respiration

Question 1

what is meant by ‘partial pressure’?

Answer 1

the pressure exerted by a particular gas in a mixture of gases

Question 2

what is the respiration quotient?

Answer 2

RQ= volume of CO2 produced/volume of oxygen consumed

Question 3

outline the events of inspiration/inhalation

Answer 3

1) diaphragm contracts and moves down
2) chest expands, ribcage moves up and thoracic cavity is enlarged
3) pressure in the lungs decreases and air fills them

Question 4

outline the events of expiration/exhalation

Answer 4

1) diaphragm relaxes and moves up
2) chest expands and ribcage moves down
3) thoracic volume restored by elastic recoil of the diaphragm

Question 5

what is the relationship between airway resistance and lung volume?

Answer 5

inversely proportional

Question 6

is asthma an obstructive or restrictive deficit?

Answer 6

obstructive

Question 7

is pneumothorax an obstructive or restrictive deficit?

Answer 7

restrictive

Question 8

explain what happens during an asthma attack

Answer 8

increase in airway resistance as bronchial smooth muscle contracts

Question 9

what is meant by surface tension?

Answer 9

the pressure exerted on the alveoli to make them collapse

Question 10

what is FVC?

Answer 10

total volume of air that can be breathed out with max effort in one breath

Question 11

what is FEV?

Answer 11

how much air is breathed out in the first second

Question 12

how can FEV and FVC be used in diagnosis?

Answer 12

obstructive deficits: FEV/FVC = <7, FEV <80%

restrictive deficits: FEV/FVC = normal, FEV <80%

Question 13

what do pulmonary ARTERIES carry?

Answer 13

deoxygenated blood to right atrium

Question 14

what do pulmonary VEINS carry?

Answer 14

oxygenated blood to the left atrium

Question 15

what does p50 represent?

Answer 15

when Hb is 50% saturated/venous pO2 in exercise

Question 16

which conditions cause affinity of Hb for oxygen to increase?

Answer 16

high pH
decrease in temp
decrease in pCO2

Question 17

what does the Bohr effect refer to?

Answer 17

the effects of low pH and high pCO2 in causing a decrease in affinity of Hb for O2, resulting in release of O2 into oxygen poor tissues

Question 18

what is the pO2 and pCO2 in the pulmonary veins/systemic arteries?

Answer 18

pO2 100 mmHg

pCO2 40 mmHg

Question 19

what is the pO2 and pCO2 in the pulmonary arteries/systemic veins?

Answer 19

pO2 40mmHg

pCO2 46 mmHg

Question 20

by which methods is CO2 transported?

Answer 20

8% in plasma
80% carried as bicarbonate via carbonic anhydrase
12% binds to carbamino compounds such as Hb

Question 21

where is CO2 transported after it leaves the cell?

Answer 21

right atrium via systemic veins, then to alveoli by pulmonary arteries

Question 22

which nerve controls inspiration?

Answer 22

phrenic nerve; provides nerve supply to the diaphragm

Question 23

where are the respiratory receptors responsible for the control of rate and depth located?

Answer 23

brainstem and medulla

Question 24

name the effects of high altitude

Answer 24

pO2 decreases
Hb less saturated
tissues receive less O2
respiration cannot provide sufficient ATP
increase in cardiac output and ventilation

Question 25

name some adaptations to high altitude

Answer 25

increase in RBC number
increased vascularisation of the muscle
increase in concentration of myoglobin
greater number of mitochondria per muscle cell