The Respiratory System

Question 1

what are the zones of the respiratory system?

Answer 1

the conducting zone

the respiratory zone (gas exchange)

Question 2

how does ventilation occur?

Answer 2

decrease lung pressure- increase lung volume- air in

increase air pressure- decrease lung volume - air out

Question 3

what is boyles law?

Answer 3

the pressure of a quantity of gas is inversely proportional to its volume
P = 1/V

Question 4

what are the pleural membranes?

Answer 4

the parietal and visceral (outer)

Question 5

what is intrapleural pressure?

Answer 5

pleural membranes pulled in opposite directions - always lower than intra-alveolar pressure
keeps lungs adhered to thoracic cavity

Question 6

what is a pneumothorax?

Answer 6

collapsed lung

Question 7

what does alveoli fluid and air in alveoli generate?

Answer 7

surface tension

Question 8

what is the role of surfactant?

Answer 8

disrupts cohesive forces between water molecules and breaks surface tension

Question 9

what causes respiratory distress syndrome?

Answer 9

premature infants born without surfactant- difficulty in expanding lung volume

Question 10

what is surfactant composed of and where is it produced?

Answer 10

composed of lipoprotein complexes

produced by type II alveolar cells late in foetal development

Question 11

what triggers bronchodilation?

Answer 11

noradrenaline - sympathetic

Question 12

what triggers bronchoconstriction?

Answer 12

acetylcholine - parasympathetic

Question 13

how is asthma treated?

Answer 13

stimulation of B adrenergic receptors with adrenaline or P agonists triggers bronchodilation

Question 14

what is the pulmonary function test?

Answer 14

spirometry

Question 15

what is tidal volume?

Answer 15

vol of air inspired or expired during regular breathing

Question 16

what is the minute volume?

Answer 16

ventilation rate x tidal volume

Question 17

what is vital capacity?

Answer 17

tidal vol + ERV + IRV

Question 18

What is total lung capacity?

Answer 18

vital capacity + residual volume

Question 19

what does asthma affect?

Answer 19

rates of expiration and inspiration

Question 20

how are obstructive lung disorders diagnosed?

Answer 20

one second forced expiratory volume which measures percentage of vital capacity exhaled in 1 second

Question 21

what is partial pressure?

Answer 21

individual pressure of each gas

atm pressure x % of gas in atmosphere

Question 22

what does the ability of gas to dissolve in blood depend on?

ie Henrys Law

Answer 22

• pressure gradient
• solubility of gas
• temp of blood

Question 23

what is the diffusion of gases in the alveoli due to?

Answer 23

pressure gradient

Question 24

what causes decreased diffusion of oxygen?

Answer 24

emphysema and pulmonary oedema

Question 25

how is o2 transported in the blood?

Answer 25

dissolved in plasma and mostly bound to Hb

Question 26

what effects haemoglobin affinity to bind O2?

Answer 26

Po2 of plasma and total Hb levels

Question 27

what effects O2 affinity to Hb?

Answer 27

• blood pH
• blood temp
• metabolic activity

Question 28

how is CO2 transported?

Answer 28

• plasma
• Hb
• mostly converted to Bicarbonate in RBCs

Question 29

what enzyme converts CO2 to bicarbonate?

Answer 29

carbonic anhydrase