blood gases and ventilation

Question 1

where are the respiratory centres located?

Answer 1

pons and medulla

Question 2

what is a normal respiratory rate?

Answer 2

12-18 breaths per minute

Question 3

what is normal body ph?

Answer 3

7.4

Question 4

what are the 3 methods of hydrogen ion buffering in the kidneys?

Answer 4

• bicarbonate buffering
• glutamate buffering
• phosphate buffering

Question 5

what are the 5 steps of the phosphate buffering system?

Answer 5

1) Na+ and HCO3- are filtered In the glomerulus
2) renal tubule cells secrete H+ into the tubule lumen in exchange for Na+ ions
3) H+ react with HCO3- in the lumen to form CO2 which then diffuses back into the tubule cell
4) HCO3- is reformed from CO2 in the renal tubule
5) Na+ and HCO3- are symported into the interstitial fluid so that HCO3- can be reused in the body, H+ is excreted in urine

Question 6

briefly explain the phosphate buffering system in the nephron of the kidneys?

Answer 6

HPO42- enters the renal tubule and combines with H+ to form H2PO4- which is excreted in urine

Question 7

give one cause of non respiratory acidosis?

Answer 7

diabetic ketoacidosis

Question 8

what causes diabetic ketoacidosis?

Answer 8

an absolute lack of insulin causes the metabolism of fatty acids which causes a build up of H+

Question 9

what can respiratory acidosis be caused by?

Answer 9

airway obstruction, depression of the respiratory centre