12 - Acid-base regulation

Question 1

Gove the typical values for PaO2 and PaCO2 in the post alveolar venules/systemic arterioles and the systemic veins/prealveolar arterioles

Answer 1

post alveolar venules/systemic arterioles

• PaO2 >10 kPa
• PaCO2 4.7-6.4 kPa

systemic veins/prealveolar arterioles

• PaO2 5.3 kPa
• PaCO2 6.1 kPa

Question 2

What is the difference between -osis and -aemia?

Answer 2

• osis describes events that are causing change

- aemia specifically describes the blood at a certain point in time

Question 3

What is alkalaemia?

Answer 3

refers to high-than-normal pH of the blood

Question 4

What is acidaemia?

Answer 4

refers to lower-than-normal pH of the blood

Question 5

What is alkalosis?

Answer 5

describes certain circumstances that will decrease [H+] and increase the pH

Question 6

What is acidosis?

Answer 6

describe circumstances that will increase [H+] and decrease pH

Question 7

What are the units of pH?

Answer 7

equivalence/litre (Eq/L)

Question 8

What re the 2 sources of acid? Give an example of each

Answer 8

• respiratory acid (majority)
  (from CO2)
  e.g. carbonic acid
• metabolic acid (less comes from here)
  e. g. lactic acid

Question 9

Give the equations for calculating pH and proton concentration

Answer 9

pH = log10[H+]

[H+] = 10^-pH

Question 10

What are the values of arterial and venous pH?

Answer 10

arterial = 7.4
venous = 7.36

Question 11

What is typical cardiac output?

Answer 11

5 L/min