Respiratory System Flashcards

(54 cards)

1
Q

Why study neural respiratory control?

A
  • respiratory neurons generate a most important rhythm pivotal for oxygen supply for energy utilization (apnea and fentanyl crisis)
  • treatment of respiratory-related disease (sleep apnea. SIDS, AOP, CCHS)
  • model for structure-function relation of neural networks (respiratory networks remain active in vitro –> easy to study)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an easy way to measure inspiratory rhythm?

A

EMG electrodes attached to genioglossus mm in TONGUE

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

Why do we record EMG activity from the genioglossus muscle to assess inspiratory rhythm?

A
  • genioglossus mm CONTRACTS during inspiration to maintain/keep upper airways (pharynx) open
  • genioglossus mm innervated by CN XII hypoglassal nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which cranial nerve is associated with inspiratory rhythm?

A

CN XII hypoglossal nerve

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

What are the 3 major medullary respiratory groups?

A
  • pontine (PRG)
  • dorsal (DRG)
  • ventral (VRG)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which respiratory group contains inspiratory neurons?

A

PRG, DRG, VRG

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

Which respiratory group contains ONLY inspiratory neurons?

A

DRG

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

Which respiratory group contains expiratory neurons?

A

PRG, VRG

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

Which respiratory group contains both expiratory and inspiratory neurons?

A

PRG and VRG

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

Which respiratory group contains ONLY expiratory neurons?

A

none

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

In which brains structures of the PRG, DRG, and VRG found?

A
  • PRG in DORSAL pons
  • DRG in DORSOMEDIAL medulla
  • VRG in VENTRAL medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the reference point for the location of respiratory neurons?

A

obex (opening of the 4th ventricle)

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

Which respiratory group’s neurons belong to the NTS?

A

DRG

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

Which respiratory group is important for sensory integration of respiratory activity?

A

PRG and DRG

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

Which respiratory group is important for generating the primary rhythm?

A

VRG

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

What is the most important respiratory muscle?

A

diaphragm

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

Contraction of the diaphragm causes a/an ______________ in the volume of the ribcage. (increase/decrease)

This induces the _____________ phase of breathing. (inhalation/exhalation)

A

increase; inhalation

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

TRUE or FALSE: during normal breathing, exhalation is caused by contraction of the diaphragm.

A

FALSE: exhalation occurs PASSIVELY

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

What is exhalation mediated by in normal breathing?

A

recoil force of the tendons attached to the respiratory muscles (PASSIVE)

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

Which muscles are activated during active expiration?

A

abdominal muscles: rectus abdominus, external oblique, internal oblique, transverse dominus

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

Which muscles are activated during normal expiration?

A

internal intercostals

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

Which muscles are activated during inspiration?

A

external intercostals

23
Q

Which respiratory group drives the respiratory muscles?

24
Q

Which nerve innervates the diaphragm?

A

phrenic nerve

25
What are the 3 phases of respiratory rhythm?
1. inspiratory (I) 2. pot-inspiratory (PI) 3. active expiratory (E2)
26
Which nerve is active during inspiratory rhythm? expiratory rhythm?
- inspiratory = phrenic nerve - expiratory = intercostal nerve
27
TRUE or FALSE: activation of the phrenic nerve stops abruptly after the inspiratory phase.
FALSE: activation increases during inspiratory phase and slowly declines during post-inspiratory phase
28
TRUE or FALSE: the phrenic nerve becomes silent during the E2 phase
TRUE
29
Which level of the spinal cord innervates the phrenic nerve? Which muscle does this nerve innervate?
- C3-C6 - diaphragm mm
30
Which level of the spinal cord innervates the thoracic to intercostal nerve? Which muscle does this nerve innervate?
- T1-T2 - intercostal mm ( internal for expiratory)
31
In a diagram, demonstrate the activity of the phrenic nerve vs the intercostal nerve during the 3 respiratory rhythm phases.
slide 4
32
Which substance blocks GABAa receptors? glycine receptors?
- bicuculline blocks GABAa - strychnine blocks glycine receptors
33
Respiratory neurons in newborns already show IPSPs that cause hyperpolarization. What does this indicate?
respiratory network is ALREADY MATURE AT BIRTH, unlike hippocampal and cortical neural networks in which GABA and glycine evoke spontaneous rhythmic DEPOLARIZATIONS
34
Within the VRG, what area is critical for rhythm generation in respiration?
pre-Botzinger complex
35
TRUE or FALSE: the pre-botc is very thin
TRUE
36
what kind of respiratory rhythm does the pre-BotC generate?
inspiratory
37
TRUE or FALSE: preBotC neurons excite expiratory neurons and inhibit inspiratory neurons during the expiratory phase.
FALSE: excite inspiratory neurons, inhibit expiratory neurons during inspiratory phase
38
TRUE or FALSE: mainly inspiratory neurons are found in the pre BotC
TRUE
39
Which cranial nerve is related to inspiratory activity?
CN XII (hypoglossal) (hint: record activity of genioglossus muscle shows)
40
Inspiratory active pre-BotC neurons show rhythmic cytosolic Ca2+ ____________ (rises/falls) due to their rhythmic rhythmic ____________ (depolarizations/hyperpolarizations).
rises; depolarizations
41
How does the addition of TRH affect Ca2+ enhanced inspiration in sighing?
Ca2+ rises are very regular and uniform, showing only eupnea-like inspiratory events
42
What does a eupnea-like vs inspiratory sigh look like in terms of Ca2+ rises?
- eupnia: small amplitude - sigh: large amplitude
43
What is eupnea?
normal inspiration
44
TRUE or FALSE: rhythm generation depends on mutual inhibition
FALSE: rhythm generation does NOT depend on mutual inhibition
45
How are we able to determine that the inspiratory rhythm does not depend on GABAa and glycine receptors?
when strychnine and bicuculline are administered in VRG neurons, inspiratory bursting is not inhibited
46
Describe the emerging network model of pre-botC rhythm generation.
1. post-burst hyperpolarization: synapses silent (end of PI) 2. recovery: endogenous activity resumes (some rhythmogenic neurons activate) 3. recurrent excitation: positive feedback (rhythmogenic neurons stimulate their neighbours) 4. burst: synaptic excitation evokes intrinsic currents (cycle back to 1)
47
TRUE or FALSE: inspiratory neurons are dependent on GABAergic neurons
FALSE: dependent on glutamatergic neurons
48
What are the 2 respiratory centers that make up the dual respiratory center in mammals? Which one is inspiratory/excitatory?
- preBotC = inspiratory - RTN (retroptrapezoid nucleus)/pFRG (parafacial respiratory group) = expiratory
49
Why is the expiratory center often named RTN/pFRG?
pFRG area fully overlaps with RTN area which contains chemosensitive respiratory and non-respiratory neurons
50
during which phase is pFRG active?
post-inspiratory phase
51
TRUE or FALSE: opioids block inspiratory but not expiratory rhythm.
TRUE
52
How does fentanyl affect abdominal muscle activity vs inspiratory-related airflow?
- abdominals: regular pre-inspiratory bursting - airflow: slowed down
53
which substance kills pre-BotC neurons that express NK1 subtype of substance P receptors? How does it affect breathing? When does it affect breathing?
- saponin (SAP) - depresses inspiration during REM sleep
54
TRUE or FALSE: NK1 receptor-expressing pre-BotC neurons are important for rhythm generation.
TRUE