12: Physiology 8 Flashcards Preview

Renal Week 3 2017/18 > 12: Physiology 8 > Flashcards

Flashcards in 12: Physiology 8 Deck (43)
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1

What is the normal pH of the blood?

7.4

2

Which blood vessels have a lower pH?

Veins

more CO2

3

What is the normal blood concentration of bicarbonate ions?

22 - 28

sits around 25

4

What is the normal partial pressure of CO2 in the blood?

40 mmHg

5

What needs to be brought back to normal to

a) compensate for

b) correct

an acid-base imbalance?

a) pH

b) pH, [HCO3-], pCO2

6

What are compensation and correction of an acid-base disturbance?

Compensation - bringing pH back to normal

Correction - bringing pH, [HCO3-] and pCO2

7

What are the four types of acid-base imbalance?

Metabolic acidosis and alkalosis

Respiratory acidosis and alkalosis

8

What solutions are responsible for correcting short-term changes in pH?

Buffers

9

What component of blood acts as a buffer?

Hb

unoxygenated blood has a higher affinity for H+ than oxygenated blood

10

What happens when buffers run out?

Kidney replaces them

11

ph = pk + log(kidneys/lungs)

12

Which organs regulate blood concentration of

a) CO2

b) bicarbonate?

a) Lungs

b) Kidneys

13

What are the normal ranges of concs. for

a) pH

b) bicarbonate?

a) 7.35 - 7.45 (normal is 7.4)

b) 22 - 28 (normal is 25)

14

What general group of diseases causes CO2 retention?

Respiratory disease

15

CO2 retention causes an (increase / decrease) in the concentrations of which ions?

H+ (importantly)

HCO3-

shifts equilibrium to the right and causes acidosis

16

Can buffer solutions buffer themselves?

No

So an increase in CO2 causes both H+ and HCO3 to increase, but HCO3 doesn't compensate

17

When is respiratory acidosis

a) compensated

b) uncompensated?

a) High CO2, normal pH

b) High CO2, low pH

18

Which system compensates for respiratory acidosis?

Renal

19

What drives bicarbonate reabsorption by the kidneys?

H+ secretion by the kidneys

20

How much bicarbonate is reabsorbed by the kidneys in metabolic acidosis?

All of it

21

What happens to H+ ions after they are excreted into the renal tubules to drive HCO3- reabsorption?

Excreted in urine as titratable acid and ammonium

22

What increases as a result of renal compensation for metabolic acidosis?

[HCO3-] reabsorption

and therefore pH increase

23

After the kidneys have compensated for a metabolic acidosis, how do you correct it?

Restore normal ventilation

24

What are some causes of respiratory alkalosis?

High altitude (conc of oxygen breathed in decreases, rate of body's removal of CO2 stays the same --> alkalosis)

Hyperventilation

25

What is removed excessively in respiratory alkalosis?

CO2

26

What happens as a result of excessive CO2 removal in respiratory alkalosis?

H+ and HCO3- decrease

CO2 starts to increase

equilibrium shifts to the left

27

What system compensates for respiratory alkalosis?

Renal

28

What happens to H+ secretion in respiratory alkalosis?

Decreases, as no CO2 to drive it

29

What happens to bicarbonate reabsorption in metabolic alkalosis?

Decreases

As H+ isn't being secreted to drive it

30

In uncompensated respiratory alkalosis, the urine turns ___.

alkaline