Peer teaching Flashcards
1
Q
Which nerve innervates the diaphragm?
A
phrenic nerve
2
Q
What are the roots of the phrenic nerve?
A
C3 C4 C5
3
Q
How many lobes does the right lung have?
A
3
4
Q
How many lobes does the left lung have?
A
2
5
Q
What is the parasympathetic supply of the lungs?
A
the vagus nerve
6
Q
At what vertebral level is the carina?
A
T4/T5
7
Q
What is the anatomical surface marking of the horizontal fissure?
A
Right 4th rib
8
Q
What type of epithelium is respiratory epithelium?
A
ciliated pseudostratified columnar with goblet cells
9
Q
What type of pneumocyte forms most of the alveolar surface area?
A
Type 1
10
Q
Which type of pneumocyte is most numerous?
A
Type 2
11
Q
Which type of pneumocyte provides a thin barrier for diffusion?
A
Type 1
12
Q
What type of pneumocyte secretes surfactant?
A
Type 2
13
Q
What are the macrophages found in the lungs called?
A
Alveolar macrophages
14
Q
What is the fossa ovalis a remenant of?
A
the foramen ovale
15
Q
What is the function of the foramen ovale in the fetus?
A
hole between right and left atria. Allows blood to pass from right to left atrium
16
Q
What does the ductus arteriosus become?
A
the ligamentum arteriosum
17
Q
What does the ductus arteriosus connect in the fetus?
A
the pulmonary artery with the aorta. Allows bypass of the lungs
18
Q
What vessel does oxygenated blood from the placenta pass through to the fetus?
A
the umbilical vein
19
Q
Which gas is the predominant driver to breathe?
A
CO2
20
Q
Where in the brain will you find the pneumotaxic centre?
A
the pons
21
Q
Where in the brain will you find the apneustic centre?
A
the pons
22
Q
What is the function of the pneumotaxic centre?
A
involved in putting the breaks on inspiration
23
Q
What is the function of the apneustic centre?
A
moderates the effects of the pneumotaxic centre
24
Q
Which respiratory groups will you find in the medulla?
A
dorsal respiratory group, ventral respiratory group
25
When is the DRG predominantly active?
inspiration
26
When is the VRG predominantly active?
both inspiration and expiration
27
In the resting state, why is expiration largely passive?
recall of the thoracic wall
28
What are the central chemorecpetors primarily influenced by?
PaCO2
29
Where are the central chemorecpetors located?
In the brainstem at the pontomedullary junction
30
Why are the central chemoreceptors primarily inflenced by PaCO2?
blood brain barrier is relatively impermeable to H+ and HCO3-
31
Where will you find the peripheral chemoreceptors?
aorta - ascending aorta
| carotid bodies -bifurcation of the common carotid
32
What are the peripheral chemoreceptors influenced by?
PaCO2 PaO2 and pH
33
What does an increase in PaCO2 result in?
increased breathing rate
34
Describe the ventilatory response when there is normal PaO2 but raised PaCO2.
linear- increased PaCO2, increases breathing
35
Which type of chemoreceptor are responsible for all ventilatory responses to hypoxia ?
peripheral chemoreceptors
36
Give examples of lung receptors
stretch
J
irritant
37
Are stretch receptors in the lung slow or rapidly adapting?
slow adapting
38
Which two centres form the pontine respiratory group?
pneumotaxic centre and apneustic centre
39
What are the inputs to the respiratory control centres?
Central chemorecepetors
Peripheral chemoreceptors
Lung receptors
Muscle proprioceptors
40
What does the diaphragm do in inspiration?
contracts >> flattens >> increases volume of the thorax
41
What does perfusion refer to?
blood supply
42
How much is anatomic dead space?
150mls
43
How much is alveolar dead space?
25mls
44
what do we call alveolar dead space + anatomic dead space?
physiological dead space
45
How much is physiological dead space?
175mls
46
What is the average tidal volume?
500mls
47
When stood up, describe the perfusion of the lungs
preferential perfusion to the lower parts of the lungs
48
What is hypoxic mediated vasoconstriction?
Blood is diverted away from the parts of the lungs that don't have air in as blood vessels in these areas constrict . This is completely different to what happens in the systemic circulation!
