Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y1 Respiratory > Physiology > Flashcards

Physiology Flashcards

1
Q

what is internal respiration?

A

the intracellular mechanisms that consume oxygen and produce CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is external respiration?

A

the sequence of events that leads to the exchange of oxygen and CO2 between the external environment and the cells of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the four steps of external respiration?

A

ventilation
gas exchange (alveoli to blood)
gas transport in blood
gas exchange (blood to tissue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is ventilation?

A

the mechanical process of moving air in and out of the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what body systems are involved in external respiration?

A

respiratory
cardiovascular
haematological
nervous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when can air flow into the lungs?

A

when intra-alveolar pressure is less than atmospheric pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does contraction of the inspiratory muscles cause?

A

expansion of the thorax and the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does boyle’s law state?

A

at any constant temperature, the pressure exerted by a gas varies inversely with the volume of the gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the two forces that hold the thoracic wall and the lungs in close opposition?

A

intrapleural fluid cohesiveness

negative intrapleural pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does intrapleural fluid cohesiveness work?

A

water molecules in intrapleural fluid are attracted to each other and resist being pulled apart, causing the pleural membranes to stick together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does negative intrapleural pressure work?

A

sub-atmospheric intrapleural pressure creates a transmural pressure gradient across the wall of the lung and the chest, forcing the lungs to expand when the chest squeezes inwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

is inspiration an active or passive process?

A

active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does inspiration depend on?

A

muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what effect does contraction of the diaphragm have on the volume of the thorax?

A

increases it vertically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

which nerve innervates the diaphragm?

A

the phrenic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does contraction of the external intercostal muscles cause?

A

lifts the ribs up

moves the sternum out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the mechanism by which the lifts move up and the sternum moves out called?

A

the bucket handle mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what effect does increasing the size of the lungs have on intra-alveolar pressure and why?

A

it decreases, because the air molecules are now contained in a larger volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

when does air stop entering the lungs in inspiration?

A

when the intra-alveolar pressure is equal to atmospheric pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does expiration occur?

A

passive

caused by relaxation of inspiratory muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens when the lungs recoil in expiration?

A

intra-alveolar pressure rises and air leaves the lungs down its pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

when does air stop leaving the lungs in expiration?

A

when intra-alveolar pressure is equal to atmospheric pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what two things cause the lungs to recoil during expiration?

A

elastic connective tissue in the lungs

alveolar surface tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a pneumothorax?

A

air in the pleural space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what are the three possible causes of a pneumothorax?

A

spontaneous
traumatic
iatrogenic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how can a pneumothorax progress to lung collapse?

A

air entering the pleural space can abolish the transmural pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what type of pneumothorax may be asymptomatic?

A

very small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

name two possible symptoms of a pneumothorax

A

shortness of breath

chest pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

name two possible signs of a pneumothorax

A

hyperresonant percussion

decreased breath sounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is alveolar surface tension?

A

the attraction between water molecules at the liquid air interface of an alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what does alveolar surface tension produce?

A

a force which resists the stretching of the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what reduces alveolar surface tension and prevents collapse?

A

surfactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

state laplace’s law

A

P=2T/r

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what does each letter in Laplace’s law represent?

A

P=inward directed pressure
T=surface tension
r-radius of alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

which size of alveoli has a higher tendency to collapse?

A

smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what cell produces surfactant?

A

type 2 alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

how does surfactant lower alveolar surface tension?

A

it intersperses between water molecules lining the alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

when do developing foetal lungs start to synthesise surfactant and what effect can this have?

A

late in pregnancy

premature babies might not have enough

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what causes respiratory distress syndrome of the new born?

A

lack of pulmonary surfactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

how does alveolar interdependence keep the alveoli open?

A

if one starts to collapse, the alveoli surrounding it are stretched and then recoil, exerting expanding forces on the one collapsing causing it to open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what factor most increases pulmonary ventilation?

A

tidal volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what are the major inspiratory muscles?

A

diaphragm

external intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what are the accessory muscles of inspiration?

A

sternocleidomastoid
scalenus
pectoral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

when do the accessory muscles of inspiration contract?

A

only during forceful inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what are the muscles of active expiration?

A

abdominal muscles

internal intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what is the tidal volume?

A

the volume of air entering/leaving the lungs during a single breath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is inspiratory reserve volume?

