EXAM III: 6A Respiratory Regulation of pH/ Disturbances

Question 0

What is the basic definition of Bases?

Answer 0

• Bases are H+ acceptors (Soak up H+)

- Similar to acids, bases can also be classified as strong or weak

Question 1

What is the basic definition of Acids?

Answer 1

• Acids are H+ donors (releases H+)
• Strong acids dissociate completely in solution
• Weak acids do not dissociate completely (reversible)

Question 2

What is pH?

Answer 2

Measure of H+ concentration

*pH= -log [H+]

-pH of ECF can also be measured by Hasselbach equation
pH=pka+log[HCO3-]/[CO2]

Question 3

What is the normal range of pH of the ECF?

Answer 3

7.35-7.45

• It is the ratio rather than the absolute values for bicarbonate and dissolved CO2 that determines pH
• Example when ratio is 20:1 pH is 7.4

Question 4

What is the concentration of H+ in healthy individuals?

Answer 4

50-100 mEq/L of H+ via Metabolic reactions.

Question 5

What are buffers?

Answer 5

• Substance that prevent changes in pH
• Done by binding H+ (act like bases)
• if pH drops they release H+ (act like acids)

Question 6

What are the 3 major chemical buffers in the body?

Answer 6

1) Carbonic acid (H2Co3)- Bicarbonate (HCO3-)
2) Phosphate
3) Protein (Hemoglobin and albumins)

Question 7

How does Carbonic acids and Bicarbonate regulate body?

Answer 7

• If excess H+ is present (acidosis) then the rxn favored to the left. H+ going to to be soaked up
• If shortage (alkalosis), then rxn is favored to the right. H+ is released.

Question 8

How does Phosphate regulate body?

Answer 8

• If excess H+ is present (Acidosis) then rxn is favored by right and H+ is soaked up
• If shortage, than rxn is favored to the left. H+ released

Question 9

How do Proteins regulate body?

Answer 9

• If excess H+ is present, the amine portion soaks up H+

- IF shortage H+, carbonyl portion releases H+

Question 10

How does Respiratory regulation control pH?

Answer 10

-Any increase in conc. of ECF CO2 lowers the pH

-A decrease in the rate and/or depth of breathing increases the retention of CO2 within body
Result–>increase in the amount of H2Co3 formed & consequently the amount of H+ formed

***Hypoventilation decreases the pH of the ECF

Question 11

How does a decrease in CO2 concentration raise the pH?

Answer 11

By decreasing the level of free H+

Question 12

What does an increase in the rate and /or depth of breathing do?

Answer 12

Increases the amount of CO2 exhaled, thereby reducing the CO2 level in the blood
Result–> reduces the amount of H2CO3 formed & consequently the amount of H+ formed

***Hyperventilation increases the pH of the ECF

Question 13

How do the respiratory centers in the brainstem help regulate the H+ concentration?

Answer 13

By controlling the rate & depth of breathing

Question 14

How do the kidneys regulate the pH?

Answer 14

1) Secreting H+
2) Reabsorbing HCO3
3) Synthesizing HCO3

Question 15

What does H+ secretion from the kidneys do?

Answer 15

1) causes the urine to become more acidic

2) occurs mainly in the distal convoluted tubule

Question 16

Where does reabsorbing HCO3- via the kidneys take place?

Answer 16

Occurs mainly in the proximal convoluted tubule

Question 17

Where does synthesis of HCO3- from the kidneys take place?

Answer 17

Mainly in the cells lining the proximal convoluted tubule

Question 18

What are the ABG (arterial blood gases) for Respiratory Acidosis?

Answer 18

• Decreased pH

- Elevated PCO2

Question 19

What are the causes of Respiratory Acidosis?

Answer 19

1) Emphysema
2) Pulmonary edema
3) Chronic bronchitis
4) Opioid overdose
5) Neuromuscular disease (myasthenia gravis, gulline-barre syndrome)
6) injury to brainstem

Question 20

What is the compensation for Respiratory Acidosis?

Answer 20

1) Buffers act like bases

2) Kidneys increase their secretion of H+, reabsorption of HCO3- & synthesis of HCO3-

Question 21

What are the ABG (arterial blood gases) for Respiratory Alkalosis?

Answer 21

1) Increased pH

2) Decreased PCO2

Question 22

What are the cause of Respiratory Alkalosis?

Answer 22

1) Breathing at higher altitudes
2) Anxiety/fear
3) Salicylic acid (Aspirin) overdose
4) Fever

Question 23

What is the compensation for Respiratory Alkalosis?

Answer 23

1) Buffers act like acids

2) Kidneys decrease their secretions of H+, reabsorption of HCO3- & synthesis of HCO3-

Question 24

What are the ABG (arterial blood gases) for Metabolic Acidosis?

Answer 24

1) Decreased pH

2) Decreased HCO3-

Question 25

What are the causes of Metabolic Acidosis?

Answer 25

1) Ketoacidosis: diabetes, alcoholism, fasting/starvation
2) Lactic acidosis
3) Ethylene glycol poisoning
4) Aspirin overdose (early poisoning)
5) Severe diarrhea
6) Proximal (type 2 ) renal tubular acidosis (proximal bicarboante reabsorption is impaired)

Question 26

What is the compensation of Metabolic Acidosis?

Answer 26

1) Buffers act like bases
2) Lungs undergo hyperventilation
3) Kidneys increase their secretion of H+ reabsorption of HCO3- & synthesis of HCO3-

Question 27

What are the ABG (arterial blood gases) for Metabolic Alkalosis?

Answer 27

1) increased pH

2) increased HCO3-

Question 28

What are the causes of Metabolic Alkalosis?

Answer 28

1) Severe emesis (vomiting)
2) Gastric suctioning
3) Renal H+ loss (very complex mech)

Question 29

What are the compensation for Metabolic Alkalosis?

Answer 29

1) Buffers act like acids
2) Lungs undergo hypoventilation
3) kidneys decrease secretion of H+, reabsorption of HCO3- & synthesis of HCO3-