respiration Flashcards
(184 cards)
1
Q
what does the lungs do?
A
- brings in fresh air rich with oxygen
- expels waste gases produced in body
2
Q
where do the upper airways conduct blood do?
A
lung
3
Q
what is the function of upper airways carrying blood to lung?
A
humidify
warm
filter
4
Q
what epithelium are upper airways lined with?
A
pseudo stratified ciliated columnar epithelium
5
Q
what epithelium are upper airways lined with?
A
pseudo stratified ciliated columnar epithelium
6
Q
where are goblet cells found in the respiratory tract and what is their purpose?
A
sit between epithelial layers and produce mucous
7
Q
how are inhaled particles stopped from entering the respiratory?
A
stick to mucous
8
Q
how is mucous in the upper airways moved towards the mouth?
A
cilia
9
Q
what level of breathing is required in healthy lungs?
A
low level with small muscle effort
10
Q
why is high intensity breathing less efficient?
A
as the air is turbulent therefor more muscles used and the muscles fatigue more easily
11
Q
what does respiratory muscle fatigue lead to?
A
respiratory muscle failure
12
Q
at rest what is the partial pressure of oxygen in a healthy individual?
A
100 mmhg
13
Q
at rest what is the partial pressure of carbon dioxide in a healthy individual?
A
40 mmhg
14
Q
during rest what is the amount of o2 and co2 exchanged?
A
250ml o2
200ml co2
15
Q
during walking what is the amount of 02 and co2 exchanged?
A
800ml o2
200ml co2
16
Q
during excerise what is the amount of 02 and co2 exchanged?
A
5000ml o2
6000ml co2
17
Q
what is the volume of ventilation at rest?
A
6-7 litres per min
18
Q
during quiet breathing is inspiration and expiration passive or active?
A
inspiration = active
expiration = passive
19
Q
during strenuous breathing is inspiration and expiration passive or active?
A
inspiration = active
expiration = active
20
Q
what happens in inspiration during quiet breathing?
A
diaphragm contracts down pushing abdominal contents out
and external intercostals pull ribs out and up
21
Q
what happens in expiration during quiet breathing?
A
elastic recoil
22
Q
what happens in inspiration during strenuous breathing?
A
diaphragm and intercostals contract more
- inspiratory accessory muscles are activated
23
Q
give 2 examples of inspiratory accessory muscles?
A
sternocleidomastoid and alae nasi
24
Q
what happens in expiration during strenuos breathing?
A
contraction of abdominal muscles
and internal intercostals oppose external by pulling ribs in and down
25
what makes the inspiratory capacity?
tital volume + inspiratory reserve volume
26
what is the vital capacity?
huge breath in then breathe it all out
27
what is the functional residual capacity?
volume left after a normal breathe out
28
what is the inspiratory reserve volume?
after taking a breath in, breath in even more
29
what is tissue respiration?
aerobic metabolism in cells
30
what is the intrapulmonary pressure?
pressure in the lungs
31
what is the intraplural pressure?
pressure between the lungs and the chest wall
32
what is the tidal volume? + value
volume change in lung when breath taken in
usually 1/2 litre
33
what is the barometric pressure?
pressure outside the lungs
34
what is the transpulmonary pressure?
difference between the pressure inside the lung and pleural space
35
what does elastic recoil force the lung to do?
breath out
- decrease lung volume
36
what does outward recoil force the lung to do?
take breath in
37
at FRC what is the ratio of outward and elastic recoil?
equal
38
at function residual capacity what is the state of the lung?
relaxed
39
what happens to the FRC when chest wall is weak?
decreases
40
when chest wall muscles are weak what happens to the elastic recoil?
greater
41
what effect would neuromuscular disease have on the chest walls?
makes them weak
42
what is the expiratory reserve volume?
breathing out the FRC
43
at the beginning of inspiration Pa (alveolar pressure) is what and why?
0 because there is no flow
44
what happens when the muscles contract during inspiration?
pleural and alveolar pressures decrease
glottis opens
air flows into the lung
45
what is the pressure gradient of air flowing into the lung?
high to low pressure
46
when does flow into the lung stop?
when atmospheric and alveolar pressure is equal
glottis closes
47
what is the barometric pressure and alveolar pressure at the start of inspiration?
