Download Respiratory Physiology Questions

Respiratory Physiology Questions
1.
Increased baroreceptor discharge acts via the medulla to:
a.
b.
c.
d.
e.
2.
c.
d.
e.
50% is in the dissolved form
The Haldane effect is the fact that oxygenation of the blood increases
its ability to carry CO2
Ionic dissociation of carbonic acid requires the presence of carbonic
anhydrase to be a fast process
An increase in pCO2 in blood shifts the oxygen dissociation curve to
the left
Approximately 30% of the venous-arterial difference is attributable to
the carbamino compounds
Regarding conduction in the heart
a.
b.
c.
d.
e.
5.
Erythropoietin secretion rises after 2 – 3 days
Nifedipine alleviates the symptoms of mountain sickness
Alveolar pCO2 levels rise
pCO2 levels fall because of decreased oxygen content of the air
Initially the O2Hb dissociation curve shifts to the left
Regarding CO2 transport in blood
a.
b.
4.
heart rate
stroke volume
vessel diameter
blood pressure
renin secretion
On Climbing Everest
a.
b.
c.
d.
e.
3.
Increase
Increase
Increase
Increase
Increase
Stimulation of right vagus inhibits the AV node
The rate of discharge of the SAN is independent of temperature
Depolarisation of ventricular muscle starts on the right
The speed of conduction is fastest in ventricular muscle
The SA node and AV node exhibit the same speed of conduction
The alveolar gas equation
a.
b.
c.
d.
e.
Is also known as Bohr’s equation
Can be used to calculate anatomical dead space
Is influenced by diet
Is independent of PiO2
Requires sampling of gas to determine PaCO2
6.
Regarding ventilation during exercise
a.
b.
c.
d.
e.
7.
Oxygen transport
a.
b.
c.
d.
e.
8.
d.
e.
b.
c.
d.
e.
In healthy individuals, anatomical dead space is less than physiologic
dead space
The relative change in blood flow from apex to base is less than
relative change in the ventilation
Ventilation/perfusion differences are due to gravity
Ventilation/perfusion ratio is low at the base
All of the above
For the chemical control of respiration
a.
b.
c.
d.
e.
11.
The autonomic control centre is located in the midbrain
Brainstem respiratory neurons only discharge during inspiration
Arterial PaO2 must be below 80mmHg to produce increased discharge
from peripheral chemoreceptor
Medullary chemoreceptors monitor O2 concentration in the CSF
In metabolic alkalosis ventilation is depressed
Regarding ventilation/perfusion differences in the lung
a.
10.
The oxygen dissociation curve shifts left with a fall in pH
More oxygen is supplied to tissues by a fall in 2,3DPG levels
2,3 DPG levels are increased by ascent to 7,000 metres
2,3 DPG levels in stored blood increase
Oxygen dissociation curve shifts right with a drop in temperature
With regards to ventilation
a.
b.
c.
9.
Pulmonary blood flow is increased from 5.5l/min to 55l/min
Abrupt increase in ventilation at onset of exercise is due to increased
respiratory rate
Increases in ventilation are proportionate to increase CO2 production
CO2 excretion increases from 200ml/min to up to 8000ml/min
There is a fall in blood pH during moderate exercise
The carotid bodies respond to changes of pH, pO2 , pCO2
The aortic bodies respond to changes of pH, pO2 , pCO2
pO2 is only detected by the central chemoreceptors
Severe hypoxia strongly stimulates the central chemoreceptors
The central chemoreceptors respond to changes in plasma pH
In the cardiac cycle
a.
b.
c.
d.
e.
Right ventricular contraction occurs before left
Phase II commences with the opening of the AV valves
Phase IV is isovolumetric relaxation
During inspiration, the pulmonary valve closes before the aortic
The duration of systole is more variable than diastole
12.
Cerebral circulation
a.
b.
c.
d.
e.
13.
An arterial blood gas taken from a patient breathing room air at sea level
shows a pCO2 20, pO2 60, pH 7.52. Assuming a normal respiratory quotient,
calculate the alveolar pO2
a.
b.
c.
d.
e.
14.
Stimulating pulmonary stretch receptors
Stimulating central chemoreceptors
Inhibiting peripheral chemoreceptors
Stimulating J receptors in alveolar walls
Increasing CSF pH
As a percentage of total blood volume, which of the following values are
correct
a.
b.
c.
d.
e.
17.
Capillary pressure at the arteriole end is 15mmHg
Hydrostatic pressure exceeds oncotic pressure throughout the capillary
Capillary pressure at the venule end is 5mmHg
Interstitial colloid osmotic pressure is usually negligible
Capillary filtration coefficient decreases with capillary permeability
CO2 can increase respiration by:
a.
b.
c.
d.
e.
16.
80mmHg
85mmHg
150mmHg
130mmHg
125mmHg
Regarding Starlings forces
a.
b.
c.
d.
e.
15.
Is highly variable with posture
Is constant across approximately 100-200mmHg
Is variable due to the “closed box” nature of the cranium
Is approximately 750ml/min
Has the same flow/weight ratio as the kidney
40% is in the pulmonary circulation
13% is in the systemic arteries
20% is in the systemic arterioles and capillaries
30% is in the veins
None of the above are correct
Beta-1 receptor mediated increase in cardiac firing rate occurs
a.
b.
c.
d.
e.
G protein related increased K+ conductance
G protein related increased Ca++ conductance
G protein related decreased K+ conductance
cAMP related increased Ca++ conductance
cAMP related K+ conductance
18.
Vagal stimulation of SA node
a.
b.
c.
d.
e.
19.
With respect to central nervous system control of the heart
a.
b.
c.
d.
e.
20.
Leads to increased conductance of Ca++ into the cell
Leads to increased conductance of K+ into the cell
Leads to raised intracellular cAMP
Decreases the slope of the prepotential of the SA node
Inhibits the B-1 receptor directly
Sympathetic stimulation can increase cardiac out put nine-fold from
the resting state
In the absence of parasympathetic input, sympathetic inhibition of the
heart results in a 30% decrease in heart rate
Vagal stimulation can override sympathetic stimulation
Sympathetic input is predominantly to the SA node, while
parasympathetic input is predominantly to the AV node
All of the above
Blood pressure
a.
b.
c.
d.
e.
Fluctuates in the aorta between 180 and 20mmHg
Is approaching 0mmHg at the right atrium
Is half in the pulmonary arteries of that in the aorta
Is greater in large veins than vena cava
Drops most significantly at capillary level
Respiratory Physiology Dec 06 Answers
1.
C
2.
E
3.
E
4.
E
5.
C
6.
D
7.
C
8.
E
9.
D
10.
A
11.
C
12.
D
13.
D
14.
D
15.
B
16.
B
17.
D
18.
D
19.
B
20.
B