 > Locomotor - Dr Hughes > Flashcards

Locomotor - Dr Hughes Flashcards

1
Q

Describe the structure of a sensory nerve cell

A

Pseudounipolar Neuron:
Cluster or peripheral nerve branches with nerve receptor ending at peripheral ending
Single axon from cell body, which bifurcates
Axon terminus in CNS

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

Name the sensory receptors (8)

A

mechanical, sound - Mechanoreceptor - touch and hearing
chemical - Chemoreceptor - smell, taste
noxious - Nociceptor - pain
limb position - Proprioceptor - spatial awareness
blood pressure - Baroreceptor
light - Photoreceptor - sight, vision
thermal - Thermoreceptor - hot, cold

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

What is a receptive field?

A
  • Each neuron, has a cluster of peripheral nerve branches, each with a nerve ending
  • the distribution of these receptors defines a receptive field
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where has a larger receptive field?

A

Trunk

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

Where has a small receptive field

A

Periphery, tip of fingers

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

What is two point discrimination a measure of?

A

1) Spatial resolution

2) Size of receptive field

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

What would a small 2-point discrimination indicate?

A

1) Large cortical representation

2) Small receptive field

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

*Describe the transduction of sensory stimuli

A 
Stimuli ->
Change in receptor membrane permeability ->
influx of cations->
Depolarization: receptor potential ->
AP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describes transduction of stimuli in mechanoreceptors

A

Mechanical force ->
Deformation of cell membrane ->
Causing opening of channel (via strand/tether ?) ->
Movement of Na+/K- through channel

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

How are chemoreceptors activated?

A

1) via ionotropic (ligand-gated ion channels) - fast

2) via G-protein coupled channels - slows

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

How is sensory information coded?

A

Stimulus Coding
Quality Type of receptors
Intensity Frequency of AP (diff. thresholds)
Number of neurons activated
Duration Duration of AP firing - kick to shin
Location Where - homunculus

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

Why type of axon do proprioceptors of skeletal muscles use?

A

Aα

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

What type of axons do mechanoreceptors of skin use?

A

Aβ

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

What type of axons do pain and temperature receptors use?

A

Aδ

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

What type of axons do temperature, pain and itch receptors use?

A

C

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

In the neural pathway, what are receptors?

A

peripheral endings of sensory neurons

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

Give examples of modality specific pathways

A

touch, pain, vision

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

Where do pathways terminate in the brain?

A

Primary receiving areas

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

How many spinal nerves are there?

A

31 pairs

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

Give examples of cutaneous and subcutaneous mechanoreceptors (Aβ afferents) (5)

A 
Meissner's corpuscle
Merkel disk
Hair follicle receptor
Pacinian corpuscle (vibration and slippage)
Ruffini's ending (same)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What type of innervation does a peripheral nerve have?

A
  • Sensory only axons and

- Motor and sensory axons

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

What does the Brachial Plexus innervate? (5)

A

The upper limb (C5, C6, C7, C8, T1)

  1. Axillary
  2. Musculocutaneous
  3. Radial
  4. Ulna
  5. Median
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the outer layer of a peripheral nerve called

A

Epineurium

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

What is a bundle of nerves called?