0
48
what happens to the thoracic volume at the beginning of expiration?
decreases
49
what is the ratio of aveolar pressure and barometric pressure during expiration?
Pa > Pb
50
what does the sum of partial pressures =
total pressure
51
what is the equation for partial pressure in the mouth?
fraction of gas in the mixture X barometric pressure
Gas X Pb
52
where does the pulmonary circulation bring blood from and to?
deoxy blood from heart to lungs
oxygen blood from lungs to heart
53
what is the pressure of blood in pulmonary circulation?
low
54
where does bronchial circulation carry blood from and to?
oxygen blood to lung parenchyma
55
what is the function of the bronchial artery?
provides blood to lung to allow cells and tissues to function
56
what is the function of the lymphatics system?
defence and removal of lymph fluid
57
how much blood does the pulmonary circulation contain?
500ml
58
what are the 2 parts of the respiratory tree?
conducting airways and the respiratory airways
59
as airways branch, what happens to the bronchioles?
they get a smaller diameter and more numerous to cover a larger surface area for gas exchange
60
where do bronchioles carry o2 to?
alveolar sacs
61
how much blood is in the conducting airways?
150ml
62
how much blood is in the respiratory airway?
2500ml
63
what airway does gas exchange occur?
respiratory airways
64
what is the purpose of the conducting airways?
carry air to the lung
65
what is the alveolar dead space? what % of air is found here?
conducting airways 30%
66
what type of epithelium is majority of the alveoli covered by? %
type 1 97%
67
what type of epithelium is present where gas exchange occurs?
type 1
68
what is the function of type 2 epithelium in the alveoli?
produce pulmonary surfactant to reduce friction
69
what are the cells called that are covered by type 2 epithelium in the alveoli?
septal cells
70
what do alveolar macrophages do?
reduce debris
71
why are the alveoli great for gas exchange?
they have thin walls
large surface area
72
where is the alveolar capillary network found? how thick is it?
between alveolar air space and RBC
1-2um
73
what is between the endothelium and alveolar epithelium in a capillary?
how thick is this layer
endothelial cells and basal lamina 0.5um
74
how quickly do RBCs pass through a capillary?
<1 second
75
at rest how much blood is in the alveolar capillary network?
75ml
76
during exercise how much blood is in the alveolar capillary network?
150-200ml
77
why does the amount of blood in the alveolar capillary network increase during exercise?
as new capillaries are recruited to deal with the increased pressure and flow
78
give features of pulmonary arteries that make them different to other arteries ?
thin walls
arge diameter
low resistance
79
in pulmonary circulation what is the flow of o2 and co2?
o2 enter
co2 leaves
80
in the systemic circulation what is the flow of o2 and co2?
co2 enters and o2 leaves to go to tissues
81
why do similar volumes of o2 and co2 move each minute even though there is les co2?
co2 is more diffusable
82
what are the 2 forms of oxygen transport?
dissolved o2
and o2 bound to haemoglobin
83
what is the most effective way of oxygen transport?
bound to hg
84
how much dissolved o2 is transported per minute?
15ml
85
describe a haemoglobin molecule?
2 alpha chains
2 beta chain
and 4 haem groups
86
where does o2 bind on a haemoglobin molecule?
fe2+ on the haemorrhage groups
87
how many molecules of o2 can 1 haemoglobin bind?
4
88
what effect does a drop in partial pressure below 60mmhg have on o2 binding hg?
o2 begins to release from hg into tissue
89
what environmental factors effect o2 binding to hg?
temp and ph
90
1g of hg binds with how many ml of o2?
