Physiology

Question 1

Lung receptors

Answer 1

Stretch - prevent overinflation; juxtapulmonary - apnoea/shallow breathing in fluid overload; irritant - present throughout airways, cause cough/tachypnoea

Question 2

MAP

Answer 2

Approximately calculated as diastolic + 1/3(pulse pressure)

Question 3

Pulse pressure

Answer 3

Difference between systolic and diastolic blood pressure

Question 4

Myocyte action potential

Answer 4

Resting -90, threshold -65 - rapid influx of Na+ causes depolarisation to 30, K channels open - back down to 0, maintained at 0 by Ca influx (balances K efflux) then Ca closes and K efflux continues to return to resting (-90)