Acid-Base - Pt 1 Intro

Question 1

Bicarbonate levels in the blood are [].

Answer 1

24 mEg/L

Question 2

PaCo2 in arterial blood is []

Answer 2

40 mmHg

Question 3

[H+] in blood is []?

Answer 3

40 nEq/L

Question 4

Only the [] [] concentration contributes to pH. That which is bound to any [], chemical (proteins etc) oranything has [] contribution to the pH

Answer 4

Only the Free H+ concentration contributes to pH. That which is bound to any buffer, chemical (proteins etc) or anything has zero contribution to the pH

Question 5

A hydrogen ion (H+) is a single [] [] released from a hydrogen atom

Answer 5

free proton

Question 6

Easy definitions:

1. Acid = proton []
   
   1. [] [] is more likely to give up a proton. [] is a good example.
   2. [] [] is less likely to give up a proton. [] [] is a good example

Answer 6

1. Acid = proton donor
   
   1. Strong acid is more likely to give up a proton. HCl is a good example.
   2. Weak acid is less likely to give up a proton. Carbonic acid is a good example

Question 7

Extreme conditions of [H+]:

• 10 nEq/L….pH ~ []
• 160 nEq/L…pH ~[]

Answer 7

• 10 nEq/L….pH ~ 8
• 160 nEq/L…pH ~6.8

Question 8

pH is [] related to the [H+].

Answer 8

inversely

Question 9

• Normal pH of blood is [] +/- .02
• Acidosis occurs at a pH less than []
• Alkalosis occurs at a pH greater than []

Answer 9

• Normal pH of blood is 7.4 +/- .02
• Acidosis occurs at a pH less than 7.38
• Alkalosis occurs at a pH greater than 7.42

Question 10

• Volatile acids are defined as [] that may be eliminated by the [].
• Example: []

Answer 10

• Volatile acids are defined as gases that may be eliminated by the lungs.
• Example: CO2

Question 11

Fixed Acids:

• Acids which result from [] of sulfur or phosphate containg amino acids, phospholipids, nucleic acids, phosphoporteins and phosphoglycerides
• Primarily [] (H₂SO₄) and [] acid (H₃PO₄).

Answer 11

• Acids which result from metabolism of sulfur or phosphate containg amino acids, phospholipids, nucleic acids, phosphoporteins and phosphoglycerides
• Primarily sulfuric (H₂SO₄) and phosphoric acid (H₃PO₄).

Question 12

Organic Acids:

• Comes from ordinary [] such as lactic, pyruvic, ketones during oxygen [], shock, and []

Answer 12

Comes from ordinary production such as lactic, pyruvic, ketones during oxygen debt, shock, and exercise

Question 13

• There are 3 regulatory systems that interact to control body pH
  
  • [] buffering system
  • [] Responses
  • [] [] Responses

Answer 13

• There are 3 regulatory systems that interact to control body pH
  
  • Chemical buffering system
  • Respiratory Responses
  • Renal System Responses

Question 14

What are the 4 major physicoChemical Buffers?

Answer 14

Bicarbonate

Phosphate

Ammonia

Proteins

Question 15

The respiratory response will attempt to move pH back toward []but will always remain [], due to feedback [] and receptor [] and functionality.

Answer 15

The respiratory response will attempt to move pH back toward normal but will always remain incomplete, due to feedback inhibition and receptor sensitivity and functionality.

Question 16

Kidneys respond to pH via several mechanisms

1. Increased [] of H+/HCO3- into the urine
2. Increased [] of H+/HCO3- into the blood
3. [] [] H+ cellular secretory transport mechanisms
4. [] [] HCO3- cellular secretory transport mechanism
5. Make New []

Answer 16

1. Increased secretion of H+/HCO3- into the urine
2. Increased reabsorption of H+/HCO3- into the blood
3. Up/Down regulate H+ cellular secretory transport mechanisms
4. Up/Down regulate HCO3- cellular secretory transport mechanism
5. Make New HCO3-

Question 17

Normally, it doesn’t matter where the H+ comes from, it’ll always bind to [] if available.

Answer 17

bicarbonate

Question 18

1. pH and bicarbonate have a [] relationship. When [Bicarbonate] increases, pH []
2. pH and CO₂ have an [] relationship. When [CO₂ increases, pH []

Answer 18

1. pH and bicarbonate have a direct relationship. When [Bicarbonate] increases, pH increases
2. pH and CO₂ have an indirect relationship. When [bicarbonate] increases, pH decreases

Question 19

The optimum effect of a buffer occurs at the [] point of a titration curve. This is also the [] of the buffer - or its dissociation constant.

Answer 19

The optimum effect of a buffer occurs at the inflection point of a titration curve. This is also the pK of the buffer - or its dissociation constant.

Question 20

• Bicarbonate’s optimum pK is [] +/- 1 unit at a normal pH of 7.4
• However, this optimum pK falls under our normal body’s pH of 7.4, which is why bircarb is not the most [] buffer in our body.

Answer 20

• Bicarbonate’s optimum pK is 6.1 +/- 1 unit at a normal pH of 7.4
• However, this optimum pK falls under our normal body’s pH of 7.4, which is why bircarb is not the most powerful buffer in our body.

