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Flashcards in PULMONARY 2.0 Deck (63)
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1
Q

Your tidal volume can increase to …

A

2.0 L or more

2
Q

When do respiratory muscles contract

A

when stimulated by their nerve supply

3
Q

Where is the primary respiratory control centre

A

the respiratory centre in the medial medulla

4
Q

What is the route of impulses to control respiratory muscles

A

From respiratory centre in medial medulla to motor neurons located in spinal cord to respiratory muscles

5
Q

What are factors that affect medullary control of pulmonary ventilation

A
  • Peripheral chemoreceptors
  • Receptors in lung tissue
  • Proprioceptors in joints and muscles
  • Core temperature
  • Chemical state of blood in medulla
6
Q

Where is the best peripheral chemoreceptor

A

in carotid artery

7
Q

What do chemoreceptors do

A

sample PO2 and PCO2 in blood as it goes by

8
Q

When do the receptors in lung tissue send signals to the brain

A

when they are stretched

9
Q

When do muscles and joints send signals to the brain

A

when there is lots of movement - to adjust breathing accordingly

10
Q

When core temp ____ it ____ breathing regulatory centres in the brain

A

increases

excites

11
Q

Upon onset of exercise there is a ____ increase in minute ventilation

A

sharp

12
Q

What occurs to breathing as you stop exercising

A

it gradually comes back down

13
Q

What occurs to minute ventilation in non-steady-rate exercise from rest to moderate

A

increases in proportion to oxygen consumption over range from rest to moderate exercise

14
Q

What occurs to minute ventilation in non-steady-rate exercise from moderate to strenuous

A

increases disproportionately to oxygen consumption

15
Q

What occurs when there is inadequate O2 delivery or utilization (series of events)

A

reliance on anaerobic metabolism -> increase lactate -> production of H2O and CO2 -> Excess, non-metabolic CO2 stimulates increased pulmonary ventilation (additional exhalation of CO2)

16
Q

What is the reaction from lactate and NaHCO3 to H2O and CO2

A

lactate + NaHCO3 -> Na lactate + 2CO3 -> H2O + CO2

17
Q

What is ventilatory threshold

A

The point at which ventilation increases disproportionately with oxygen uptake during incremental exercise

18
Q

What are the 2 main factors that determine the energy requirement of breathing

A
  • Compliance of the lung and thorax

- Resistance of airways to smooth flow of air

19
Q

what is compliance

A

how easily these tissues stretch

20
Q

For a healthy individual at rest, what % of total oxygen consumption is to the respiratory muscles themselves

A

3-5%

21
Q

For a healthy individual at max, what % of total oxygen consumption is to the respiratory muscles themselves

A

10-15%

22
Q

As compliance of respiratory muscels decreases, work of breathing ____

A

Increases

23
Q

What is an example of a condition where the compliance or air resistance in the respiratory system is decreased

A

Chronic Obstructive Pulmonary Disease

24
Q

for people with COPD, what % of total oxygen consumption is to the respiratory muscles themselves at max

A

40%

25
Q

What is the O2, CO2 and N content in ambient air

A

O - 20.93%
CO2 - 0.03%
N - 79.04%

26
Q

If air is humidified what occurs to O2

A

decreases by 10 mmHg

27
Q

Why is PO2 lower in alveoli air than inspired air ? and what is it>

A

incoming air mixes with residual air which has already had some of the O2 removed from it 100 mm Hg

28
Q

What do the partial pressures of O2 and CO2 in alveoli and blood allow

A

O2 to travel down the gradient into blood. and to CO2 to leave the blood via the gradient

29
Q

What is the equation for partial pressure

A

% concentration x Total gas mixture pressure

30
Q

Inspired air has a PO2 of? CO2?

A

159 mm Hg

0.2 mm Hg

31
Q

What is the Po2 and PCO2 of skeletal muscle

A

46mm Hg

40 mm Hg

32
Q

How is oxygen carried in blood

A

dissolved in fluid portion of blood
or
Combined with hemoglobin with red blood cells

33
Q

How much O2 is dissolved in blood itself

A

only 1.5%

34
Q

How much O2 is in bound to hemoglobin

A

98.5%

35
Q

What is the oxygen carrying capacity of blood in men and women?

