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Flashcards in Norm fxn- Physiology Deck (157)
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1
Q

Which is the primary muscle for inspiration?

A

Diaphragm

2
Q

What is the biggest accessory muscle to help the diaphragm in inspiration?

A

Ext intercostals

3
Q

Give me 3 other accessory muscles to aid in inspiration.

A

SCM
Anterior Serrati
Scalenes

4
Q

True or False: expiration is usually passive from the normal recoil of the lungs, chest wall, and abd structures.

A

True!!!!!!!!!!!!!!!!!!!

5
Q

What are the main expiratory accessory muscles to aid in expiration if passive recoil isnt enough? (2)

A

Abd muscles and internal intercostals

6
Q

What causes the normal negative pressure within the pleural space?

A

excess pleural fluid is suctioned into the lymphatic channels continuously.

7
Q

What is the normal transmural pleural pressure at rest?

A

-5cm of H2O

8
Q

During inspiration, what does the negative transmural pressure jump to?

A

-7.5cm of H2O

9
Q

The increase of negative pressure causes how much volume to be sucked into the lung during normal respiration?

A

0.5L of air

10
Q

When no air is flowing in/out of the lungs, what is the pressure of the alveoli equal to?

A

Atmospheric pressure (0cm of H2O)

11
Q

During inspiration, what does the P(alv) drop to?

A

-1cm of H2O

12
Q

The drop in P(alv) during inspiration causes what to happen?

A

Air flows into the lungs

13
Q

This is the extent to which the lungs will expand for each unit increase in transpulmonary pressure.

A

Compliance

14
Q

Compliance of the lungs is determined by what 2 properties of eslastance?

A
  1. elastic forces of the lung tissue itself

2. eslastic forced caused by the surface tension of the fluid inside the walls of the alveoli

15
Q

How much of the total elastic forces are contibuted by only the tissues itself?

A

1/3

16
Q

So the other 2/3 of elastic forces are due to what other elastic factor?

A

surface tension

17
Q

In emphysema, there is a destruction of the elastic tissue, causing a change in elasticity and compliance how?

A

↓ elasticity

↑ compliance

18
Q

Is there an ↑ or ↓ in compliance in fibrotic lung disease?

A

19
Q

Upon full inspiration (to VC), will mostly elastance or compliance effects from the lungs be in place?

A

Elastance

20
Q

What happens to the transpulmonary pressure when you have a pneumothorax?

A

it equals atmospheric, so no neg pressure will be made, and thus no air will flow in.

21
Q

This is the volume of inspired or expired air ina normal breath (~0.5L).

A

Tidal volume (TV)

22
Q

This is the extra volume that can be inspired over the TV (~3L).

A

Inspiratory reserve volume (IRV)

23
Q

This is the max extra volume that can be expired after the end of a normal TV (~1L).

A

ERV

24
Q

This is the volume of air remaining in the lungs after the most forceful expiration (~1.2L).

A

Residual volume (RV)

25
Q

This is the volume of IRV + TV + ERV.

A

Vital capacity (VC)

the “blowing out the birthday candles” volume

26
Q

This is the volume of ERV + RV.

A

Functional residual capacity (FRC)

27
Q

This is the volume of VC + RV

A

Total lung capacity (TLC)

28
Q

What substance is the main contributor to surface tension?

A

Water

29
Q

And again, does surface tension ↑ compliance or elastance?

A

Elastance (2/3 of all elastic forces for the lungs)

30
Q

What is the eqn to see the collapsing prssure of the alveoli?

A

(Pressure to keep alveoli open) = (2 x surface tension)/(radius of alveolus)

Lapace law

31
Q

According to Lapace law, air will flow into a larger or smaller alveoli?

A

Larger, because an ↑ in radius ↓ the pressure required to keep the alveolus open

(P = 2T/r)

32
Q

This is the collapse or closure of the lung from reduced or absent gas exchange.

A

Atelectasis

33
Q

What are the 4 main components of surfactant?

A

phospholipids, DPPC, surface apoproteins, and Ca++ ions

34
Q

Which cells make surfactant?

A

Type II alveolar cells

35
Q

What is the role of surfactant for the lungs?

A

Reduce surface tension –> reduce pressure to keep the alveolus open

(P = 2T/r)

36
Q

True or false: the alveoli at the apex of the lung are larger than the alveoli at the base of the lung due to gravity.

A

True

37
Q

Since the alveoli at the apex of the lung are larger, is their compliance lower or higher?

A

Lower

38
Q

What is the eqn for minute respiratory volume?

A

MRV = TV x (respiratory rate)

39
Q

This is the total exchange of air in the lungs.

