PH ******

Question 1

Acidosis (respiratory)

Answer 1

RESPIRATORY: if pH drops due to respiratory dysfunction it is called respiratory acidosis.

- Rate of CO2 production exceeds rate of elimination 
- If CO2 accumulates reaction is driven to the right results in increased H+

Response: 
- Rise in PCO2 detected by chemoreceptors 
- Pons and medulla react by sending motor signal to respiratory muscles  RR rate and depth increase to "blow off" CO2

Question 2

Acidosis (metabolic)

Answer 2

2. METABOLIC: if pH drops due to non-respiratory cause it is called metabolic acidosis, acids accumulate in the blood due to cellular metabolism
   
   • Anaerobic cellular respiration (no O2) produces Latic acid
   • Large scale fat metabolism produces ketones
   • Excess alcohol metabolism produces acetic acid
   • Reaction is driven to the right

Responses:
Buffer system: Acts quickly, HCO3- binds excess H+ to increase pH other buffer systems act similarly
Respiratory system: Acts quickly, Blows off excess CO2 to increase pH
Renal system: Acts slowly, eliminates H+ from the body (along with other acids) to increase pH

Question 3

Consequences of acidosis

Answer 3

Consequences of acidosis:
- Weakness
- Headaches
- Confusion
- Vital sign changes

Question 4

Alkalosis (respiratory)

Answer 4

RESPIRATORY: if pH rises due to hyperventilation it is called respiratory alkalosis
- Rate of CO2 elimination exceeds rate of production
- If CO2 drops reaction is driven to the left
- Results in decreased H+

Response:
- Drop in PCO2 detected by chemoreceptors
- Pons and medulla react by inhibiting motor signals to respiratory muscles
RR rate and depth decrease to conserve CO2

Question 5

Alkalosis (metabolic)

Answer 5

METABOLIC: if pH rises due to a non-respiratory cause it is called metabolic alkalosis, occurs when non-respiratory acids are lost
- Can happen with loss of stomach acids (hydrochloric acid) with severe vomiting or loss of gastric contents through nasogastric drainage
- Use of diuretics causing excessive loss of H+

Responses:
Buffer system - acts quickly, HCO-3 releases H+ to decrease pH other buffer systems act similarly
Respiratory system - Acts quickly, reduces RR and depth to conserve CO2 to decrease pH
Renal system- acts slowly, reabsorbs H+ from the tubule into blood (along with other acids) to decrease pH.

Question 6

Consequences of alkalosis

Answer 6

• Confusion
• Cardiac arrhythmias
• Hyperreflexia
• Convulsions

Question 7

3 main buffer systems

Answer 7

• Proteins
• Carbonic acid - bicarbonate
  -Phosphates

Question 8

Buffer systems

Answer 8

Buffer systems - buffer systems in the blood respond immediately (HCO3-)

Buffer systems:
- Acts quickly
- Binds excess H+ to increase pH or release H+ to decrease pH
-Do not remove H+ from the body

Question 9

Describe the mechanisms used by the body to maintain pH homeostasis:

Answer 9

1. Buffer systems - buffer systems in the blood respond immediately (HCO3-)
   - Acts quickly
   - Binds excess H+ to increase pH or release H+ to decrease pH
   - Do not remove H+ from the body
2. Respiratory control of CO2 levels - respiratory response systems involving exhalation of CO2 take minutes to respond
   - Increasing rate and depth of breathing increases exhalation of CO2 to increase pH
   - Less Co2 available to form carbonic acid (H2CO3) therefore less H+ in the blood
3. Renal excretion/conservation of H+ & HCO3- ions - renal response systems involving kidney excretion of H+ take hours to respond (24hrs)
   - Acts slowly eliminates H+ from the body to increase pH
   - OR
   Conserves H+ from filtrate to decrease pH

Question 10

Respiratory system

Answer 10

• Increasing rate and depth of breathing increases exhalation of CO2 to increase pH
• Less Co2 available to form carbonic acid (H2CO3) therefore less H+ in the blood

Question 11

Renal excretion/conservation of H+ and HCO- ions.

Answer 11

• Acts slowly eliminates H+ from the body to increase pH
  
  • OR
  • Conserves H+ from filtrate to decrease pH