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Flashcards in Cardiopulmonary III Deck (110)
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1
Q

What is the natural state of the lungs?

A

Compressed

2
Q

What connects the Lungs to the Thoracic cavity?

A

Adhesive nature of the fluid between the Visceral and Parietal pleura

3
Q

What formula describes pressure changes in the lungs?

A

P1V1 = P2V2

4
Q

If Intra-alveolar volume increases, pressure…

A

Decreases

5
Q

If Intra-alveolar volume decreases, pressure…

A

Increases

6
Q

Normal breathing is…

Ventilator breathing is…

A

Negative pressure breathing

Positive pressure breathing

7
Q

At the point between exhale and inhale, the intrapleural pressure is…

A

Negative

*pulling back at compressed lungs

8
Q

When does intrapleural pressure become positive?

A

Force expiration

9
Q

What are the 3 factors that hinder air passage in breathing?

A

Airway resistance
Alveolar surface tension
Lung compliance

10
Q

What are the 2 receptors that affect bronchial radius?

A

Muscarinic (parasympathetic)

Beta-2 (sympathetic)

11
Q

What does alveolar tension counteract?

A

Collapsing Pressure

12
Q

Collapsing pressure is inversely proportional to…

Aka…

A

Alveolar Radius

Laplace’s Law

13
Q

What cells make surfactant in the lungs?

A

Type 2 Alveolar

14
Q

What is the major component of surfactant?

A

Dipalmitoylphosphatidylcholine (DPPC)

*62%, and other amphipathic phospholipids

15
Q

What is the primary function of surfactant?

A

Decrease surface tension

16
Q

Higher humidity climates require more or less surfactant?

A

More

17
Q

Large alveoli have _____ collapsing pressures while small alveoli have _____ collapsing pressures.

A

Low

High

18
Q

What is the collapse of alveoli called?

A

Atelectasis

19
Q

The opposite of stiffness is…

A

Compliance

20
Q

Compliance =

A

Volume/Pressure

21
Q

What antibody does allergen bind in the lung?

What does binding induce?

A

IgE

Mast cells release Histamine and Leukotrienes

22
Q

What do Histamine and Leukotrienes cause?

What timeframe?

A

Contraction smooth muscles in bronchi

Occurs within 1 hour allergen exposure (early phase)

23
Q

What type of inflammatory cells are preferentially drawn into the lungs in response to an allergic reaction?
What timeframe?

A

Eosinophils

4-5 hrs Late phase

24
Q

T/F

There is no genetic component to making IgE antibody associated with asthma.

A

False

probably genetic
*can be allergic or non-specific like cold or exercise

25
Q

The 4 physiological/pathological characteristics of asthma?

A

Increased responsiveness of trachea/bronchi
Bronchoconstriction
Inflammation
Thick mucus

26
Q

What are the 2 most common obstructive lung diseases?

A

COPD (chronic obstructive pulmonary disease)

Asthma

27
Q

What are 2 types of COPD?

A

Emphysema

Chronic bronchitis

28
Q

What defines an obstructive lung disease?

A

Difficulty fully exhaling

air lingers in lungs after full expiration

29
Q

What defines a restrictive lung disease?

A

Cannot fill lungs

*often because of stiffness

30
Q

What are some conditions causing restrictive lung disease?

A

Obesity
ALS
Muscular dystrophy

31
Q

What is another way of assessing pulmonary function besides measuring respiratory volumes and capacities using spirometry?

A

FEV

Forced Expiratory Volume

32
Q

What is the normal FEV (1.0)?

A

75-85% vital capacity exhaled in 1.0 seconds

33
Q

FEV (1.0) below 75% suggests?

above 85% suggests?

A

Obstructive (difficulty exhaling)

Restrictive (no air left because difficulty filling lungs)

34
Q

100% FEV =

A

FVC - forced vital capacity

35
Q

By how much does Hemoglobin increase carrying capacity of blood?

A

70x

36
Q

How much Oxygen is dissolved in plasma?

How much bound to Hb?

A
  1. 5%

98. 5%

37
Q

Structure of Hemoglobin.

A

2 Alpha
2 Beta
4 Heme subunits

38
Q

What is the saturation of Arterial blood?

What is the saturation of Venous blood?

A

98-100%

75%

39
Q

What accounts for the sigmoid shape of the Oxygen-Hemoglobin binding curve?
How does this manifest physiologically?

A

Positive cooperativity

Easier to pick up Oxygen at lungs and drop off at tissues

40
Q

Name 5 blood factors that influence Hemoglobin saturation.

A
Temperature
pH
2,3 BPG
2,3 DPG
CO2
41
Q

What RBC binding factor affecting Hemoglobin saturation with Oxygen is made by RBC’s as the break down glucose?

A

2,3 BPG

also 2,3 DPG

42
Q

What are the 3 most important factor that influence Hemoglobin saturation?