A

Pulmonary ventilation

40
Q

This is the amount of new air that reaches the alveoli in 1 min.

A

Alveolar ventilation

41
Q

This si the volume of air in the conducting pathways that does not partiipate in gas exchange.

A

Anatomic dead space

42
Q

This is not really a volume, but when alvoli are nonfxnl or partially fxnl.

A

Alveolar dead space

43
Q

this is the total dead space and made from anatomic + alveolar dead space.

A

Physiological dead space (VD)

44
Q

What is the alveolar ventilation eqn?

A

Va = rate x (VT - VD)

always make sure to substract dead space when calculating alv vent. they will have answers on the exam where the #’s match if you didn’t subtract it out.

45
Q

The SANS causes what to the bronchioles, dilation or constriction?

A

Dilation

46
Q

Histamine is a big factor in anaphylactic conditions, which causes what to the bronchioles, dilaiton or constriction?

A
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47
Q

This is when VENTILATION is inadequate to perform needed gas exchange.

A

Hypoventilation

48
Q

This is when u breathe too much because your heart is racing from seeing your boyfriend of 8 months return from a long business trip in taiwan and you’re ignoring the fact that he night have gotten the clap form that questionable toilet seat.

A

Hyperventilation

49
Q

This is when there’s too much CO2 in the blood

A

Hypercapnea

50
Q

This is normal breathing

A

Eupnea

51
Q

This is shallow breathing or an abnormally low respiratory rate.

A

Hypopnea

52
Q

This is an increased depth of breathing in order to meet metabolic needs.

A

Hyperpnea

53
Q

Are brochial aa. that supply the lung system with delicious nutricious arterial blood high pressure or low pressure?

A

High

54
Q

Is blood from the pulmonary a. high pressure or low?

A

Low

55
Q

What is the BP of the RV?

A

25/8

56
Q

What is the MAP of the pulmonary a.?

A

15mmHg

57
Q

What is the MAP of the pulmonary capillaries?

A

7mmHg

58
Q

What is the MAP of the LA?

A

2mmHg

59
Q

When PO2 drops below 73mmHg, do small arteries constrict or dilate?

A

Constrict

60
Q

Why do small arteries constrict under hypoxia?

A

Diverts blood to the areas where it’s most effective

61
Q

Why is there no blood flow in Zone 1?

A

P(alv) is greater than arterial pressure

62
Q

What changes can cause intermittent blood flow in Zone 2?

A

When systolic arterial pressure overcomes P(alv)

63
Q

True or False: arterial flow is continuous in a Zone 3 of the lung.

A

True

64
Q

The apices of the lungs typically have which zone (1, 2, or 3)?

A

zone 2

65
Q

The base of the lungs typically have which zone (1, 2, or 3)?

A

zone 3

66
Q

So when do you get a zone 1?

A

severe blood loss or breathing against a + air pressure

67
Q

During exercise, does increasing the # of open capillaries, distending the capillaries, and increasing pulmonary arterial pressure increase or decrease blood flow?

A

Increase about 4-5x normal

68
Q

At what pressure do u see pulm edema from LHF?

A

> 30mmHg

69
Q

During lung inflation, what happens meechanically to alveolar vessels to increase pulm resistance?

A

Mechanically compressed

70
Q

What is the colloid pressure of the pulmonary interstitial fluid?

A

14mmHg

71
Q

What is the equation to relate partial pressure with solubility?

A

P = (conc of gas)/(solubility coefficient)

72
Q

How do you calculate PO2 in atomospheric air?

A

PO2 = (760mmHg - 47mmHg)*0.21 = 150mmHg

the 47 comes from water

73
Q

What are the 4 factors that affect the rate of gas diffusion across the respiratory membrane?

A
  1. thickness
  2. surface area
  3. diffusion coefficient
  4. partial pressure difference of the gas
74
Q

Ventilation and perfusion are highest where, at the apices or bases of the lung?

A

Base

75
Q

Where is the V/Q ratio the highest, at the apices or bases of the lung?

A

Apices

lots of ventilation but poor perfusion

76
Q

Where is PCO2 hihger, at the apices or bases of the lung?

A

Base

77
Q

Where is PO2 higher, at the apices or bases of the lung?

A

Apices

cuz there is more gas exchange

78
Q

What is the V/Q at the portion of the lung if there is a blockage?

A

0

79
Q

Will a PE ↑ or ↓ V/Q?

A

↑ a lot

80
Q

In high altitude, what will happen with the PaO2 and A-a gradient?

A

PaO2 ↓

A-a normal

81
Q

In hypoventilation, what will happen with the PaO2 and A-a gradient?

A

PaO2 ↓

A-a normal

82
Q

In fibrosis (diffusion defect), what will happen with the PaO2 and A-a gradient?

