Physiology

Question 1

what is Boyle’s law

Answer 1

At any constant temperature the pressure exerted by a gas varies inversely with the volume of the gas.

Question 2

how is intra-pleural pressure affected by inspiration and expiration

Answer 2

Inspiration - falls

Expiration - rises

Question 3

what is LaPlace’s Law

Answer 3

P=2T/r
where 
P = inward directed collapsing pressure
T = surface tension
r = radius of the bubble

Question 4

what is FVC and FEV1

Answer 4

forced vital capacity (max volume forcibly expelled from lungs following max inspiration)
forced expiratory volume in 1 sec

Question 5

what is pulmonary ventilation

Answer 5

volume of air breathed in and out per minute

Question 6

what is alveolar ventilation

Answer 6

volume of air exchanged between the atmosphere and alveoli per min

Question 7

what is ventilation

Answer 7

the rate at which gas is passing through the lungs.

Question 8

what is perfusion

Answer 8

the rate at which blood is passing through the lungs

Question 9

what does V/Q measure

Answer 9

Ventilation compared to perfusion

Question 10

what is the term for when alveoli well ventilated but not well perfused

Answer 10

alveolar dead space

Question 11

what does decreased oxygen cause in the pulmonary and systemic arterioles

Answer 11

Pulmonary - vasoconstriction

Systemic - vasodilation

Question 12

what does increased oxygen cause in the pulmonary and systemic arterioles

Answer 12

Pulmonary - vasodilation

Systemic - vasoconstriction

Question 13

what is Dalton’s law of partial pressure

Answer 13

The total pressure exerted by a gaseous mixture = The sum of the partial pressures of each individual component in the gas mixture

Question 14

what is partial pressure of a gas

Answer 14

pressure that one gas in a mixture of gases would exert if it were the only gas present in the whole volume occupied by the mixture at a given temperature

Question 15

what is Fick’s Law of diffusion

Answer 15

The amount of gas that moves across a sheet of tissue in unit time is proportional to the area of
the sheet but inversely proportional to its thickness.

Question 16

what is Henry’s Law

Answer 16

The amount of a given gas dissolve in a given type and volume of liquid (e.g. blood) at a constant temperature is proportional to the partial pressure of the gas in equilibrium with the liquid

Question 17

what does Henry’s Law mean

Answer 17

that if the partial pressure in the gas phase is increased the concentration of the gas in the liquid phase would increase proportionally

Question 18

what is the shape of the oxygen haemoglobin dissociation curve

Answer 18

Sigmoid curve

Question 19

what is the shape of the myoglobin dissociation curve

Answer 19

hyperbolic

Question 20

what is the Bohr effect

Answer 20

a shift of the sigmoid curve to the right

Question 21

what is the Haldane effect

Answer 21

Removing oxygen from Hb increases the ability of Hb to pick-up carbon dioxide and carbon dioxide generated H+

Question 22

what does the Bohr effect and the haldane effect work in synchrony to achieve

Answer 22

O2 liberation and uptake of CO2 & CO2 generated H+ at tissues

Question 23

what is the ideal O2 stats for COPD patients

Answer 23

88-92%

Question 24

what is the ideal O2 stats for patients

Answer 24

94-98%

Question 25

what is the ideal O2 stats for patients

Answer 25

94-98%

Question 26

how is oxygen transported in the blood

Answer 26

majority - bound to haemoglobin

small amount - in solution