A

pH
Temperature
CO2

43
Q

What shifts the Hemoglobin binding curve to the RIGHT?
(decreases affinity for Oxygen)

What is this known as?

A

Increase in CO2
decrease in pH (more acidic)

Bohr Effect
(shifts to the right increase unloading Oxygen in tissues)

44
Q

How does exercise create the Bohr Effect?

A

tissues produce more CO2
decreases pH
Unloads Oxygen at tissues

45
Q

What does an increase of temperature do to the Hemoglobin binding curve?

A

Shifts to the right

gives up Oxygen more easily

46
Q

What binds to the Beta chains of deoxyhemoglobin and decreases the affinity of hemoglobin for Oxygen?

A

2,3 DPG

47
Q

What blood factor is increased in those that live at high altitude?

A

2,3 DPG

*facilitates Oxygen unloading at the tissues

48
Q

Shifts to the right ____ affinity of hemoglobin for Oxygen.

Shifts to the left _____ affinity of hemoglobin for Oxygen.

A

Decrease

Increase

49
Q

What is the affinity Hemoglobin has for Carbon Monoxide compared to Oxygen?

A

200x

50
Q

Carbon monoxide binding shifts the curve to the _____, then _____.

A

Left (increases affinity for remainder oxygen)

flatlines

51
Q

A decrease in arterial oxygen is…

A decrease in oxygen delivery to tissues is…

A

Hypoxemia

Hypoxia

52
Q

Three things that cause hypoxia:

A

Decrease Cardiac Output
Decreased Oxygen binding capacity Hb
Decreased arterial Oxygen

53
Q

What is lack of Hemoglobin (due to RBC or Hb deficiency) called?

A

Anemic hypoxia

54
Q

What is blockage of blood flow leading to bad delivery of oxygen called?

A

Ischemic (or stagnant) hypoxia

55
Q

Lack of Oxygen because cell can’t use:

A

Histotoxic hypoxia

poisons

56
Q

Lack of Oxygen due to… lack of oxygen (pulmonary disease, altitude, etc).

A

Hypoxemic hypoxia

57
Q

What are the 3 ways Carbon Dioxide is carried in the blood?

A

Dissolved (small amount)
Carbaninohemoglobin (also small amount)
HCO3- (major form)

58
Q

How is CO2, in the form of HCO3-, carried through the blood?

Where does rxn take place?

A

in RBC’s

RBC’s

59
Q

What enzyme converts CO2 + H2O > H2CO3?

bicarbonate

A

Carbonic Anhydrase

in erythrocyte

60
Q

H2CO3 > H+ + HCO3-

What prevents this from lowering blood pH?

A

H+ is bound to hemoglobin

61
Q

What does the Chloride shift do at the tissues?

A

Binds RBC and kicks HCO3- into plasma

this maintains osmotic equilibrium

62
Q

What does the Chloride shift do at the lung?

A

Chloride leaves RBC for HCO3- and is converted back to CO2.

63
Q

What matches to achieve the ideal exchange of Oxygen and Carbon dioxide?

A

Ventilation - Perfusion Ratio

V/Q

64
Q

What is the V/Q ratio if the frequency, tidal volume, and cardiac output are normal?

A
  1. 8

4. 2 L/min ventilation / 5.5 L/min blood flow

65
Q

What could drive the V/Q ratio to zero?

A

Shunt

blockage of airflow in lungs

66
Q

What are the normal pressures of Oxygen and Carbon Dioxide in the blood?

A

100 mm Hg Oxygen

40 mm Hg Carbon dioxide

67
Q

What could drive the V/Q ratio to infinity?

A

Dead Space

*no circulatory perfusion by blockage

68
Q

What are the 3 groups of neurons in the brainstem that control breathing?

Where are they in brainstem?

A

Medullary respiratory center
Apneustic center
Pneumotaxic center

1st in Medulla, latter 2 in Pons

69
Q

What group of nerves is responsible for spontaneous breathing and is perhaps the most important set of nerves we have?

Where is it?

A

DRG - Dorsal Respiratory Group

Medulla

70
Q

What does the DRG (Dorsal Respiratory Group) innervate?

What does the VRG (Ventral Respiratory Group) innervate?

A

Inspiratory muscles
Expiratory muscles

*make up Medullary Respiratory Center

71
Q

What 2 cranial nerves are the DRG inputs?

What info do they input?

A

X Vagus - peripheral chemoreceptors and mechanoreceptors

IX Glossopharyngeal - peripheral chemoreceptors

72
Q

What makes is the output of the DRG?

What does it innervate?

A

Phrenic nerve
Diaphragm
External Intercostals

73
Q

When is the VRG active?

A

Exercise

*when passive expiration isn’t enough

74
Q

How much time does the DRG spend in the Active and Inactive states in normal breathing?