A

PaO2 ↓

A-a ↑

83
Q

In a V/Q defect, what will happen with the PaO2 and A-a gradient?

A

PaO2 ↓

A-a ↑

84
Q

In a R-L shunt, what will happen with the PaO2 and A-a gradient?

A

PaO2 ↓

A-a ↑

85
Q

How do you calculate PAO2?

A

PAO2 = (PIO2 - PACO2)/R

where R= respiratory exchange ratio or respiratory quotient

86
Q

What is the PO2 and PCO2 of inspired air?

A

PO2- 160mmHg

PCO2- 0.3

87
Q

What is the PO2 and PCO2 in the alveoli?

A

PO2- 104

PCO2- 40

88
Q

What is the PO2 and PCO2 of the pulmonary a.?

A

PO2- 104

PCO2- 40

89
Q

What is the PO2 and PCO2 of arteries?

A

PO2- 95

PCO2- 40

90
Q

What is the PO2 and PCO2 of veins?

A

PO2- 40

PCO2- 46

91
Q

The amount of time blood is in the pulmonary artery decreases when there is an increase in what factor during exercise?

A

Cardiac output

92
Q

The ↓ in the time the blood is in the capillary does what to the amount of O2 that diffuses?

A

93
Q

However, there is a safety mechanism to counter the ↓ of time of blood in the capillary during exercise, because normal blood gets fully oxygenated by passing through what length of the capillary?

A

Fully oxygenated during the first 1/3 of the capillary

94
Q

So during exercise, the ↑ CO doesnt matter cuz blood can still get oxygen during what remaining span of the capillary?

A

The remaining 2/3, so we’re sitll fully oxygenated.

95
Q

Does ↑ tissue blood flow ↑ or ↓ PO2?

A

↑ PO2

96
Q

Does ↑ tissue metabolism ↑ or ↓ PO2?

A

↓ PO2

97
Q

True or False: the rate of diffusion of CO2 and O2 are essenitally the same across capillaries.

A

FALSE. CO2 can diffuse about 20x as rapidly as O2

98
Q

Does ↑ blood flow ↑ or ↓ PCO2?

A

↓ PCO2

takes away more CO2 faster

99
Q

Does ↑ tissue metabolism ↑ or ↓ PCO2?

A

↑ PCO2

making more CO2 ↑ PCO2 omgomgomgg

100
Q

What % of O2 is bound to Hb?

A

98.5% according to Little

book says 97%

101
Q

What is the VOLUME of O2 in the blood (per 100mL) when Hb is fully saturated?

A

20mL

102
Q

What is the volume of O2 that is transported from the lungs to the tissues if we subtract the amt in the arteries from the amt in veins?

A

~5mL

103
Q

This is the principle when increases in blood CO2 and H+ levels enhance the release of O2 from the blood in the tissues and enhances oxygenation of the blood in the lungs.

A

Bohr effect

104
Q

An increase in what 4 things shift the O2-Hb dissociation curve to the R?

A

H+
DPG
CO2
Temp

105
Q

What PCO is needed to be lethal from irreversible binding to Hb?

A

0.6mmHg

106
Q

What % of CO2 is dissolved?

A

7%

107
Q

What is the volume of dissolved CO2 transported around the body to the lungs? (use the difference between arterial and venous)

A

0.3mL

108
Q

What % of CO2 gets converted to HCO3-?

A

70%

109
Q

What enzyme converts CO2 and H2O into H2CO3?

A

Carbonic anhydrase

110
Q

Once H2CO3 splits into H+ and HCO3 inside the RBC, what binds the H+?

A

Hb to form HHb

111
Q

What exchanges for HCO3- on the membrane to put HCO3 into the plasma?

A

Cl-

112
Q

So is venous blood [Cl-] higher or lower than arterial [Cl-]?

A

Lower

113
Q

What % of CO2 directly binds to Hb to form carabinohemoglobin (CO2Hb)?

A

23%

114
Q

This is the principle when the binding of O2 displaces CO2 from the blood.

A

Haldane effect

115
Q

Co2 is displaced from the Hb on the fact that the O2-Hb complex forms what, a stronger acid or stronger base?

A

Acid

116
Q

What is the eqn for the respiratory exhcange ratio?

A

R = (rate of CO2 output)/(rate of O2 uptake)

117
Q

What is the R when a person is eating exclusively carbs?

A

R = 1.00

118
Q

What is the R when a person is eating exclusively fats?

A

R = 0.7

119
Q

What is the R when a person is eating a balanced diet?

A

R = 0.825

120
Q

What is the main function of the dorsal respiratory group of the medulla?