1.39
91
what is the total o2 carrying capacity in blood
211ml per litre of blood
92
how do you measure the oxygen saturation?
pulse oximeter
93
how does a pulse oximeter work?
measure the ratio of absorption of red and infrared light to oxygenated and deoxygenated blood
94
what happens after co2 diffuses into a RBC?
converted to carbonic acid and dissociates into bicarbonate and hydrogen ions
95
what does a chloride pump do when co2 diffuses into RBCs?
bicarbonate moves out and is replaced by chlorine
96
how are the hydrogen ions removed after a co2 diffuses into a RBS?
buffers
97
how do you regulate the acidity of blood?
use ventilation to adjust the partial pressure of co2
use kidney to regulate the bicarbonate concentration
98
Henderson hasselbach equation????
99
during respiration where does the brain receive neural signals from?
mechanoreceptors and chemoreceptors
100
what do chemoreceptors provide to the brain in respiration?
partial pressure of o2 co2 and ph of blood
101
what do mechanoreceptors provide the brain in respiration?
feedback on mechanical status on lung, chest wall and airways
102
after the brain receives neural signals where does it send the signals to?
upper airways and respiratory muscles
103
what do the respiratory muscles do after receiving neural signals from the brain?
rhythmic breathing
104
what do the upper airways do after receiving neural signals from the brain?
provide reflexes to keep airways clear
105
what are chemoreceptors in terms of respiration?
sensory receptors that detect chemical changes in environment
106
what is hypoxia?
not enough o2 to maintain homeostasis and carry out metabolic function
107
what is the Po2 in hypoxia?
<60mmhg
108
what is hypercapnia?
too much co2 in the blood
109
what is the Pco2 in hypercapnia?
>40mmg
110
what is hypocapnia?
decreased co2 in the blood
111
what is the Pco2 in hypocapnia?
<35mmhg
112
where are peripheral chemoreceptors found?
aortic arch
carotid sinus
113
how do peripheral chemoreceptors send their information and to where ?
via glossopharyngeal and vagus nerves to nucleus in the brainstem
114
how do peripheral chemoreceptors respond to hypoxia?
- stimulated
- send neural signals to NTS
- increase ventilation
115
what happens if peripheral chemoreceptors detect Po2 below 60mmhg?
hyperventilation
116
what effect do small changes in co2 have on ventilation?
large effect
117
what is the NTS?
nucleus tractus solitarius
118
where is the NTS found in the brainstem?
dorsal medulla
119
when are central chemoreceptors activated?
hypercapnia
120
how to central chemoreceptors respond to hypercapnia?
- activated
- pass info to neuronal clusters in brainstem
- increase ventilation
121
what is the motor homunculus?
areas of motor cortex for muscle is proportional to the number of motor neurons innervating that muscle
122
what do inputs from the upper brain do? (cerebral cortex)
volitional and emotional breathing
123
what are mechanical receptors in terms of respiration?
sensory receptors that detect pressure, movement and touch change
124
what do mechanoreceptors do when the lung inflates?
- activate
- send signals along vagus nerve to NTS
- adjust ventilation
125
where are mechanoreceptors found in the upper airways?
1. airway smooth muscle
2. airway epithelium
126
what is the reflex of mechanoreceptors in the airway smooth muscle when the lung inflates?
terminates the inspiration
127
what is the reflex of mechanoreceptors in the airway epithelium when there is rapid lung inflation or oedema?
sigh or a short expiration
128
what is oedema in the respiratory system?
build up of fluid in the lungs
129
what neurons are found in the ventral respiratory groups?
rhythm generating neurons
pattern generating neurons
130
what is found in the dorsal respiratory groups?
NTS and neurons that get input form chemoreceptors and mechanoreceptors
131
what is perfusion?
process of deoxygenated blood moving through lung to become oxygenated
132
what does the VQ relationship determine?
Po2
Pco2
gas exchange
133
what is the physiological dead space?
volume of gas in each inspiration that doesn't do gas exchange
134
how does gravity influence the pulmonary blood flow when standing upright?
greater blood flow to the apex of the lung than the base
135
what is the distribution of ventilation in the alveoli when standing upright?
alveoli in the apex more spread out than in the base so more blood to apex
136
what way does gravity pull the lung?
down and away from the chest wall
137
what is the pleural pressure like at the apex compared to base?
more negative
138
what is the transpulmonary pressure like at the apex compared to base?
greater
139
what is the alveolar pressure like at the apex compared to the base?
