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Flashcards in Cardiopulmonary III Deck (110):
1

What is the natural state of the lungs?

Compressed

2

What connects the Lungs to the Thoracic cavity?

Adhesive nature of the fluid between the Visceral and Parietal pleura

3

What formula describes pressure changes in the lungs?

P1V1 = P2V2

4

If Intra-alveolar volume increases, pressure...

Decreases

5

If Intra-alveolar volume decreases, pressure...

Increases

6

Normal breathing is...
Ventilator breathing is...

Negative pressure breathing
Positive pressure breathing

7

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

Negative

*pulling back at compressed lungs

8

When does intrapleural pressure become positive?

Force expiration

9

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

Airway resistance
Alveolar surface tension
Lung compliance

10

What are the 2 receptors that affect bronchial radius?

Muscarinic (parasympathetic)
Beta-2 (sympathetic)

11

What does alveolar tension counteract?

Collapsing Pressure

12

Collapsing pressure is inversely proportional to...
Aka...

Alveolar Radius

Laplace's Law

13

What cells make surfactant in the lungs?

Type 2 Alveolar

14

What is the major component of surfactant?

Dipalmitoylphosphatidylcholine (DPPC)

*62%, and other amphipathic phospholipids

15

What is the primary function of surfactant?

Decrease surface tension

16

Higher humidity climates require more or less surfactant?

More

17

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

Low
High

18

What is the collapse of alveoli called?

Atelectasis

19

The opposite of stiffness is...

Compliance

20

Compliance =

Volume/Pressure

21

What antibody does allergen bind in the lung?
What does binding induce?

IgE

Mast cells release Histamine and Leukotrienes

22

What do Histamine and Leukotrienes cause?
What timeframe?

Contraction smooth muscles in bronchi

Occurs within 1 hour allergen exposure (early phase)

23

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

Eosinophils

4-5 hrs Late phase

24

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

False

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

25

The 4 physiological/pathological characteristics of asthma?

Increased responsiveness of trachea/bronchi
Bronchoconstriction
Inflammation
Thick mucus

26

What are the 2 most common obstructive lung diseases?

COPD (chronic obstructive pulmonary disease)
Asthma

27

What are 2 types of COPD?

Emphysema
Chronic bronchitis

28

What defines an obstructive lung disease?

Difficulty fully exhaling
(air lingers in lungs after full expiration)

29

What defines a restrictive lung disease?

Cannot fill lungs

*often because of stiffness

30

What are some conditions causing restrictive lung disease?

Obesity
ALS
Muscular dystrophy

31

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

FEV
(Forced Expiratory Volume)

32

What is the normal FEV (1.0)?

75-85% vital capacity exhaled in 1.0 seconds

33

FEV (1.0) below 75% suggests?
above 85% suggests?

Obstructive (difficulty exhaling)

Restrictive (no air left because difficulty filling lungs)

34

100% FEV =

FVC - forced vital capacity

35

By how much does Hemoglobin increase carrying capacity of blood?

70x

36

How much Oxygen is dissolved in plasma?
How much bound to Hb?

1.5%
98.5%

37

Structure of Hemoglobin.

2 Alpha
2 Beta
4 Heme subunits

38

What is the saturation of Arterial blood?
What is the saturation of Venous blood?

98-100%
75%

39

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

Positive cooperativity

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

40

Name 5 blood factors that influence Hemoglobin saturation.

Temperature
pH
2,3 BPG
2,3 DPG
CO2

41

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

2,3 BPG

(also 2,3 DPG)

42

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

pH
Temperature
CO2

43

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

What is this known as?

Increase in CO2
decrease in pH (more acidic)

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

44

How does exercise create the Bohr Effect?

tissues produce more CO2
decreases pH
Unloads Oxygen at tissues

45

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

Shifts to the right

(gives up Oxygen more easily)

46

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

2,3 DPG

47

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

2,3 DPG

*facilitates Oxygen unloading at the tissues

48

Shifts to the right ____ affinity of hemoglobin for Oxygen.
Shifts to the left _____ affinity of hemoglobin for Oxygen.

Decrease
Increase

49

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

200x

50

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

Left (increases affinity for remainder oxygen)
flatlines

51

A decrease in arterial oxygen is...
A decrease in oxygen delivery to tissues is...

Hypoxemia
Hypoxia

52

Three things that cause hypoxia:

Decrease Cardiac Output
Decreased Oxygen binding capacity Hb
Decreased arterial Oxygen

53

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

Anemic hypoxia

54

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

Ischemic (or stagnant) hypoxia

55

Lack of Oxygen because cell can't use:

Histotoxic hypoxia

(poisons)

56

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

Hypoxemic hypoxia

57

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

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

58

How is CO2, in the form of HCO3-, carried through the blood?
Where does rxn take place?

in RBC's

RBC's

59

What enzyme converts CO2 + H2O > H2CO3?
(bicarbonate)

Carbonic Anhydrase

(in erythrocyte)

60

H2CO3 > H+ + HCO3-
What prevents this from lowering blood pH?

