Ventilatory system Flashcards Preview

Zach's Physiology Card > Ventilatory system > Flashcards

Flashcards in Ventilatory system Deck (89)
Loading flashcards...
1
Q

What is the carina?

A
  • bifurcation of primary bronchi

- produce cough reflex

2
Q

What are the three branches of the bronchi and what do they supply?

A
  • primary: supply lungs
  • Secondary: supply lobes
  • Tertiary: supply lobules
3
Q

What are the inspiratory muscles?

A
  • diaphragm
  • ext. intercostal muscles
  • sternomastoids
  • serratus anterior
  • scalene
4
Q

What are the expiratory muscle?

A
  • abdominal and internal costals produce forceful expiration.
  • generally passive at rest.
5
Q

What are the branchings of the bronchioles?

A
  • terminal and respiratory

- with smooth muscle but no cartilage

6
Q

At what point in the respiratory tract do we begin to gain control of the amount of air we can take in?

A

The area of where we start to gain control of how much air is being passed for respiration.

7
Q

Define total lung capacity.

A

-maximum volume of gas the lungs can hold

8
Q

What helps to form the total lung capacity?

A

-non overlapping compartments form lung volumes

9
Q

Tidal volume is what and what volume?

A

500mL

volume inspired and expired with breathing

10
Q

Inspiratory reserve volume?

A
  • 3000mL
  • amount of air that can be inspired in addition to tidal volume
  • requires forced inspiration to do so
11
Q

Expiratory reserve volume?

A
  • 1100mL

- amount of air expired at end of tidal volume by forced expiration

12
Q

Residual volume?

A

1200mL

-amount of air remaining in the pulmonary system after forced expiration

13
Q

Vital capacity?

A

4600mL

  • sum of all air inspired/expired
  • max inspiration to max expiration
14
Q

Total lung capacity

A

sum of all volumes.

- includes vital capacity + residual volume

15
Q

Inspiratory capacity?

A

sum of volume above resting capacity

-therefore is tidal volume + inspiratory reserve volume

16
Q

Functional residual capacity

A

-expiratory reserve volume + residual volume

the sum of volume below resting capacity

17
Q

Describe minute volume and the equation to describe it.

A
  • volume of gases moved in or out of lungs per minute

- V= breath per minute * tidal volume

18
Q

What is alveolar ventilation and the equation to describe it?

A
  • volume of gases that enter spaces participating in gas exchange per minute
  • (bpm)*(TV-DS)
19
Q

What is anatomic dead space?

A

-the space where air remains in the trachea, bronchi, bronchioles

20
Q

What is physiological dead space?

A

-anatomic dead space+ventilated alveoli with poor perfusion

21
Q

What is pleural pressure?

A

-fluid between parietal and visceral pleura

22
Q

What is alveolar pressure?

A

-pressure inside the alveoli

23
Q

The transpulmonary pressure?

A

-difference between the alveolar pressure and the pleural pressure

24
Q

Total tidal volume is 0.5L so what is the amount of respirated and perfused alveoli in normal individual with dead space of .15L?

A

-0.35L

25
Q

The amount of CO2 in the arterial blood will be equal to what?

A

arterial CO2 level equals the amount of CO2 in the lungs

26
Q

How can we verify that dead space is the eqaution that is used?

A
  • dead space air does not participate in exchange and has negligible CO2
  • blood gases equilibrate during gas exchange in capillaries, therefore blood CO2 equals the CO2 in region of the lungs
27
Q

What happens to the pressure in the alveoli during inspiration/ expiration?

A
  • inspiration: decrease of pressure

- expiration: increase of pressure

28
Q

What is the compliance of the lungs?

A

-the extent to which lungs will expand for each unit incrase in transpulmonary pressure

29
Q

Compliance is a measure of what?

A

-the expansibility of the lungs and the trachea

30
Q

What is a major component that allows the lungs to function normally in air, and not at all in water?

A

Saline helps to reduce the amount of surface tension that opposes the movement of the lungs

31
Q

What component is similar to saline in the lungs that reduce surface tension and improve the ventilatory efficiency?

A

-surfactant

32
Q

Surfactant contains what three components secreted by what cells?

A
  • dipalmitoylphosphatidylcholine
  • surfactact apoproteins
  • Ca ions
  • produced by type II alveolar cells.
33
Q

What is the equation for surface tension on the pressure?