Question 21

Buffering Power is based on 2 things:

1. Buffering of a solution is [] when the pH of the solutin is at or near the [] of the buffer
   
   1. Or +/- one pH unit from the pK
2. [] of the buffering sibstances…The more buffer, the better

Answer 21

1. Buffering of a solution is greatest when the pH of the solution is at or near the pK of the buffer
   
   1. Or +/- one pH unit from the pK
2. Concentration of the buffering sibstances…The more buffer, the better

Question 22

1. The most important buffering system in the body is the [] [] []
2. This is becuase both elements are []systems.
   
   1. The lungs can [] CO2
   2. The kidneys can [] Bicarb/H+

Answer 22

1. The most important buffering system in the body is the Bicarbonate Buffer System
2. This is becuase both elements are open systems.
   
   1. The lungs can expire CO2
   2. The kidneys can micturate/save Bicarb/H+

Question 23

In normal body conditions, the bicarbonate buffering system cannot be [] to one extreme of the system or the other.

Answer 23

pushed

Question 24

The HCO3- buffering system links together [] buffering, the [] system and the [] system in the regulation of body pH

Answer 24

The HCO3- buffering system links together chemical buffering, the respiratory system and the renal system in the regulation of body pH

Question 25

Phosphate Buffer System:

• components are [] (dibasic phosphate) and [] (Monobasic phosphate)
• the pK is [] which is relatively close to body pH, so this system is more []than bicarbonate.
• However, [] levels are low so its not as important as bicarbonate

Answer 25

• components are HPO₄^2- (dibasic phosphate) and H₂PO₄^- (Monobasic phosphate)
• the pK is 6.8 which is relatively close to body pH, so this system is more powerful than bicarbonate.
• However, extracellular levels are low so its not as important as bicarbonate

Question 26

The phosphate buffering system is important in regulaitng [] pH.

Answer 26

Intracellular

Question 27

Phosphate buffering is very important withint the [] [] of the kidney.

Answer 27

Distal tubules

Question 28

The [] [] system is the most powerful buffer system of the body.

Answer 28

protein buffer

Question 29

The respiratory system regulates body pH by increasing or decreasing [] in the blood.

Answer 29

The respiratory system regulates body pH by increasing or decreasing [CO₂​] in the blood.

Question 30

Doubling ventilation [] the pH only slight, because it increases breathing ate which [] CO₂ in teh blood

Answer 30

Doubling ventilation increases the pH only slight, because it increases breathing rate which decreases CO₂​ in teh blood

Question 31

Halving the ventilation [] the pH only slightly by slowing respiration which causes an [] in CO₂ in the blood.

Answer 31

Halving the ventilation decreases the pH only slightly by slowing respiration which causes an increase in CO₂​ in the blood.

Question 32

[] sense changes in pH and via reflexes initiate correct changes in ventilation

Answer 32

Chemoreceptors

Question 33

The respiratory system effectiveness ranges from []%. It can never fully return pH to its normal levels.

Answer 33

50 - 75%

Question 34

The kidneys regulate pH primarily by increasing or decreasing [] in the body fluids

Answer 34

The kidneys regulate pH primarily by increasing or decreasing [HCO₃^-​] in the body fluids

Question 35

• Nonvolatile acids come primarily from the metabolism of [].
• Approximately [] mEq/day are formed

Answer 35

Proteins

80 mEq/L

Question 37

• The kidney filters roughly [] of bicarbonate.
• Also has to secrete [] of nonvolatile acids.
• So the total H+ load if []

Answer 37

• The kidney filters roughly 4320 mEq/day of bicarbonate.
• Also has to secrete 80 mEq/day of nonvolatile acids.
• So the total H+ load of 4400 mEq/day.

Question 38

What are the three fundamental mechanisms of homeostasis regulated by the the kidneys?

Answer 38

Secretion of H⁺

Reabsorption of HCO₃^-

Production of “New HCO₃^-

Question 39

• 80-90% of daily HCO₃^- reabsorption happens in the [] []
• 10% of daily HCO₃^- reabsorption happens in the [] [] []
• 5% of daily HCO₃^- reabsorption happens in the [] and []

Answer 39

• 80-90% of daily HCO₃^- reabsorption happens in the Proximal Tubule
• 10% of daily HCO₃^- reabsorption happens in the Thick ascending limb
• 5% of daily HCO₃^- reabsorption happens in the Distal Tubule and Collecting Duct

Question 40

• The [] [] is responsible for 85% of H+ secretion from the [] membrane of PCT cells
• T/F - this exchanger uses ATP
• This exchanger draws [] into the cell down its concentration gradient while secreting H+

Answer 40

• The NA+/H+ Exchanger is responsible for 85% of H+ secretion from the apical membrane
• FALSE - Secondary Active transport, so no ATP
• This exchanger draws sodium into the cell, down its concentration gradient while secreting H+

Question 41

10% of H+ secretion is performed by the [] on the [] membrane of PCT cells.

Answer 41

10% of H+ secretion is performed by the H+-ATPase on the apical membrane of PCT cells.

Question 42

Around the PCT, filtered [] combines with H+ to reform CO₂ and H₂O via [] [] [] carbonic anhydrase

Answer 42

Around the PCT, filtered HCO₃^- combines with H+ to reform CO₂ and H₂O via apical brush border carbonic anhydrase

Question 43

1. Cellular HCO₃^- transport across the basolateral membrane is facilitated by 2 transportes, what are they?
2. Are these transporters active transporters?

Answer 43

1. Transporters
   
   1. NBC1; Na⁺/HCO₃^-….Co-transporter
   2. AE1; Cl^-/HCO₃^-…..Anion exchanger
2. No, these are not active transporters.

Question 44

For every HCO₃^- reabsorbed a H⁺ is secreted in a [] ratio.

Answer 44

1:1