A

M - 20.1 mL per 100 mL blood

W - 18.8 mL per 100 mL blood

36
Q

What is the oxygen carrying capacity of hemoglobin

A

1.34

37
Q

Do men or women have more hemoglobin

A

men

38
Q

What is SaO2

A

% saturation - how saturated the hemoglobin is with oxygen

39
Q

How do you measure SaO2

A

Pulse oxymeter using infrared light

40
Q

what is SaO2 of hemoglobin in lungs at rest?

A

98%

41
Q

what is SaO2 of hemoglobin in tissue at rest?

A

75%

42
Q

What is the plateau of the oxyhemoglobin curve consistent with

A

PO2 at pulmonary capillaries

43
Q

What are the consequences of alveolar & arterial PO2 falling 40%

A
  • %Hb saturation remains at 90%
  • Total O2 content in the blood is only slightly decreased
    • even if youa re not airating properly you still have a high oxygen carrying capacity in blood is very high - Safety mechanism!!
44
Q

The plateau provides …

A

a significant margin of safety in O2 carrying capacity of blood

45
Q

The steep portion of the oxyhemoglobin curve occurs where in the body …

A

systemic capillaries

46
Q

What does the steep portion of the oxyhemoglobin curve allow for

A

HbO2 to disassociate and O2 to diffuse to tissue cells

47
Q

What occurs to PO2during exercise - why is this good?

A

PO2 at tissues goes even lower - allows more o2 to enter the tissue as needed. Steep curve allows the oxygen to be given to the tissues is a very efficient manor

48
Q

What is the route of O2 from hemoglobin to tissue

A

O2 must travel from hemoglobin and dissolve into blood and then to the tissues.

49
Q

What does Hb saturation drop to at tissues with exercise

A

30%

50
Q

What is myoglobin

A

similar to Hb but at level of mitochondria - iron protein compound found in skeletal and cardiac muscle

51
Q

What does myoglobin facilitate

A

mitochondrial oxygen transfer

52
Q

When does myoglobin bind and retain oxygen

A

at low pressures

53
Q

In what 3 ways does blood carry CO2? and what % in each method?

A
  • In physical solution in plasma 7-10%
  • Combined with hemoglobin within red blood cell 20%
  • As plasma bicarbonate 70%
54
Q

Does delivering more oxygen improve exercise capacity

A

No, in healthy respiratory system your arterial blood is almost always fully saturated. Hemoglobin cant take any more. This is maintained even at high exercise levels

55
Q

Are more red blood cells able to improve exercise capacity?

A

Yes
- Blood doping, body replaces loss blood and hemoglobin in about 6 weeks. then you put old blood back in and you are performing above average, hemoglobin slowly returns and readjusts to normal levels

56
Q

With blood doping you can increase hemoglobin levels by how much

A

8-20%
15 g/dL to 19 g/dL blood
Increasing oxygen carrying capacity from 20.1 to 25.5

57
Q

Why is blood doping dangerous?

A

a large increase in cellular concentration leads to an increase in blood viscosity. This in turn

  • decreases cardiac output
  • increases systolic blood pressure
  • causes strain on heart
58
Q

what is the impact of blood doping on functional capacity

A
  • Increase O2 available to working muscles
  • Improved max aerobic performanace (5-13%)
  • Reduced submaximal HR and blood lactate for a standard exercise test
59
Q

What is EPO and what is its purpose

A

Erythropoietin - inject after removing blood for blood doping to allow athletes to continue to train at high levels

60
Q

Does regular endurance exercise stimulate large increases in the functional capacity of the pulmonary system

A

no - minor ability to

61
Q

Submax training may improve the endurance of the ventilatory muscles by…

A

16%

62
Q

How does training increase the endurance of ventilatory muscles

A
  • Increased aerobic enzymes at the level of the ventilatory muscles
  • Reduced fatigue of ventilatory muscles
  • Lowers oxygen demand from ventilatory muscles and frees up oxygen use by non-ventilatory muscles
  • Slower breathing rate for a given submaximal exercise rate, training can extract more oxygen
63
Q

How does the O2 composition of exhaled air change between trained and non trained individuals

A

trained - 15%

untrained - 17%