49
What does PaCO2 mean?
partial pressure of CO2 in the arteries
50
What does PACO2 mean?
partial pressure of CO2 in the alveoli
51
PiO2 means?
pressure of inspired oxygen
52
V' A means? (should be a dot over the V)
Alveolar ventilation
53
V'CO2 means? ( should be a dot over the V)
CO2 production
54
What is the equation for CO2 elimination?
PaCO2= K V'CO2 / V'A
55
List three ways CO2 is transported in the body
bound to Hb
dissolved in the plasma
as carbonic acid
56
What is minute ventilation?
volume of air breathed per minute
57
Give some physiological causes of high PaCO2
Reduced minute ventilation- V'A reduced
Rapid shallow breathing resulting in increased dead space ventilation and reduced V'A
Increased dead space as a result of ventilation perfusion mismatch. (V/Q mismatch)
Increased CO2 production (V'CO2)
58
What is the alveolar gas equation?
PAO2 = PiO2 - PaCO2 / R
59
What is the normal blood pH range?
7.35-7.45
60
What is the carbonic acid equilibrium equation?
CO2 + H2O <> H2CO3 <> H+ = HCO3-
61
What is the henderson-hasselbach equation?
pH = 6.1 log10 ([HCO3-] / [0.03xPCO2])
62
What happens to HCO3- in a chronically acidotic patient ?
HCO3- increases ( more HCO3- absorbed at kidneys)
63
What are the 4 main acid-base disorders?
Respiratory acidosis
Respiratory alkalosis
Metabolic acidosis
Metabolic alkalosis
64
In respiratory acidosis what would you see happen to PaCO2, pH and HCO3-
PaCO2 increased
pH decreased
HCO3- mild increase
65
In respiratory alkalosis what would you see happen to PaCO2, pH and HCO3-?
PaCO2 decreased
pH increased
HCO3- mild decrease
66
What do you see in metabolic acidosis?
reduced HCO3-
| reduced pH
67
What would you see in metabolic alkalosis?
increased HCO3-
| increased pH
68
What is the respiratory quotient approximately?
0.8
69
What does FRC stand for in spirometry?
functional residual capacity
70
What does VC stand for in spirometry?
vital capacity
71
What does TLC stand for in spirometry?
Total lung capacity
72
What is vital capacity (VC)?
the maximum amount of air a person can expell from the lungs after a maximum inhalation
73
What is tidal volume?
amount of air breathed in with each normal breath
74
What is total lung capacity ?
Maximum amount of air that can fill the lungs
75
What is the total lung capacity of an adult male?
6L
76
What is functional residual capacity?
the volume of air present in the lungs after passive expiration
77
What is residual volume?
the volume of air that remains in the lungs after maximum forceful expiration
78
What is FVC?
forced vital capacity
79
What is forced vital capacity ?
forced expiratory volume irrespective of time
80
What is FEV1?
Forced expiratory volume in one second
81
Vital capacity + ? = total lung capacity ?
residual volume
82
what does PEF stand for?
peak expiratory flow
83
What are transfer estimates referring to?
the transfer of gas from the alveolus to the alveolar capillaries
84
What is DLCO?
diffusion capability for carbon monoxide
85
What percentage of predicted FEV1 can a patient have a still be considered normal?
more than 80% of predicted FEV1
86
What percentage of the predicated value does FVC have to be to be considered normal?
more than 80% of predicated FVC
87
What is an obstructive lung disease?
a condition that makes it hard to exhale all the air from the lungs
88
What is a restrictive lung disease?
difficulty fully expanding the lungs with air
89
Is asthema obstructive or restrictive?
obstructive
90
What ratio do we look at when testing for airways obstruction?
FEV1/FVC ratio
91
What is an abnormal FEV1/FVC ratio?
below 0.7
92
What does a ratio of FEV1/FVC below 0.7 indicate ?
obstructive lung disease
93
What is the name for increased CO2 levels in the blood?
hypercapnia
94
Describe type 1 respiratory failure
Lung failure
PO2 is low
PCO2 is low or normal
95
Describe type 2 respiratory failure
Pump failure
PO2 is low
PCO2 is high
96
What type of respiratory failure when alveoli fill with fluid such as water, blood or pus?
type 1
97
What type of respiratory failure could you see in an asthema attack?
type 2
98
What is type 1 respiratory failure also referred to as?
hypoxemic
99
What is type 2 respiratory failure also referred to as?
hypercapnic
100
What is low oxygen defined as?