A

2 seconds active (inspiration)

3 seconds inactive (expiration)

75
Q

What type of inspiration does the Apneustic Center stimulate?

A

Ispiratory gasps (apneusis)

brief exhalations

76
Q

How does the Apneustic Center affect the Medulla?

A

Prolongs action potential in Phrenic nerve and contraction of diaphragm

77
Q

What neuronal center limits the size of the Tidal Volume?

Where is it located?

A

Pneumotaxic Center

Upper Pons

78
Q

What neuronal center limits action potentials of the Phrenic nerve?

A

Pneumotaxic Center

79
Q

Hyperventilation causes blood pH to…

A

Increase

80
Q

Where are the Central and Peripheral Chemoreceptors located?

A

Central - bilateral ventrolateral Medulla

Peripheral - aortic arch/carotid arteries

81
Q

What stimuli increase the breathing rate?

A

Decrease pH
Increase CO2

*Medulla

82
Q

A decrease in pH and/or increase in CO2 will stimulate what type of chemoreceptor?

A

Central or Peripheral

83
Q

An decrease of Oxygen below 60 mm Hb will stimulate what kind of chemoreceptor?

A

Peripheral

84
Q

What is the most potent and closely controlled chemical influencing respiration?

What is its normal range?

A

CO2

40 mm Hg

*controlled to within +/-3 mmHg

85
Q

What is the main mechanism of control over the effects of CO2?

A

Central chemoreceptors

86
Q

What is the central Chemoreceptor in the Medulla particularly sensitive to?

Why?

A

pH CSF

CO2 crosses BBB much easier than H+
must breath faster

*H+ acts directly on Medullary receptors

87
Q

How does CO2 increase H+ in the CSF?

A

CO2 + H2O > H+ and HCO3-

*via carbonic anhydrase

88
Q

What type of receptors are sensitive to arterial Oxygen?

A

Peripheral

*CO2 has much greater effects on these receptors

89
Q

At what point does dearth of Oxygen become a major stimulus to peripheral chemoreceptors?

A

60 mmHg or below

90
Q

What type of chemoreceptors are most important in regulating CO2?

A

Central

91
Q

What is the term for the result chemoreceptor adaptation in which Oxygen takes over as the primary chemical regulator?
(often due to pulmonary disease)

A

Hypoxic Drive

92
Q

Why is gas mixture only slightly enriched with Oxygen in people with Hypoxic Drive?

A

If it’s too high (above 60 mmHg) will slow breathing.

93
Q

Name 3 non-chemical receptors that also input to the brainstem and regulate breathing?

A

Lung stretch receptors
Irritant receptors
Joint and muscle receptors

94
Q

What is the Herring-Breuer reflex?

A

Lung stretch reflex

*prevents over-expansion

95
Q

Where are irritant receptors located?

What nerve innervates?

A

Between epithelial cells lining airways

Vagus

*restricts and increases breathing rate

96
Q

What 2 components lead to increased breathing before exercise?

A

Anticipation (Pavlovian)

Stretching

97
Q

For this class, Acids are…

Bases are…

A

Proton donors

Proton acceptors

98
Q

Henderson Hasselbach:

A

pH = pKa + log [HCO3-] / [CO2]

*at 20:1 pH = 7.4

99
Q

What is the normal range of pH in ECF?

A

7.35-7.45

100
Q

What are the 3 lines of defense against increase in H+?

A

Buffers
Lungs
Kidneys

101
Q

What are the 3 major buffers in the body?

A

Bicarbonate (and protonated carbonic acid)
Phosphate
Protein

102
Q

What parts of a protein respond to Acidosis?

Alkalosis?

A

acidosis: Amine accepts proton
alkalosis: carboxyl releases proton

103
Q

What effect does hypoventilation have on pH?

A

decreases pH

104
Q

What effect does Hyperventilation have on pH?

A

increase pH

105
Q

What are the 3 ways kidneys regulate pH and where does this regulation occur?

A

Secretes H+ (distal convoluted tubule)

Reabsorbs HCO3- (prox. convoluted tubule)

Synthesizes HCO3- (prox. convoluted tubule)

106
Q

What is Respiratory Acidosis caused by?

What are its effects in the kidney?

A

Emphysema (anything can’t breath)

Increases secretion of H+

107
Q

What causes Respiratory Alkalosis?

Effects in kidney?

A

Altitude, anxiety

Decrease secretion H+

108
Q

What causes Metabolic Acidosis?

Effect on HCO3-?

A

Production of H+ (ketoacidosis, etc)
Decreases HCO3-

*Kidneys secrete H+

109
Q

What causes Metabolic Alkalosis?

Effect on HCO3-?

A

Severe emesis

Increase HCO3-

110
Q

What are 2 strategies of dilating airways for asthma?

A

Beta-2 agonists (mimic norepinepherine)

Muscarinic blocks

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