A

the extra volume of air that can be maximally inspired above tidal volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what is expiratory reserve volume?

A

the extra volume of air that can be expired beyond the tidal volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what is residual volume?

A

the volume of air remaining in the lungs, even after a maximal expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what is inspiratory capacity?

A

the maximum volume that can be inspired after a normal expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what do you get if you add IRV and TV?

A

inspiratory capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what is functional residual capacity?

A

the volume of air in the lungs at the end of a passive expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what do you get when you add ERV and RV?

A

functional residual capacity

54
Q

what is vital capacity?

A

the max volume of air that can be exhaled after a maximal inspiration

55
Q

what do you get when you add IRV + TV + ERV?

A

vital capacity

56
Q

what is total lung capacity?

A

the total volume of air the lungs can hold

57
Q

what do you get when you add VC + RV?

A

TLC

58
Q

what is the average value of TLC?

A

5700ml

59
Q

what volume cannot be measured by spirometry and what does this mean?

A

residual volume

means TLC also can’t be measured

60
Q

when does residual volume increase?

A

when elastic recoil of the lungs is lost

61
Q

name a disease where elastic recoil of the lungs is lost

A

emphysema

62
Q

name two dynamic lung volumes

A

FVC

FEV 1

63
Q

what does FVC stand for?

A

the forced vital capacity

64
Q

what is FVC?

A

the max volume that can be expired from the lungs after a max inspiration

65
Q

what is FEV1?

A

the volume of air that can be forcefully expired in the first second of expiration

66
Q

what is the FEV1/FVC ratio?

A

the proportion of the FVC that can be expired in the first second

67
Q

what is the normal value for the FEV1/FVC ratio?

A

over 70%

68
Q

what does a FEV1/FVC ratio under 70% suggest?

A

obstructive lung disease

69
Q

what are the dynamic lung volumes like in obstructive disease?

A 
FVC = normal 
FEV1 = low 
FEV1/FVC = low
70
Q

what are the dynamic lung volumes like in restrictive disease?

A 
FVC = low 
FEV1 = low 
FEV1/FVC = normal
71
Q

what are the dynamic lung volumes like in combined obstructive and restrictive disease?

A 
FVC = low 
FEV1 = low 
FEV1/FVC = low
72
Q

what equation can be used to calculate airway resistance?

A

F = deltaP/R

F = flow 
P = pressure 
R = resistance
73
Q

what is the main determinant of airway resistance?

A

the radius of the conducting airway

74
Q

what does parasympathetic stimulation of the bronchus cause?

A

bronchoconstriction

75
Q

what does sympathetic stimulation of the bronchus cause?

A

bronchodilation

76
Q

what happens to intrapleural pressure in inspiration?

A

falls

77
Q

what happens to intrapleural pressure in expiration?

A

rises

78
Q

what is a peak flow meter used for?

A

estimating peak flow rate, which assesses airway function

79
Q

what is pulmonary compliance?

A

a measure of the effort that goes into stretching or distending the lungs

80
Q

what is anatomical dead space?

A

areas in airways where gas exchange cannot occur

81
Q

how is pulmonary ventilation calculated?

A

tidal volume times RR

82
Q

why is alveolar ventilation less than pulmonary ventilation?

A

due to presence of anatomical dead space

83
Q

how is alveolar ventilation calculated?

A

(tidal volume - dead space volume) X RR

84
Q

what is pulmonary ventilation?

A

the volume of air breathed in and out per minute

85
Q

what is alveolar ventilation?

A

the volume of air exchanged between the atmosphere and the alveoli per minute

86
Q

how can pulmonary ventilation be increased?

A

increase depth and rate of brreathing

87
Q

what is ventilation?

A

the rate at which gas passes through the lungs

88
Q

what is perfusion?

A

the rate at which blood passes through the lungs

89
Q

what is alveolar dead space?

A

ventilated alveoli which are not adequately perfused with blood

90
Q

what is physiological dead space?

A

anatomical dead space + alveolar dead space

91
Q

what is the effect of decreased oxygen on pulmonary and systemic arterioles?

A

pulmonary = vasoconstriction

systemic = vasodilation

92
Q

what is the effect of increased oxygen on pulmonary and systemic arterioles?

