MCQ

Question 1

What pressure opens aortic valve

Answer 1

80mmHg

Question 2

How many times bigger is left ventricular wall to right?

Answer 2

3x

Question 3

Describe the effect of venous pressure on volume

Answer 3

The initial graph is very steep between 0 and 10mmHg due to the large capacitance of the vessels

Question 4

Pressure at venules vs larger veins

Answer 4

12-20mmHg in venues, 10mmHg in large veins like femoral/axillary

Question 5

How is physiological dead space calculated?

Answer 5

Bohr Equation

Question 6

What is the Bohr equation?

Answer 6

For ease of measurement, PACo2 equal to PaCO2. PECO2 equal to PETCo2

Small a = arterial, capital A = alveolar

Question 7

What is normal value for Vd/Vt (Bohr equation)?

Answer 7

0.2-0.35

Question 8

Why does blood flow increase in dependent area of lung?

Answer 8

Gravity increases perfusion pressures in lungs by 1cm H20 for every 1cm below level of heart. Therefore increased hydrostatic pressure

Question 9

What is Fick equation for CO calculation?

Answer 9

Question 10

Describe make up of polypeptides in adult Hb and fatal Hb

Answer 10

HBA (two alpha two beta), 2-3% is HbA2 (two alpha two delta).

Fetal = two alpha, two gamma

Question 11

What type of iron is in Hb

Answer 11

Ferrous (Fe2+)

Question 12

What is Bohr effect?

Answer 12

As co2 rises, affinity for O2 falls in Hb

Question 13

What is Haldane effect?

Answer 13

Deoxygenated Hb has greater affinity for CO2

Question 14

Why does rectal administration increase bioavailability?

Answer 14

Avoid first pass

Question 15

Chemical form of thiopental

Answer 15

sulphur analogue of the oxybarbituate pentobarbital

Question 16

How much of thiopental is availble in the active form in humans?

Answer 16

12% is unionised and not protein bound

Question 17

Blood gas co-efficient for Xenon

Answer 17

0.14 - very low, thus onset/offset is faster than Des/Sevo/N2O

Question 18

What is first perfect gas law?

Answer 18

Boyle’s law

Question 19

What is Boyles law

Answer 19

At a constant temp, the volume of a gas is inversely proportional to the pressure

Question 20

What us second perfect gas law?

Answer 20

Charle’s law

Question 21

What is Charles’ law

Answer 21

At a constant pressure, the volume of a gas is directly proportional to the temperature

Question 22

Third gas law?

Answer 22

At a constant volume, the absolute pressure of a gas is directly proportional to the temperature

Question 23

What is the perfect gas equation?

Answer 23

Constant = (PxV)/T

Question 24

What are gas laws corrected to?

Answer 24

Standard temp: 273.15K (0 degrees celsius)
Standard pressure: 101kPa

Question 25

What is the temperature of water’s triple point?

Answer 25

273.16K (0.01C)

Question 26

Describe the flow nearest the wall in laminar flow and flow in the centre

Answer 26

near wall: It has no flow
Centre: twice the velocity of the average flow

Question 27

Why is nitrous a liquid in cylinders?

Answer 27

Boiling point -88, Critical temp 36.5, therefore it is a liquid with a vapour layer above

Question 28

what is nitrous filling ratio?

Answer 28

0.75

Question 29

How accurate are flowmeters?

Answer 29

accurate to within 2.5%

Question 30

What reduces accuracy of flowmeters?

Answer 30

Dirt in conical tube
static electricity build up
back pressure from common gas outlet

Question 31

Which heart sounds correspond to which parts on QRS

Question 32

Describe pressure in RA, LA, RV, LV