Question

1) State and explain common causes of metabolic acidosis

2) State and explain common causes of metabolic alkalosis.

3) Explain how carbon dioxide is eliminated in the lungs (a diagram is appropriate)

4) What are the major chemical buffer systems in the blood and in urine?

Answer 1

1) The common causes of metabolic acidosis are--

a)Diabetic ketoacidosis

b)Starvation ketoacidosis - In both a and b , there is increased ketone production because of either decreased blood glucose or inability of body to utilise glucose

c)Chronic diarrhea - Leads to bicarbonate loss and hence acidosis

d)Aspirin poisoning -It is acetylsalicylic acid.hence leads to metabolic acidosis.

2)a)Prolonged vomiting -Leads to hydrochloric acid loss

b)Hypokalemia -In this case , alkalosis occurs to maintain blood potassium level .

c)Diuresis -Can directly cause loss of H+ or indirectly by causing hypokalemia.

3)

Carbon dioxide is carried to lung by veins, partly dissolved in plasma and partly as carbaminohemoglobin.In lungs PCO2 is less and PO2 is more.Hence CO2 diffuses from capillary to alveoli and oxygen diffuses in the reverse direction.The CO2 in the alveoli is then expired.

4) The major chemical buffer systems are

a)Bicarbonate buffer system

b)Phosphate buffer system

c)Plasma protein buffer system