greater
140
what is an anatomical shunt?
mixed venous blood shunted into arterial blood
141
what is an shunt in the lung?
pulmonary artery blood shunted into pulmonary vein
142
what happens to the alveolar ventilation during a shunt in the lung?
stays the same
143
what happens to the distribution of blood flow during a shunt in the lung?
changes
144
what happens to the Po2 during a shunt in the lung?
varies depending on size of shunt
145
what is a right to left shunt?
blood shunted from the RA/V across the septum to the LA/V
146
what does a right to left shunt result in?
hypoxemia
147
what is hypoxemia?
levels of oxygen in the blood below normal
148
in a right to left shunt why is co2 not increased?
chemoreceptors increase ventilation to reduce it
149
what is lung compliance?
how much effort required to stretch lungs and chest wall
150
if compliance increase how easily does the chest and lung walls stretch?
more easily
151
if compliance decreases how easily does the chest and lung wall stretch?
less easily
152
decreased compliance is a feature of many pulmonary conditions such as?
tuberculosis - scaring of the lung tissue
oedema - lungs filled with fluid
emphysema - destruction of elastic fibres
deficiency in surfactant produced
153
what conditions would increased resistance be a feature of?
asthma
COPD
154
what would decreased resistance cause in the lung?
no turbulence
(large diameter)
155
what is the VQ ratio?
ratio of ventilation to blood flow
156
what is the VQ ratio defined as in a single alveolus?
alveolar ventilation/ capillary flow
157
what is the VQ ratio in the lung defined as?
total alveolar ventilation/cardiac output
158
what is the VQ ratio in a healthy lung?
0.8 to 1.2
159
what does it mean if the VQ ratio is > 1 ?
ventilation exceeds perfusion
160
what does it mean if the VQ relationship is <1?
perfusion exceeds ventilation
161
what does VQ mismatching cause?
atrerial hypoxema
162
what is arterial hypoxema?
below normal level of oxygen in the blood
163
what is the value of Po2 for arterial hypoxema?
<80mmhg
164
what is a physiological shunt? and what is the VQ ratio
ventilation to lung units absent in presence of continuing perfusion
VQ = 1
(non ventilated alveoli remain perfused)
165
what does a physiological shunt cause?
because mixed blood is continuing to be perfused through the alveoli and there is no oxygen to oxygenate it
- the mixed blood moves out into arterial blood
166
what is ateleoclasis?
obstruction of ventilation due to mucous plugs, oedema, foreign bodies or tumours in the airways
167
what causes chronic obstructive pulmonary disease COPD?
long term smoking
168
what are symptoms of chronic obstructive pulmonary disease COPD?
shortness of breath, cough, tight chest, increased mucous
169
what is emphysema?
inflation of structures in the alveoli
170
what are symptoms of emphysema?
inhale but struggle to exhale due to decreases elastic recoil
171
what happens to the lungs in emphysema?
lungs loose elasticity so can't fully expand or contract
172
what is chronic bronchitis?
inflammation of the bronchi
173
what are symptoms of chronic bronchitis?
shortness of breath and more susceptible to chest infection
174
what causes inflammation of the bronchi in chronic bronchitis?
increases mucous production and excessive swelling
175
what is pulmonary fibrosis?
interstitial lung disease
176
what happens to the lung tissues in pulmonary fibrosis?
scarring and thickening
177
what does pulmonary fibrosis cause in the lungs?
decreased elasticity and gas exchange
178
how do you measure lung volume?
vitalograph or spirograph
179
what would you ask the patient to do when measuring lung volume?
inhale as much as possible then exhale as fast as possible
180
in health the forced expiratory volume/ the forced vital capacity ratio should be?
>70%
181
in obstructive lung disease the forced expiratory volume/ the forced vital capacity ratio should be?
<70%
182
in restrictive lung disease the forced expiratory volume/ the forced vital capacity ratio should be?
>70%
183
give examples of an obstructive pulmonary disease?
emphysema
asthma
pulmonary oedema
184
give examples of a restrictive pulmonary disease?
pulmonary fibrosis
neuromuscular disease
respiratory distress syndrome
