Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Semester 3 > PBL 2 > Flashcards

PBL 2 Flashcards

1
Q

Considering A alpha afferent nerve fibres, state their:

  • Cell body diameter
  • Unmyelinated or myelinated
  • Nerve conduction speed
  • sensory modalities
A
  • Large cell body diameter
  • Myelinated
  • Fast nerve conduction speed
  • proprioception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Regarding A delta afferent nerve fibres state their:

  • Cell body diameter
  • Unmyelinated or myelinated
  • Nerve conduction speed
  • sensory modalities
A
  • small/medium cell body diameter
  • thinly myelinated
  • medium conduction speed
  • high threshold mechanoreception (pain and temperature)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Regarding C type afferent nerve fibres state their,

  • Cell body diameter
  • Unmyelinated or myelinated
  • Nerve conduction speed
  • sensory modalities
A
  • small cell body diameter
  • unmyelinated
  • slow conduction speed
  • pain and temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two types of nociceptor fibres and what kind of pain do they carry?

A

A delta fibres - carry sensations of fast sharp pain

C fibres - carry sensations of slow burning and aching pain

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

Name the 4 types of tactile mechoreceptors and what they are sensitive to.

A

Merkel’s Discs - fine touch and pressure
Meisenner Corpuscle - fine touch, pressure, low frequency vibration
Pacinian Corpuscle - deep pressure
Ruffini ending - internally generated stimuli

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

Considering A beta afferent nerve fibres, state their:

  • Cell body diameter
  • Unmyelinated or myelinated
  • Nerve conduction speed
  • sensory modalities
A
  • Large cell body diameter
  • Myelinated
  • Fast nerve conduction speed
  • proprioception and low threshold mechoreception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are Golgi tendon organs?

A

Type of sensory receptor cell that monitor proprioception. Located between a skeletal muscle and its tendon. They inform the CNS about changes in tension during a muscle contraction.

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

What are the two main Ascending Tracts?

A 
Spinothalamic (ventral/anterior and lateral)
Dorsal columns (fasiculus gracilis and fasiculus cuneatus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What kind of sensory modalities does the lateral spinothalamic tract carry?

A

Pain and temperature

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

What kind of sensory modalities does the ventral spinothalamic tract carry?

A

Crude touch and pressure

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

What is the spinothalamic pathway?

A

1st order neruon - periphery to dorsal horn of spinal cord
2nd order neuron - Dorsal horn, crosses white matter commissure to reach contralateral spinothalamic tract, ascends to VP thalamus
3rd order neuron - VP thalamus to sensory cortex

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

What is the Dorsal Column Pathway

A

1st order neuron - periphery to dorsal horn, ascend ipsilaterally to the medulla
2nd order neuron - decussate in medulla, ascend to sensory portion of thalamus (VPL nucleus of thalamus)
3rd order neuron - VPL of thalamus, posterior limb of internal capsule, primary somatosensory cortex

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

What sensory modalities do the dorsal columns carry?

A

Precise touch, vibration and proprioception

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

What are the internal arcuate fibres and medial lemniscus?

A

Internal arcuate fibres - 2nd order neurons axons that compose the dorsal column nuceli (nucleus gracilis/nucleus cuneatus)

Medial lemniscus - 2nd order neurons from dorsal columns that ascend from the medulla to the VPL of thalamus

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

Describe the pathway of the lateral corticospinal tract

A

1st order neuron - arise in motor cortex, descend in posterior limb of internal capsule, and reach the medulla. At the medulla they decussate and descend down the lateral corticospinal tract to the anterior grey horns
2nd order neuron - arises in grey horns and projects to muscle

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

Describe the pathway of the ventral corticospinal tract

A

1st order neuron - arise in motor cortex, descend in posterior limb of internal capsule, and reach the medulla. At the medulla descend ipsilaterally down the ventral corticospinal tract to the spinal cord, decussate at level of spinal cord, terminate in anterior grey horns
2nd order neuron - arises in grey horns and projects to muscle

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

Describe the sensory pathway in cranial nerves

A

1st order neuron - come ipsilaterally from periphery and synapses with trigeminal sensory nucleus in the brainstem
2nd order neuron - originates from trigeminal sensory nucleus and decussates before ascending to the VP thalamus
3rd order neuron - arises in the thalamus and ascends to sensory cortex

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

What are the 4 cranial nerves that have 1st order neurons that bring sensory information into the spinal cord?

Also what and where are their ganglia in the periphery?

A

Trigeminal nerve - trigeminal ganglion (meckel’s cave in petrous part of temporal bone)
Facial nerve - geniculate ganglion (facial canal)
Glossopharngeal and Vagus - superior ganglia (middle part of jugular foramen) and inferior ganglia (on level of 1st vertebrae)

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

What are the 3 subnuclei within the trigeminal sensory nucleus?
Where on the brainstem are they located?
What modalities do they sense?