A 
pulmonary = vasodilation 
systemic = vasoconstriction
93
Q

what is dalton’s law of partial pressure?

A

the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in the gas mixture

94
Q

what is PAO2?

A

the partial pressure of oxygen in alveolar air

95
Q

what is the alveolar gas equation?

A

PAO2 = PiO2 - [PaCO2/0.8]

96
Q

what is PiO2?

A

the partial pressure of carbon dioxide in inspired air

97
Q

what is PaCO2?

A

partial pressure of CO2 in arterial blood

98
Q

which is more soluble in membranes - CO2 or oxygen - and why?

A

CO2

diffusion coefficient for Co2 is 20x higher than oxygen

99
Q

what is the diffusion coefficient of a gas?

A

the solubility of the gas in membranes

100
Q

what is fick’s law of diffusion?

A

the amount of gas that moves across tissue in unit time is proportional to the area, but inversely proportional to its thickness

101
Q

what makes up the wall of the alveoli?

A

a single layer of flattened type I alveolar cells

102
Q

what is henry’s law?

A

the amount of a gas dissolved in a liquid at a constant temperature is proportional to the partial pressure of the gas in equilibrium with the liquid

103
Q

how is most oxygen transported in blood?

A

bound to haemoglobin in RBCs

104
Q

what are the two ways in which oxygen is present in blood?

A

bound to Hb

dissolved

105
Q

how many haem groups in each Hb molecule, and how many oxygen molecules can each haem group bind?

A

four

one oxygen molecule each

i.e. one Hb = four oxygen

106
Q

what is the main factor that determines Hb saturation with oxygen?

A

PO2

107
Q

what is meant by cooperativity as exhibited by haemoglobin?

A

binding of one oxygen increases affinity for oxygen

108
Q

what does the oxygen haemoglobin dissociation curve look like?

A

sigmoid curve

flattens when all sites occupied

109
Q

what is DO2I and how is it calculated?

A

the oxygen delivery index

CaO2 x CI (cardiac index)

110
Q

how much oxygen is carried by a fully saturated gram of Hb?

A

1.34ml

111
Q

what is CaO2 and how is it calculated?

A

the oxygen content of arterial blood

1.34 x [Hb] x Sa)2

112
Q

what is the bohr effect?

A

a shift of the oxygen Hb currve to the right

caused by increased release of oxygen

113
Q

what four factors can cause the bohr effect?

A

increased PCO2
increased [H+]
increased temperature
increases 23bpg

114
Q

describe the structure of foetal haemoglobin (HbF)

A

two alpha and two gamma subunits

has a higher affinity for oxygen

115
Q

when is HbF replaced?

A

within the first few months after birth

116
Q

where is myoglobin found?

A

skeletal and cardiac muscles

117
Q

how many haem groups are there per myoglobin molecule?

A

one

118
Q

describe the shape of the myoglobin dissociation curve

A

hyperbolic

119
Q

when does myoglobin release oxygen?

A

at very low Po2

this provides short term storage for oxygen for anaerobic conditions

120
Q

what does the presence of myoglobin in blood indicate?

A

muscle damage

121
Q

what are the three ways that CO2 can be transported in the blood and which is most common?

A 
in solution (least)
as bicarbonate (most common)
as carbamino compounds
122
Q

which is more soluble - CO2 or oxygen?

A

CO2 - around 20 times more soluble than oxygen

123
Q

what enzyme is involved in the formation of bicarbonate from CO2 and water?

A

carbonic anhydrase

124
Q

where does the formation of bicarbonate from CO2 and water occur?

A

in red blood cells

125
Q

how are carbamino compounds formed?

A

combining of CO2 with terminal amine groups in blood proteins

126
Q

name a carbamino compound

A

carbamino-haemoglobin

127
Q

what is the major rhythm generator of inspiration and expiration?

A

medulla

128
Q

what neurons generate the breathing rhythm?

A

the pre botzinger complex

129
Q

where is the pre botzinger complex located?

A

the upper end of the medullary respiratory centre

130
Q

what two groups of neurons in the pons can modify the breathing rhythm?

A

pneumotaxic centre

apneustic centre

131
Q

what does stimulation of the pneumotaxic centre do?

A

terminates inspiration

132
Q

what does stimulating the apneustic centre do?

A

prolongs inspiration

Y1 Respiratory (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions