Respiration Flashcards

1
Q

Static transmural pressures

A

Difference between alveolar pressure and inter pleural pressure

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

What does compliance of the lung depend on and how?

A

Volume- low vol- high compliance

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

How does fibrosis effect compliance?

A

Same change in pressure results in small change in vol

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

How does emphysema effect compliance?

A

Same change in pressure results in big change in vol

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

How do emphysema and fibrosis effect FRC?

A

Emphysema- increase Fibrosis- decrease

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

Components of elastic recoil in the lungs

A

Elastic nature of cells, ECM and surface tension

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

What does Laplace’s equation mean in the lungs?

A

pressure in the larger sacs is lower the smaller sacs so air will flow into larger sacs from small causing them to collapse

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

Under laminar flow the movement of air in and out of lungs is proportional to what?

A

The pressure gradient and inversely proportional to the resistance

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

Equation for movement of air

A

V= change in pressure / resistance

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

Under turbulent conditions the rate of gas movement is proportional to what?

A

The square root of the pressure difference

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

What is Reynolds number?

A

2rvp/ n

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

What are the units for airway resistance?

A

cmH20.s.litres

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

What happens in emphysema?

A

Loss of elastic tissue and break down of alveolar wall, tethering between walls adjoining airspaces is reduced, flimsy airways

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

What is flow rate going up dependant on?

A

Dependant on effort

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

What is flow rate going down dependant on?

A

Not Dependant on effort

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

What does COPD cause at a given volume?

A

Airway resistance is higher

17
Q

What happens in the Gs pathway?

A

Gs activated, stimulates AC, cAMP, PKA, which acts on IP3 receptor decreasing its sensitivity to IP3 which reduces MLCK, it also phosphorylates MLCP which stimulates the phosphatase, As subunit stimulates potassium channels so hyperpolarise the cells membrane reducing calcium influx via Cav

18
Q

What receptors act through the Gs pathway?

A

B2 adrenergic receptors, VIP receptors

19
Q

What happens in the Gi pathway?

A

Activation of Gi receptors leads to inhibition of Adenylate cyclase- so counteracts the stimulatory effects of Gs, inhibits BK channel

20
Q

What receptors act through the Gi pathway?

A

M2 muscarinic

21
Q

What does histamine do to bronchial smooth muscle?

A

Constriction

22
Q

What receptors does parasympathetic control work through?

A

M3 (contraction) and M2 to stop over contraction - on the presynaptic for negative feedback

23
Q

What receptors does sympathetic control work through?

A

B2 adrenergic

24
Q

What is the asthma response?

A

Movement of inflammatory cells into airways, release of inflammatory mediatory causing bronchoconstriction

25
Q

What activity is asthma associated with?

A

Increase in parasympathetic activity on M2 receptor

26
Q

Give examples of animal experiments showing M2 is effected in asthma?

A

Antigen challenge, virus, vitamin A deficient, ozone exposure

27
Q

What is antigen challenge?

A

Change in M2 function linked to eosinophils, eosinophils clusters around nerve fibres and release major basic protein which inhibits M2

28
Q

How do anticholinergics treat asthma?

A

Block effects of Aah- actions mainly via M1 and M3 receptors

29
Q

Give an example of an anticholinergic.

A

Tiotropium bromide

30
Q

How do glucocorticoids treat asthma?

A

Anti-inflammatory actions, activated GRE and reduces inflammatory genes and reduces mRNA instability

31
Q

What nerve match the pre-botzinger complex output? how is this known?

A

Hypoglassal (12th cranial nerve). Brain slices taken and do electrophysiology

32
Q

What are the 2 centres in the pons and what do they do?

A

Pneomotaxic- Inhibits respiratory to reduce rate

Apneustic - stimulates respiratory centres to increase rate and depth

33
Q

How does the Hering- breur reflex happen?

A

Stretch receptor- vagus nerve-inhibitory centres-phrenic nerve-diaphragm