A

Mescencephalon - midbrain, proprioception
Chief sensory - pons, touch and pressure
Spinal - medulla oblongata, pain and temperature

20
Q

What is the main motor pathway called for cranial nerves?

A

Corticobulbar

21
Q

Which cranial nerves receive bilateral motor innervation?

A

III, IV, V, VI, IX, X, XI

22
Q

Which cranial nerve receives contralateral innervation?

A

Hypoglossal (CN XII)

23
Q

Describe the motor innervation of the facial nerve?

A

Upper part - bilaterally innervated

Lower part - contralaterally innervated

24
Q

Which cranial nerves have parasympathetic innervation?

A

Occulomotor
Facial
Glossopharnygeal
Vagus

25
Q

What is the difference between paravertebral and prevertebral sympathetic ganglia?

A

Paravertebral - located along the sides of vertebrae (sympathetic chain)

Prevertebral - located anterior to the abdominal aorta

26
Q

What are the 3 routes that a sympathetic preganglionic neruon can take?

A

1) Synpase in paravertebral ganglia on the same level
2) Synapse in paravertebral ganglia on a different level
3) Synpase with a prevertebral ganglia

27
Q

What is a splanchnic nerve?

A

The name of a sympathetic nerve that has synapsed with a prevertebral ganglia

28
Q

Name some factors that can activate Nociceptors

A

Archidonic acid, protein kinases, histamine, substance p, potassium, serotonin, acetylcholine, lactic acid

29
Q

What is the A delta fibre pain pathway?

A
  • Fibres arise in periphery and terminate in laminae I and V in the spinal grey matter
  • second order neurons decussate via anterior commissure and ascend through the lateral column of spinothalamic tract
30
Q

What is the C fibre pain pathway?

A
  • Peripheral fibres terminate in the substantia gelatinosa (II and III)
  • 2nd order neurons decussate through anterior commissure and ascend in the lateral spinothalamic tract
31
Q

What is hyperalgesia?

A

Heightened pain evoked by a noxious (painful) stimulus

32
Q

What is Allodynia?

A

Pain evoked by a normally innocuous stimuli

33
Q

What is parasthesia?

A

Unpleasant pain with no stimulus. Often described as burning, tightness, tingling, shooting or stabbing pain

34
Q

Explain the gate control theory of pain

A

Small fibre input (noicepetion) - activates projection neurons so can project signal to brain (gate open)

Large fibre input (normal somatosensory) - inhibits projection neurons via imnhibitory neurons in dorsal horn, so projection neuron cannot project to the brain (gate closed)

35
Q

How do endogenous opiates modulate pain pathways?

A

Act to ‘close the gate’ in the spinal cord

At at inhibitory synapses to help inhibit the projection pain neurons from getting to the brain

36
Q

What are the main types of opioid receptors?

A

Mu, delta, kappa, ORL1

37
Q

What is the mechanism of action of Opoid agonists?

A
  • Bind to G protein coupled opoid receptors e.g, mu
  • Reduce intracellular cAMP
  • open K+ channels, to reduce synaptic transmission so cell is hyperpolarised
  • inhibition of calcium channels, reduces synaptic transmission
38
Q

Name 2 opoid receptor antagonists

A

Naloxone

Naltrexone

39
Q

How do TENS machines work?

A

High pulse - triggers pain gate to close

Low pulse - stimulate production of endorphins (natural pain killers)

40
Q

What are the most common vertebral levels for a slipped disc to occur?

What nerve would they compress?

A

L4-L5: compress the L5 nerve

L5-S1: compress the S1 nerve

41
Q

How is a CT scan carried out?

A
  • X-ray beam is rotated around the patient to take many different view of a single slice of the patient
  • Digital date is then converted to cross sectional image to reconstruct anatomy
42
Q

What is the difference between a T1 weighted and a T2 weighted MRI scan?

A

T1: fluid appears dark, lipids appear bright

T2: fluid appears bright, fatty tissues appear dark

43
Q

What is the main addictive pathway in the brain?

A

Reward pathway:

VTA (ventral tegmental area) projecting dopaminergic neurons to the nucleus accumbens

44
Q

How does cocaine cause modulate the dopamine pathway?

A

It blocks VMAT transporter so dopamine cannot be taken back up, increasing the firing of neurons in the nucleus accumbens reward pathway

45
Q

How do opiates modulate the nucelus accumbens dopamine pathway?

A

Opiates act on mu receptors to decrease GABA neurons from releasing GABA. This reduces the inhibition of dopamine release. Increasing dopamine in the nucleus accumbens pathway

46
Q

What drugs are used to in replacement for opiate addiction? State their method of action.

A

Methadone - opiod receptor agonist

Buprenophine - partial opoid receptor agonist

Naltrexone - opoid antagonists - increases inhibition of GABA

Semester 3 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions