breathing rate and homeostatis

Question 1

respiratory quotient

Answer 1

ratio of amount of CO2 produced by the body to the amount of oxygen consumed

Question 2

what can cause a decrease in RQ (avg normally 0.8)

Answer 2

excess fat intake or diabetes
starvation

Question 3

inspiratory muscles

Answer 3

diaphragm
external intercostals
accessory muscles:
scalene muscles
sternomastoids
muscles of neck

Question 4

muscles of expiration (forced)

Answer 4

rectus abdominus
internal and external obliques
internal intercostals

Question 5

dorsal respiratory group (DRG)

Answer 5

controls the diaphragm, involved in inspiration

Question 6

ventral respiratory group (VRG)

Answer 6

controls intercostals muscles, involved in inspiration and expiration

Question 7

apneustic centre

Answer 7

modulates DRG function to prevent over-expansion, loss of this area causes apneusis

Question 8

pneumotaxic centre

Answer 8

modulated DRG, increasing RR and decreasing VT (tidal vol) to maintain MV (mechanical ventilation)

Question 9

how is oxygen carried in the blood

Answer 9

bound to haemoglobin (97%)
dissolved in blood (3%)

Question 10

how is carbon dioxide carried in the blood

Answer 10

as bicarbonate (90%)
as dissolved CO2 (5%)
as carbamino (5%)

Question 11

what can testing A-a gradient be useful for

Answer 11

recognising shunts and give an idea of VQ mismatch

Question 12

lung compliance

Answer 12

vol change per unit pressure change (mls/cmH2O)

Question 13

hypoxemia causes

Answer 13

alveolar ventilation (V) and pulmonary perfusion (Q) mismatch
intrapulmonary shunt
hypoventilation

Question 14

main types of acid-base imbalance

Answer 14

respiratory acidosis
metabolic acidosis
metabolic alkalosis
respiratory alkalosis