PO2 less than 8KPa
101
What is high CO2 defined as?
CO2 greater than 6KPa
102
What does the Q stand for in V/Q mismatch?
perfusion
103
How many zones do we usually divide the lung into when referring to ventilation and perfusion?
3 zones
104
In which zone of the lung will you find the largest alveoli ?
zone 1
105
Which zone is found at the apex of the lung?
zone 1
106
What is the average V/Q ratio?
0.8
107
When standing up, which part of the lung gets greater perfusion?
the lowest portion- zone 3
108
When standing up, which part of the lung has the best ventilation?
the lowest portion-zone 3
109
Which portion of the lung has the lowest V/Q ratio?
the lowest portion- zone 3. ( this area has the greatest perfusion)
110
What portion of the lung has the highest V/Q ratio?
the upper portion- zone 1 (the apex)
111
What does PA mean?
alveolar pressure
112
What does Pv mean?
venous pressure
113
What does it mean when there is an absolute pulmonary shunt. What is the V/Q ratio when this occurs.
No ventilation!
| V/Q=0
114
What would the be the effect of pneumonia be on the V/Q ratio?
decrease ventialtion
| therefore decrease the V/Q ratio
115
Put Pa PA and Pv in order for zone 1 of the lung
PA>Pa>Pv
116
Put Pa PA and Pv in order for zone 2
Pa>PA>Pv
117
Put Pa PA and Pv in order for zone 3 of the lung
Pa>Pv>PA
118
What is a pulmoary embolism?
clot travels to the lungs
119
What are the corners of Virchow's triad?
circulatiory stasis, endothlial injury and hypercoaguable state
120
Which type of antibodies are made at the start of an infection and are not very specific?
IgM
121
What is IgE made in response to?
allergens
122
Describe type 1 hypersensitivity reactions
antigens bind to IgE on mast cells/basophils
| e.g anaphylaxis, allergy, asthma
123
Describe type 2 hypersensitivity reactions
cytotoxic T cells killing
| e.g transfusion mismatch, goodpasture's syndrome
124
Describe type 3 hypersensitivity reactions
IgG forms immune complexes
| e.g lupus, systemic lupus erthematosis
125
Describe type 4 hypersensitivity reactions
Delayed T helper cells activate macrophages
| e.g contact dermatitis
126
List the barriers to diffusion in the alveolus
1. Surfactant
2. Layer of epithelial cells- type 1 pneumocytes
3. Basement membrane of type 1 pneumocytes
4. Interstitial space
5. Basement membrane
6. Endothelia
7. Erythrocyte
127
What is on the x axis of an oxygen dissociation curve?
partial pressure of O2
128
What is on the y axis of an oxygen dissociation curve?
% oxyhaemoglobin saturation
129
What is hypoxia?
deficiencyH of O2 at tissue level
130
How many types of hypoxia are there?
4
131
What is the most common type of hypoxia?
hypoxemia (hypoxic hypoxia)
132
What type of hypoxia might high altitude, hypoventilation or V/Q mismatch cause?
hypoxemia (hypoxic hypoxia)
133
Ischaemic hypoxia occurs as a result of decreased what?
perfusion
134
What is cellular hypoxia referred to as?
histotoxic hypoxia
135
What are the 4 types of hypoxia?
hypoxemia (hypoxic hypoxia)
anaemia
ischemic hypoxia
histotoxic hypoxia
136
What are the causes of hypoxemia?
hypoventilation
Diffusion impairment
V/Q mismatch
Shunting
137
What is the affect of DPG on haemoglobin's affinity to oxygen?
increased DPG decreases haemoglobins affinity for oxygen
138
When Hbs affinity for oxygen decreases, which way does the oxygen dissociation curve shift?
right
139
What factors decrease Hbs affinity for oxygen?
increase in DPG
increase in temperature
increase in acidity
140
Why is does haemoglobin at more metabollically active tissues give up oxygen molecules more readily?
Temperature is higher at more metabolically active tissues
| Greater PCO2 at more metabolically active tissues
141
What is special about fetal haemoglobin?
Has a higher affinity for oxygen than adult haemoglobin