H+ is bound to hemoglobin

61

What does the Chloride shift do at the tissues?

Binds RBC and kicks HCO3- into plasma

(this maintains osmotic equilibrium)

62

What does the Chloride shift do at the lung?

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

63

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

Ventilation - Perfusion Ratio
(V/Q)

64

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

0.8

(4.2 L/min ventilation / 5.5 L/min blood flow)

65

What could drive the V/Q ratio to zero?

Shunt

(blockage of airflow in lungs)

66

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

100 mm Hg Oxygen
40 mm Hg Carbon dioxide

67

What could drive the V/Q ratio to infinity?

Dead Space

*no circulatory perfusion by blockage

68

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

Where are they in brainstem?

Medullary respiratory center
Apneustic center
Pneumotaxic center

1st in Medulla, latter 2 in Pons

69

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

Where is it?

DRG - Dorsal Respiratory Group

Medulla

70

What does the DRG (Dorsal Respiratory Group) innervate?
What does the VRG (Ventral Respiratory Group) innervate?

Inspiratory muscles
Expiratory muscles

*make up Medullary Respiratory Center

71

What 2 cranial nerves are the DRG inputs?

What info do they input?

X Vagus - peripheral chemoreceptors and mechanoreceptors

IX Glossopharyngeal - peripheral chemoreceptors

72

What makes is the output of the DRG?
What does it innervate?

Phrenic nerve
Diaphragm
External Intercostals

73

When is the VRG active?

Exercise

*when passive expiration isn't enough

74

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

2 seconds active (inspiration)
3 seconds inactive (expiration)

75

What type of inspiration does the Apneustic Center stimulate?

Ispiratory gasps (apneusis)

brief exhalations

76

How does the Apneustic Center affect the Medulla?

Prolongs action potential in Phrenic nerve and contraction of diaphragm

77

What neuronal center limits the size of the Tidal Volume?
Where is it located?

Pneumotaxic Center
Upper Pons

78

What neuronal center limits action potentials of the Phrenic nerve?

Pneumotaxic Center

79

Hyperventilation causes blood pH to...

Increase

80

Where are the Central and Peripheral Chemoreceptors located?

Central - bilateral ventrolateral Medulla

Peripheral - aortic arch/carotid arteries

81

What stimuli increase the breathing rate?

Decrease pH
Increase CO2

*Medulla

82

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

Central or Peripheral

83

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

Peripheral

84

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

What is its normal range?

CO2

40 mm Hg

*controlled to within +/-3 mmHg

85

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

Central chemoreceptors

86

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

Why?

pH CSF

CO2 crosses BBB much easier than H+
must breath faster

*H+ acts directly on Medullary receptors

87

How does CO2 increase H+ in the CSF?

CO2 + H2O > H+ and HCO3-

*via carbonic anhydrase

88

What type of receptors are sensitive to arterial Oxygen?

Peripheral

*CO2 has much greater effects on these receptors

89

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

60 mmHg or below

90

What type of chemoreceptors are most important in regulating CO2?

Central

91

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

Hypoxic Drive

92

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

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

93

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

Lung stretch receptors
Irritant receptors
Joint and muscle receptors

94

What is the Herring-Breuer reflex?

Lung stretch reflex

*prevents over-expansion

95

Where are irritant receptors located?
What nerve innervates?

Between epithelial cells lining airways

Vagus

*restricts and increases breathing rate

96

What 2 components lead to increased breathing before exercise?

Anticipation (Pavlovian)
Stretching

97

For this class, Acids are...
Bases are...

Proton donors
Proton acceptors

98

Henderson Hasselbach:

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

*at 20:1 pH = 7.4

99

What is the normal range of pH in ECF?

7.35-7.45

100

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

Buffers
Lungs
Kidneys

101

What are the 3 major buffers in the body?

Bicarbonate (and protonated carbonic acid)
Phosphate
Protein

102

What parts of a protein respond to Acidosis?
Alkalosis?

acidosis: Amine accepts proton
alkalosis: carboxyl releases proton

103

What effect does hypoventilation have on pH?

decreases pH

104

What effect does Hyperventilation have on pH?

increase pH

105

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

Secretes H+ (distal convoluted tubule)

Reabsorbs HCO3- (prox. convoluted tubule)

Synthesizes HCO3- (prox. convoluted tubule)

106

What is Respiratory Acidosis caused by?
What are its effects in the kidney?

Emphysema (anything can't breath)

Increases secretion of H+

107

What causes Respiratory Alkalosis?
Effects in kidney?

Altitude, anxiety

Decrease secretion H+

108

What causes Metabolic Acidosis?
Effect on HCO3-?

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

*Kidneys secrete H+

109

What causes Metabolic Alkalosis?
Effect on HCO3-?

Severe emesis
Increase HCO3-

110

What are 2 strategies of dilating airways for asthma?

Beta-2 agonists (mimic norepinepherine)
Muscarinic blocks

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