(P) Lec 4: Acid-Base Balance (Part 2) Flashcards
Blood Buffers
- A buffer in both plasma and cells
- Contains charges on their surface
Plasma Proteins
Plasma Proteins
What are the acidic and basic components?
Acidic: Carboxyl group (COOH)
Basic: Amino group
- Proteins are considered ____, meaning they can have either a positive or negative charge
- A negative charge makes them capable to bind with ____
- Amphoteric
- Hydrogen ions
Plasma Proteins
- In an acidic medium, the ____ act as a base as the amino group accepts hydrogen ions forming an ____ ion
- In an alkaline medium, ____ donates hydrogen ions
- Proteins; ammonium
- COOH
Plasma Proteins
The more this group is contained in histidine, the better the plasma proteins will be in acting as a buffer
Imidazole
Plasma Proteins
This protein accounts for the greatest buffer as it has 16 histidine residues
Albumin
Parameters of Interest
Refers to the negative logarithm of hydrogen ion activity with a formula of “-log[H]”
pH
Parameters of Interest: pH
What is the normal pH value range of the body?
7.35-7.45
Acidosis is less than 7.35 while alkalosis is more than 7.45
Parameters of Interest: pH
The optimum pH for arterial blood
7.40
Parameters of Interest: pH
The pH that represents the difference of arterial and venous blood because of the chloride isohydric shift
0.03 pH
Parameters of Interest: pH
What type of blood sample can be used to measure pH, pCO2, and HCO3?
Venous blood
Note: Applicable in cases of patients with fever
Parameters of Interest: pH
Venous blood can be used to measure pH, pCO2, and HCO3, except for what?
pO2 (partial pressure of oxygen)
Parameters of Interest: pH
The pH decreases by ____ per each Celsius above 37ºC
0.015
Parameters of Interest: pH
TOF: The lower the temperature, the lower the pH
False (inversely proportional)
Parameters of Interest: pH
Significance of the body pH
1. For proper (physiologic/anatomical) functioning of cells and tissues
2. Any change can alter (enzyme/hormone) activity
3. Nerve conduction and muscle (relaxation/contraction) are pH dependent
4. All (metabolic/catabolic) processes are pH dependent
5. The uptake, transport and (binding/release) of O2 and CO2 are pH dependent
- Physiologic
- Enzyme
- Contraction
- Metabolic
- Release
Parameters of Interest: Ventilation
What is the normal pCO2?
35-45 mmHg
Parameters of Interest: Ventilation
If pCO2 is < 35 mmHg and > 45 mmHg, what 2 conditions are related?
- < 35 mmHg - respiratory alkalosis
- > 45 mmHg - respiratory acidosis
Note: CO2 binds with water to form H2CO3, so an increase in CO2 means higher acidity
Parameters of Interest: Ventilation
This is the index of efficient gas exchange
pCO2
Parameters of Interest: Ventilation
Total CO2 values differ from arterial and venous whole blood, what are those value ranges?
- 19-24 mmol/L (WB arterial)
- 22-26 mmol/L (WB venous)
Parameters of Interest: Metabolic Process
To evaluate the ____, the parameter used is ____; the organ is the one responsible for the reclamation and excretion of said substance
- Kidneys
- Bicarbonate
Parameters of Interest: Metabolic Process
What is the normal HCO3 level?
21-28 mEq/L
Parameters of Interest: Metabolic Process
If HCO3 is < 21 mEq/L and > 28 mEq/L, what 2 conditions are related?
- < 21 mEq/L - metabolic acidosis
- > 28 mEq/L - metabolic alkalosis
Parameters of Interest: Metabolic Process
____ is the basic component while ____ is the acidic component of this buffer system
- Bicarbonate
- Carbonic Acid
Parameters of Interest: Metabolic Process
It is refered to as “metabolic” because it is being regulated by the kidneys but it can also be called as ____ acidosis/alkalosis
Non-respiratory
Note: “Metabolic” refers to its relation to bicarbonates