EQUILIBRE ACIDE BASE

Question 1

What is the pH formula?

Answer 1

pH = Log1/H+

This formula defines the relationship between pH and hydrogen ion concentration.

Question 2

What are the survival limits of pH in the internal environment?

Answer 2

Between 6.9 and 7.9

Outside this range, severe physiological disturbances can occur.

Question 3

True or False: Alcalosis is as dangerous as acidosis.

Answer 3

True

Both conditions can lead to serious health issues.

Question 4

What is the normal pH level in the human body?

Answer 4

Around 7.4

This corresponds to approximately 40 mEq/L of hydrogen ions.

Question 5

What is the pH of pure water?

Answer 5

7.0

This is considered neutral on the pH scale.

Question 6

Why is pH control important?

Answer 6

• Stability of proteins and enzymes
• Stability of neuronal excitability
• Stability of ion exchanges (e.g., K+ and H+)

Maintaining pH is crucial for biological functions.

Question 7

How does the body fight against H+ ions?

Answer 7

The organism constantly combats H+ ions

This is essential to maintain acid-base balance.

Question 8

What causes the production of volatile acid in the body?

Answer 8

• Muscle activity
• Oxygen utilization
• Diet and intermediate metabolism

This leads to the production of 50 to 100 mEq of H+ ions per day.

Question 9

What is a buffer system?

Answer 9

A system that limits variation in pH due to H+ ion addition

Buffers play a critical role in maintaining pH stability.

Question 10

What is the formula for pH involving pKa?

Answer 10

pH = pKa + Log(base conjugate/acid conjugate)

This relationship is part of acid-base chemistry.

Question 11

Where are buffer systems present in the body?

Answer 11

• Intracellular
• In bones
• Extracellular

Each location has different efficacy and speed.

Question 12

What is the role of bicarbonate in pH regulation?

Answer 12

Combines with H+ ions to maintain pH

The reaction is HCO3- + H+ → H2CO3 → H2O + CO2.

Question 13

What is the primary role of the kidneys in long-term pH regulation?

Answer 13

• Reabsorption of bicarbonates
• Elimination of ammonium (NH4+)
• Excretion of H+

The kidneys are crucial for maintaining acid-base balance.

Question 14

Where does bicarbonate reabsorption occur in the kidneys?

Answer 14

• 80% in the proximal tubule
• 15% in the distal tubule
• 5% in the collecting duct

This distribution is important for effective pH regulation.

Question 15

What is the starting point for ammonium elimination in the kidneys?

Answer 15

Glutamine

Glutamine metabolism is essential for ammonia production.

Question 16

What happens to pH when the partial pressure of CO2 increases?

Answer 16

pH decreases

This inverse relationship is fundamental in respiratory physiology.

Question 17

What is the standard concentration of chloride and bicarbonate in the body?

Answer 17

• Chloride: 100 mmol/l
• Bicarbonate: 25 mmol/l

These values are essential for maintaining osmotic balance.

Question 18

What is the pH of interstitial fluid?

Answer 18

5.5

This pH is important for the balance between anions and cations.