A

pressure= 2* surface tension/ alveolar radius

34
Q

By how much does surfactant reduce the surface tension in the lungs?

A

-reduces by 4.5 times.

35
Q

What cells, muscles and cartilage are in the trachea?

A
  • pseudostratified ciliated columnar with goblet cells
  • cartilaginous rings
  • trachealis muscle
36
Q

What are the high pressure/ low flow areas?

A

thoracic aorta, bronchial arteries, trachea, bronchial tree, adventitia, CT

37
Q

What are the low pressure/ high flow areas of the lungs?

A

pulmonary artery and branches to the alveoli

38
Q

What is the pressure gradient in the pulmonary system?

A

7 mmHg

39
Q

True False:

There is 9% of total blood volume of the body in the lung, where 70mL is in the pulmonary calillaries

A

True

40
Q

What happens if the left side of teh heart were to undergo a failure?

A
  • will increase pulmonary circulation, and BP

- there will be little effect in the systemic, due to the vast amount of fluid in that system

41
Q

True, False:

2% of the blood in the systemic arteries is blood that bypasses the pulmonary capillaries, and therefore contains less oxygen per deciliter than blood in equilibrium with alveolar air.

A

True

42
Q

Where does the blood in the physiologic shunt come from?

A

-this blood is supplied from the lung parenchyma and the left side of the heart

43
Q

What component contributes to the fact that arteriole blood has less oxygen per liter than in the alveolar capillaries?

A

-the physiologic shunt

44
Q

When oxygen concentration is at 73mmHg or lower what happens to the vasculature in the lungs?

A
  • blood vessels constrict by unknown method

- the poorly ventilated alveoli increase the blood to higher functioning alveoli

45
Q

What are the different zones of blood flow to the lungs and what can affect this distribution?

A
  • zone 1: when standing there is no blood flow, and alveolar pressure is higher than capillary pressure (pathological)
  • Zone 2: intermittent flow only during systole
  • Zone 3: continuous blood flow
46
Q

In a normal individual what type of zone can the lungs be divided into while standing?

A
  • apices have zone 2, and lower 2/3 will be a zone 3.

- strenuous exercise can convert all lobes/sections into zone 3

47
Q

What happens when one lungs blood supply is obstructed and what feature contributes to allow this?

A
  • unobstructed lung increases blood flow 2x

- this is due to passive dilation based on high level of capacitance of the pulmonary vessels

48
Q

What hormones constrict the pulmonary arterioles?

A

-norepinephrine
-einephrine
angiotensin II
-prostaglandins

49
Q

What agents help dilate the pulmonary arterioles?

A
  • isoproterenol

- acetylcholine

50
Q

What agents cause venule constriction of the pulmonary system?

A
  • serotonin
  • histamine
  • E coli endotoxin
51
Q

The sympathetic vasoconstrictor nerve fibers outflow from the cervical sympathetic ganglia and have what effect on vasculature?

A

-this decreases the pulmonary blood flow by 30% and mobilizes the blood from the pulmonary reserve to restore blood flow

52
Q

What happens to allow for increased blood flow through the pulmonary system during exercise?

A
  • opening of previously closed capillaries
  • distension of the capillaries
  • -overall this prevents large increases of pressure in the alveolar capillaries
53
Q

What are the benefits for the heart of opening new alveolar capillaries and improving there distensibility?

A

-prevents increased afterload of the heart, and therefore preventing pulmonary edema.

54
Q

What is the normal left atrial pressure?

A

6 mmHg

55
Q

If the left atrial pressure is 40-50 mmHg, what is likely to occur?

A

left sided heart failure

56
Q

An increase of 8mmHg in the left atria, is enough to cause what effect?

A

-increase the pulmonary arterial pressure

57
Q

The pulmonary capillaries are leaky to protein molecules and contribute to what type of colloid osmotic pressure difference when compared to the peripheral tissue?

A

-the pulmonary interstitial tissue is 2 times higher than peripheral due to higher levels of colloid osmotic pressure

58
Q

When does pulmonary edema occur within a matter of minutes that the lymphatic vessel are unable to compensate for?

A
  • left sided heart failure or mitral valve disease

- damage to pulmonary blood capillary membranes

59
Q

What happens when capillary pressure remains chronically elevated for 2 or more weeks?

A
  • the compensatory mechanisms have time to adjust and prevent death.
  • acute mechanisms will not be able to compensate as well.
60
Q

What are the most common causes of pleural effusion?

