Mixed flashcards (lectures 1-8)

Question 1

the lining of the respiratory tract is composed of what cell

Answer 1

pseudo-stratified ciliated columnar cells

Question 2

what is the major determinant of airway resistance

Answer 2

radii of the airways

Question 3

what does FRC stand for

Answer 3

functional residual capacity

Question 4

what is the functional residual capacity

Answer 4

expiratory reserve volume + residual volume

Question 5

what does the equation FEV1:FVC refer to

Answer 5

fraction of vital capacity expired in 1 second

Question 6

if pressure in the intraplueral space was positive what would happen to the lungs

Answer 6

the lungs would collapse

Question 7

why is the apex of the lung less compliant than the base

Answer 7

because the alveoli at the apex are more inflated at FRC therefore they aren’t completely empty when the next inhalation happens

Question 8

the base of the lung is more compliant than the apex why is this

Answer 8

the weight of the top of the lung and the diaphragm at the bottom of the lung base, compress the alveoli at the base on the lung and this makes it more compliant on inspiration

Question 9

what is the opposite of a shunt

Answer 9

alveoli dead space

Question 10

without haemoglobin how much oxygen dissolves per liter of plasma

Answer 10

3ml/L

Question 11

with the aid of haemoglobin how much oxygen dissolves per liter of plasma

Answer 11

200ml/L

Question 12

92% of Hb of redblood cells is what type of Hb

Answer 12

HbA

Question 13

8% of Hb of redblood cells is what type of Hb

Answer 13

HbA2

Question 14

during hyperventilation what does PaO2 rise to and PaCO2 fall to

Answer 14

around 120mmHg for O2

around 20mmHg for Co2

Question 15

during hypoventilation what does PaO2 fall to and PaCo2 rise to

Answer 15

PaO2 fall to around 30mmHg

PaCO2 rise to around 100mmHg

Question 16

what percent of oxygen in the blood is extracted by tissues at rest

Answer 16

25%

Question 17

at PaO2 of 60mmHg what percentage is haemoglobin saturated with oxygen

Answer 17

Hb is still 90% saturated at 60mmHg

Question 18

at normal venous PaO2 (around 40mmHg) what percentage is Hb saturated with oxygen

Answer 18

Hb is still 75% saturated with oxygen

Question 19

why does HbF have a higher affinity for oxygen than HbA

Answer 19

so it is able to extract oxygen from maternal arterial blood

Question 20

when Co2 diffuses from the tissue into the blood 7% of it does what

Answer 20

remains dissolved in plasma and erythrocytes

Question 21

when Co2 diffuses from the plasma to the blood 23% of it does what

Answer 21

combines in the erythrocytes with deoxyhemoglobin to form carbamino compounds

Question 22

when Co2 diffuses from the plasma to the blood 70% of it does what

Answer 22

% combines in the erythrocytes with water to form carbonic acid, which then dissociates to yield bicarbonate and H+ ions

Question 23

how is CO2 capable of changing ECF pH

Answer 23

CO2 + H2O ↔ H2CO3 ↔ HCO3 + H+

therfore H+ ions can affect the pH

Question 24

what affect does hypoventilation have on blood pH

Answer 24

leads to decrease in pH and respiratory acidosis

Question 25

what affect does hyperventilation have on pH

Answer 25

leads to increase in pH and respiratory alkalosis