A

Causes inspiration

121
Q

What is the main function of the ventral respiratory group of the medulla?

A

expiration

122
Q

What is the main function of the pneuotaxic center of the superior pons?

A

Controls rate and depth of breathing

123
Q

Where are the neurons in the medulla for the dorsal respiratory group?

A

Nucleus of the Tractus Solitarius (NTS)

124
Q

Which 2 nerves give sensory innervation the NTS?

A

IX and X

125
Q

The dorsal respiratory group emits what to contril the basic rhythm of breathing?

A

repetitive bursts of inspiratory neuronal action potentials

126
Q

this is the form of information from the dorsal respiratory group to the diaphragm that begins weakly, increases steadily and then ceases.

A

Ramp signal

127
Q

What 2 ways does the pneumotaxic center from the upper pons control the ramp signal to regulate breathing?

A
  1. Limits the duration (early ceasing)

2. Increasing the rate of breathing

128
Q

This is the center in the lower pons where there are deep and prolonged inspiratory gasps.

A

Apneustic center

129
Q

True or False: during normal, quiet breathing, the ventral respiratory group neurons are inactive.

A

True!

130
Q

So activation of the ventral respiratory gorup dring increased ventilation causes what?

A

Heavy expiration by activating abd muscles

131
Q

True or False: H+ ions directly sitmulate the central chemoreceptors by crossing the BBB.

A

False. They can’t cross the BBB. They need to be in the form of CO2 to cross the BBB

132
Q

Which changes mainly stimulate the peripheral chemoreceptors, changes in O2 or CO2?

A

O2

133
Q

Where are the peripheral chemoreceptors in the body?

A

carotid and aortic bodies

134
Q

Which nerves from the carotid bodies take the information to IX?

A

Herings nerves

135
Q

IX (from the carotid bodies) and X (from the aortic arch) take information to where in the brain?

A

Dorsal Respiratory Group

136
Q

At what PO2 are the peripheral chemoreceptors stimulated?

A

<60mmHg

137
Q

Why is <60mmHg significant to stimulate the peripheral cehmoreceptors?

A

Cuz at a PO2 of 60mmHg, 90% of Hb is saturated (from looking at the dissociation curve)

138
Q

True or False: although peripheral chemoreceptors don’t respond well to PCO2 or pH, they respond more rapidly than the central chemoreceptors.

A

True

139
Q

Which has a stronger regulatory effect of ventilation, PCO2 or pH?

A

PCO2

140
Q

What are the changes in the central chemoreceptors to acclimatize for high altitudes?

A

It loses its sensitivity to changes in PCO2 and H+ ions

141
Q

What causes an immediate increase in ventilation (anatomically) during exercise?

A

the brain simulation the exercising muscles send simultaneous signals to the respiratory center to ↑ respiration

142
Q

These are receptors on the musucular portions of the walls of the bronchi and bronchioles and signals the DRG to prevent overstretching.

A

Stretch receptors

143
Q

THis is the reflex where stretch receptor activation stops the inspiration.

A

Hering-Bruer Inflation Reflex

144
Q

Which receptors are initiated to causes coughing and sneezing?

A

Irritant receptors

145
Q

Irritant receptors may also be responsible for bronchial constriction or dilation?

A

Constriction

146
Q

These are the receptors in the alveolar walls next to pulmonary capillaries and are stimualted when pulmonary capillaries ahve become engorges with blood or fluid.

A

J (juxtacapillary) receptors

147
Q

J receptor activation causes what Sx?

A

Dyspnea (difficult, rapid, shallow breathing).

148
Q

What is the FEV1 for a normal lung?

A

80%

149
Q

Which disease causes a decreased FEV1, obstructive or restrictive pulmonary disease?

A

Obstructive

150
Q

Is FEV1 increased or decreased or normal in restrictive lung diseases?

A

Increased

151
Q

What happens to TLC, RV, and max expiratory flow in obstructive lung disease?

A

TLC ↑
RV ↑
Max expiratory flow ↓

152
Q

What happens to TLC, RV, and max expiratory flow in restrictive lung disease?

A

TLC ↓
RV ↓
Max expiratory flow ↓

153
Q

What type of therapy is 100% effective if there is atmospheric hypoxia?

A

O2

154
Q

Will O2 therapy help with hypoventilation hypoxia?

A

yes a good amt.

155
Q

However, in hypoventilation hypoxia, O2 therapy doesnt get rid of what?

A

CO2

156
Q

Is O2 therapy veneficial in anemia, abnormal Hb, circulatory deficicency, or physiological shunts?

A

A tiny bit

157
Q

Is O2 therapy beneficial in hypoxia from inadequate tissue use of O2?

A

NO