A
  • block lymphatic drainage from the pleural cavity
  • cardiac failure
  • reduced plasma colloid osmotic pressure
  • infection/inflammation
61
Q

Pleural effusion is also know as?

A

lung collapse when pleural space pressure elevates above -4mmHg

62
Q

True or False:

Hypoxia increases pressure in the pulmonary artery which is possibly due to release of prostaglandin.

A

True

63
Q

If blood flow to a section of the lung, what are the following effects that will occur?

A
  • alveolar PCO2 is decreased

- this causes constriction of the bronchi to that section of the lung

64
Q

What are the main components of air?

A
  1. 09% N
  2. 95% Oxygen
  3. 93% Ar
  4. 03% Carbon Dioxide
65
Q

What are is the only gas that exists in equilibrium between the atmosphere and the alveoli?

A

carbon dioxide

66
Q

The total pressure exerted by the mixture of non-reactive gasses is equal to the sum of the partial pressures of individual gasses?

A

Dalton’s Law

67
Q

Pressure and Volume are inversely proportional when an ideal gas is kept at a constant amount and constant temperature.

A

Boyle’s Law

68
Q

What contributes to the drop of gas concentrations in the alveoli compared to the atmosphere?

A

the alveoli contain water vapor and offset the ‘equilibrium’ between atmosphere and alveolar gas concentration

69
Q

At constant temperature, the amount of a given gas dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.

A

Henry’s Law

70
Q

What is the ideal gas law?

A

P=nRT/V

P= pressure
n= moles
R= gas constant
T= temperature in Kelvin
V=volume
71
Q

Henry’s Law is really mostly concerned with the solubility coefficient, which contributes to the ability of the gas to diffuse when it is dissolved in a liquid.

A

Class presentation

72
Q

Why will carbon dioxide exert less partial pressure than oxygen?

A

-carbon dioxide has a higher solubility and will therefore have a lower exertion of partial pressure

73
Q

The functional residual capacity of the lungs on average is 2300mL, and only has how much air inspired and expired?

A

350mL of air is brought into the alveoli

74
Q

What controls the oxygen concentration in the alveoli and its partial pressure?

A
  • rate of absorption of oxygen into the blood

- rate of new oxygen that enters into the lungs

75
Q

Why will alveolar ventilation not increase above 149mmHg?

A

The highest amount of oxygen partial pressure is 149mmHg in the atmosphere. Therefore it is the maxmimum amount that could be absorbed

76
Q

What is the partial pressure of carbon dioxide concentration in the alveoli controlled by?

A
  • if excretion increases in tissues then PCO2 increases

- PCO2 decreases as ventilation rate increases

77
Q

How thick should a membrane have to be in order to infere with gas exchange rates?

A

2-3X the normal thickness based on factors like edema, or fibrosis

78
Q

What is the primary reason people with COPD has poor gas exchange?

A

Membrane thickness has increased 2-3X the normal thickness

79
Q

What is Va/Q ratio?

A

-alveolar ventilation/ blood flow

80
Q

What is the normal range for Va/Q?

A

Va/Q= 0.8= 4/5

81
Q

Where in the capillary system is gas exchange considered complete?

A
  • initial third of the capillary
82
Q

If there is a pulmonary obstruction what happens to the Va/Q ratio?

A

-becomes 0 as Va=0 and therefore the blood gas composition remains the same. No gradient being created to drive exchange of gases

83
Q

What happens to the Va/Q when there is a vascular obstruction like an embolism?

A
  • Va/Q= infinity as Q=0
  • this prevents gas exchange, as no blood can contact the gases
  • this is considered a physiological shunt
84
Q

With a vascular obstruction what happens to the alveolar partial pressures of CO2 and O2?

A
  • PCO2= 0.0

- PO2 =149

85
Q

During normal alveolar perfusion PCO2 and PO2 are able to reach what levels?

A
  • PCO2= 40mmHg

- PO2= 104mmHg

86
Q

What is the best way to describe shunted blood?

A

-a certain amount of venous blood in the pulmonary capillaries that does not get oxygenated, normally occurring when Va/Q is below normal (0.8)

87
Q

The thin descending loop of henle is highly permeable to which components?

A

water

88
Q

Aldosterone is important for sodium reabsorption and potassium secretion, what does it target to do so?

A

principal cells

89
Q

The macula densa is found in what part of the renal tubule?

A

distal convoluted tubule