A

Fascicle (Fasciculi)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
In a peripheral nerve, what are the sections surrounding the fascicle called
Perineurium
26
Other then axons, what else might the peripheral nerve contain?
Blood vessels
27
What is the diameter and speed of the Aα axon?
13 - 20 µm | 80 - 120 m/sec
28
What is the diameter and speed of the Aβ axon
6- 12 µm | 35 - 75 m/sec
29
What is the diameter and speed of the Aδ axon
1 - 5 µm | 5 - 30 m/sec
30
What is the diameter and speed of the C axon
0. 2 - 1.5µm | 0. 5 - 2 m/sec
31
Sensory axons enter the CNS via...?
Dorsal roots
32
Where are cell bodies of sensory axons located?
dorsal root ganglia
33
Motor axons exit the CNS via...?
Ventral roots
34
What does the trigeminal nerve innervate
V1 - Opthalmic (sensory) V2 - Maxillary (sensory) V3 - Mandibular (sensory and motor)
35
Describe the sensory pathway
1st neuron : primary sensory neuron, periphery 2nd neuron: secondary sensory neuron, CNS 3rd neuron: tertiary sensory neuron, thalamus -> cerebral cortex
36
Describe the mechanoreception/ somatic pathway
Dorsal column medial lemniscal pathway
37
Describe the mechanoreception/ trigeminal nerve
Posterior (Dorsal) Trigeminothalamic tract
38
Describe the nociception/ somatic pathway
Spinothalamic pathway
39
Describe the nociception / trigeminal nerve
Anterior (ventral) trigeminothalamic tract
40
Where is the visual centre in the brain?
Occipital lobe
41
Where is the auditory centre of the brain?
Temporal lobe
42
Where is the taste centre of the brain?
Parietal lobe (Primary Gustatory Cortex is located near the face area of the somatosensory cortex)
43
In the sensory homunculus, which areas are represented more widely in the cortex?
- Areas with a high density of receptors ( ie. with a small receptor field) are represented more widely in the cortex.
44
What is Stereognosis?
The ability to recognise objects by the feel alone.
45
What does sterognosis require?
Memory: - requires a 3-D mental image - need to compare to previous experiences
46
What is involved in proprioception?
``` 1) Balance organs in inner ear Utricle, saccule, semicircular canal Head posture, overall balance 2) Joint receptors Join position, angle 3) Muscles receptors Muscle length, tension 4) Periodontal receptors Tooth contact, bite force ```
47
What is the difference between pain and nociception?
``` Pain = sensation Nociception = neural process from receptor -> CNS -> sensory cortex ```
48
What is pain?
An unpleasant SENSORY and EMOTIONAL experience associated with actual or potential tissue damage, or described in terms of such damage
49
How is pain classified?
1) Nociceptive pain 2) Clinical pain - Acute - Chronic
50
What are the axons for pain
Aδ and C
51
When is nociceptive pain elicited?
When intense/noxious stimuli threatens to damage normal tissue
52
How is nociceptive pain characterised
high threshold and limited duration
53
What is the function of nociceptive pain?
adaptive/biologically useful - serves as a protective function
54
What are the characteristics of acute clinical pain?
- protective factor | - from soft tissue injury/ inflammation
55
what are the characteristics of chronic clinical pain?
- sustained sensory abnormality - result of on going peripheral pathology e.g. chronic inflammation, peripheral nerve injury - maladaptive - spontaneous or provoked e.g allodynia - resistant to treatment
56
How many pairs of cervical spinal cords are there?
8
57
How many pairs of thoracic spinal cords are there?
12
58
How many pairs of lumbar spinal cords are there?
5
59
How many pairs of sacral spinal cords are there?
5
60
How many pairs of coccygeal spinal cords are there?
1
61
What order are the spinal cords?
``` Cervical Thoracic Lumbar Sacral Coccygeal ```
62
Where does pain tend to be referred?
common embryological origin | internal organ to superficial area e.g. skin
63
Why does pain tend to refer
convergence of inputs in the CNS
64
Name some surface areas of referred pain
``` Heart: Left arm and chest Oesophagus: upper chest, left arm stomach: Liver and gallbladder: Appendix and small intestine Ureter ```
65
What are the characteristics of nociceptor nerve endings?
Free nerve endings High threshold respond to intense/noxious stimuli usually associated with pain A alpha - noxious mechanical/ heat C - polymodal carry several types of receptors proteins display sensitisation
66
What does the spinal lemniscus consist of?
Medulla, pons, midbrain
67
In the pain pathway, what are the CNS relay cells
spinal dorsal horn | spinal trigeminal nucleus
68
What are the CNS pain pathways
Spinothalamic pathway | anterior trigeminothalamic tract
69
Where does the ascending pain pathway terminate in the forebrain?
Primary sensory cortex subcortical areas
70
Where are the nociceptive afferents in the teeth
Free nerve endings extend into the dentine
71
What factors affect pain perception?
``` Genetic molecular cellular anatomical physiological Psychological Social ```
72
What does SCN9A encode for
alpha- unit of voltage-gate NA+ channel NAv1.7
73
What factors are involved Pain Psychology
Situation factors Emotional factors Psychological factors
74
What are some of the ways of modulating pain?
``` "in built" complementary medicines Psychology/ Cognitive BT Sex Age Pharmacology Surgical Genetic Environment ```
75
What is the gate control theory of pain?
Pain can be reduced by activating a non painful sensation. 1) C or A delta fibres transmit pain signals from the periphery 2) the projection neuron transmits pain signals to the sensory cortex = pain 3) A beta fibres transmit mechanical stimulation impulses to the sensory cortex via the dorsal column medial lemniscus 4) the mechanical stimulus activates the inhibitory neurons which inhibit the projection neuron to limit pain,
76
What are the important areas
The descending pathway controls and inhibits the ascending pathway - only active in certain situations
77
What contributes to the modulation of nociceptive afferent input
Supraspinal loop
78
What anatomical features are involved in the modulation of nociceptive input?
Descending pain modulating circuit feed to - Midbrain, periaquaductal grey matter (PAG) goes to -Medula neurons within nucleus raphe magnus goes to - spinal cord/ dorsal horn
79
Describe the modulation of nociceptive input
It is a pain inhibitory system: Pon PAG -> Medulla Raghe: 5HT and NA descending projections. - > direct inhibition of projection neurons - > activation of enkephalin - containing interneurons ("endorphin" release: edogenous opioids) - > reduces activity in nociceptive circuits
80
What are the 3 parts of the triple reaction?
1) Red line 2) Wheal - odema 3) Flare
81
Describe the reaction in the triple reaction
Tissue damage -> K+ + prostaglandins released activators for receptive endings in nociceptive terminals Plasma : release bradykinins Platelets: release 5TH Spinothalamic pathway activated Also, receptive endings in skin release CGRP + Sub P CGRP + Sub P activate local mast cells Local mast cells degranulate and release histamines Histamines acts on the receptive endings to reinforce that there is trauma within the region CGRP cause dilation of blood vessels Sub P cause plasma extravasation and oedema, and release bradykinin
82
What is the name of an extreme case of triple response
Dermatographia

BDS1 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions