1
Q
(weak/strong acid or base)
- Reacts rapidly & strongly with Hydrogen to quickly remove H+ from solution
- Ex: OH- because it reacts strongly with hydrogen to form water
A
- Strong base
2
Q
The degree of disassociation of substances in water determines whether they are a __ __/__
A
The degree of disassociation of substances in water determines whether they are strong acid/base.
3
Q
a compound that produces hydroxyl ions in water
A
base
4
Q
- An __ is a compound that when it reacts with water gives off H+ ion.
- A ___is a compound that produces hydroxyl ion in water.
A
- An acid is a compound that when it reacts with water gives off H+ ion.
- A base is a compound that produces hydroxyl ion in water.
5
Q
A
6
Q
example of base that combines with H2O
A
- Bicarbonate (HCO3) because it can combine with water to form carbonic acid (H2CO3).
7
Q
- one of the most important body bases.
A
- Protein that are in hemoglobin in RBCs and some of the proteins found in other cells are one of the most important body bases.
8
Q
- Molecule formed by combination of 1 or more alkaline metals + OH- .
- Ex sodium(Na), Potassium (K), lithium (Li) etc. which can react with a high basic ion such as hydroxyl.
A
Alkali
9
Q
- Less likely to dissociate their ions; hydrogen is not released as quickly
- EX: H2CO3
A
- Weak acid
10
Q
- Binds with H+ more weakly
- Ex: HCO3-
A
- Weak base:
11
Q
- Rapidly dissociates & releases large amounts H+ in the solution
- Ex: HCL
A
- Strong acid
12
Q
formula for a normal pH
A
- pH = log 1/[H+] = −log[H+]
- Normal [H+] is 40 nEq/L (0.00000004Eq/L) or
- pH = − log[0.00000004]
- pH = 7.4
13
Q
- what is the range for urine pH
- depends on what?
A
- Urine pH range: 4.5-8.0
- Depends on acid-base status of ECF
- Kidneys play a major role in regulating the status.
14
Q
- Gastric pH
- secreted form what cells
- pH
- H+ conc compared to blood
A
- Gastric pH
- Example of an extremely acidic bodily fluid is hydrochloric acid (HCl) that is secreted from parietal cell of the stomach mucosa pH is 0.8 because of H+ concentration is 4 million times more than that found in the blood.
15
Q
3 Primary Systems Regulate H+ concentration
A
- 3 Primary Systems Regulate H+ concentration
- 1) Chemical acid-base buffer system
- Rapid (immediate)
- Buffer systems do not remove or add H+ but rather bind H+
- 2) Respiratory system
- Rapid (3-12 minutes)
- Removes CO2 in form of carbonic acid
- 3) Kidneys
- Slow (1-2 days)
- Eliminates excess acid or base
- Most powerful
- 1) Chemical acid-base buffer system
16
Q
where is carbonic acid abundant
A
- Enzyme is especially abundant in the walls of the alveoli where CO2 is released
- Also present in large amount in the epithelium cells of renal tubules where CO2 reacts with water to form carbonic acid
17
Q
•Bicarbonate Buffer System
2 parts
A
•Bicarbonate Buffer System
- Weak acid
- Bicarbonate salt
18
Q
- For any acid, concentration of acid relative to its dissociated ions is defined by ____ ____
A
- For any acid, concentration of acid relative to its dissociated ions is defined by the dissociation constant K’
19
Q
- CO2 dissolved in blood directly proportional to what?
A
- CO2 dissolved in blood directly proportional to amount of undissociated H2CO3
20
Q
A
21
Q
what is the henderson-hasselbalch equation/formula?
A
•Bicarbonate buffer system
- pH = pK + log [HCO3-/(0.03 x PCO2)]
- pH = 6.1 + log [HCO3-/(0.03 x PCO2)]
- pK is 6.1
- 0.03 is solubility coefficient for CO2
22
Q
Bicarbonate buffer system is the most important _____ intra/extra-cell buffer
A
Bicarbonate buffer system is the most important extracellular buffer
23
Q
there’s ___ x as much of the bicarbonate buffer system in the form of bicarbonate (HCO3-) as there is in the form of CO2
A
there’s 20 x as much of the bicarbonate buffer system in the form of bicarbonate (HCO3-) as there is in the form of CO2
24
Q
why is bicarb system, although most important, not expected to be powerful (2):
A
- 20 x as much HCO3 > CO2
- operates on the portion of the buffering curve where the slope is very low, and so that suggests that buffering power would be poor.
- Concentrations of CO2 & HCO3- not great
25
Speed/rate of buffering by plasma bicarbonate
* Buffering by plasma bicarbonate
* **Almost immediate**
26
below pH of 7.4, the hydrogen ion concentration increases ___ nano-equivalents per liter (nEq/L) for each ___ decrease in pH
* **below pH of 7.4**,
* the hydrogen ion concentration increases **1.25** nano-equivalents per liter (nEq/L) for each **0.01** decrease in pH
27
* above a pH 7.4, the hydrogen ion concentration will decrease at a rate of 0.8 nEq/L for each 0.01 increase in pH
* **above a pH 7.4**
* the hydrogen ion concentration will
* decrease at a rate of **0.8 nEq/**L for each **0.01** increase in pH
28
* When disturbances of acid-base result from primary change in extracellular fluid HCO3- concentration
* When disturbances of acid-base result from primary change in extracellular fluid HCO3- concentration is, that is referred to as a ***metabolic acid-base disorder***
29
* ***Respiratory acidosis – caused in \_\_\_***
* Acidosis caused by what primarily?
* ***Respiratory acidosis – caused in*** ↑ ***PCO2***
* Acidosis caused by a **primary increase in the partial pressure of carbon dioxide** is respiratory acidosis
30
***Respiratory alkalosis – caused by***
* ***Respiratory alkalosis – caused by*** ↓ ***PCO2***
* Alkalosis that is due to a **decrease in the partial pressure of carbon dioxide** is respiratory alkalosis
31
most important noncarbonic buffer in ECF
**Hgb**
32
* In RBC, HGB important buffer, it keeps the pH and Pk at what levels?
* In RBC, **HGB important buffer**
* it keeps the **pH 5.7-7.7**
* **(pKa 6.8)**
33
* Approximately \_\_\_\_% of the total buffering of body fluids is **intra/extra** cell and most of this is due to ___ \_\_\_\_
* Approximately **60-70%** of the total buffering of body fluids is **inside cells** and most of this is due to **intracellular proteins**
34
* compare Hg buffer system to bicarbonate buffering system
* In contrast to the bicarbonate buffer, hemoglobin is capable of buffering **both carbonic (CO2) & noncarbonic (nonvolatile) acid**s
35
* ____ mol/L dissolved CO2 in ECF
* corresponds to PCO2 of ___ mmHg
* **~ 1.2 mol/L dissolved CO2 in ECF**
* corresponds to **PCO2 of 40 mmHg**
36
* If the metabolic process is constant (metabolism not high or low), the only thing that will affect the level of the partial pressure of CO2 in ECF is the rate of ____ \_\_\_\_\_
* If the metabolic process is constant, the only thing that will affect the level of the partial pressure of CO2 in ECF is the rate of **alveolar ventilation.**
37
* how does H+ concentration affect the rate of alveolar ventilation
* and by what feedback mechanism
* H+ concentration affects rate of alveolar ventilation
* when the pH decreases, alveolar ventilation will increase to eliminate more carbon dioxide
* If pH rises, alveolar ventilation will decrease in order to reduce the amount of carbon dioxide eliminated.
* This process is a **NEGATIVE feedback mechanism**
38
* **If the pH of ECF is 7.4 with normal alveolar ventilation**
* **↑ alveolar ventilation** to **2x** normal **↑ pH** ~ \_\_\_- to about \_\_
* **↓ in alveolar ventilation** to **¼** normal **↓ pH** by \_\_- to \_\_
* **If the pH of ECF is 7.4 with normal alveolar ventilation**
* ↑ VA to 2x normal **↑ pH ~ 0.23- to about 7.63**
* ↓ VA to ¼ normal **↓ pH by 0.45- to 6.95**
39
* Normally the respiratory mechanism for controlling H+ ion concentration is **≈ \_\_\_\_\_% effective** which is a feedback mechanism of 1 to 3
* Normally the respiratory mechanism for controlling H+ ion concentration is **≈ 50-75% effective** which is a feedback mechanism of 1 to 3
40
* The respiratory regulation of the acid-base balance is a _____ type of buffer system
* It acts rapidly to control hydrogen ion concentration until the ___ can eliminate the imbalance
* Buffering power is ___ x as much acid or base as that of all the other chemical buffers in the body
* The respiratory regulation of the acid-base balance is a **physiological** type of buffer system
* It acts rapidly to control **hydrogen ion** concentration until the kidneys can eliminate the imbalance
* Buffering power is **1-2** x as much acid or base as that of all the other chemical buffers in the body
41
* Alveolar ventilation mediated by ____ in brainstem
* Respond to changes in CSF p\_\_\_
* MV ↑\_\_\_L/min for every acute ___ mmHg ↑ PaCO2
* For the most part, lungs eliminate approx. \_\_\_\_\_mEqs of CO2 per day as a byproduct of **\_\_\_\_** and \_\_\_metabolism
* Alveolar ventilation mediated by **chemoreceptors** in brainstem
* Respond to changes in CSF **pH**
* **MV ↑ 1-4L/min for every acute 1 mmHg ↑ PaCO2**
* For the most part, **lungs eliminate approx. 15 mEqs of CO2 per day** as a byproduct of **carbohydrate** and **fat** metabolism
42
* **Decreases in arterial blood pH** stimulate the **medullary** respiratory centers
* **Decreases in arterial blood pH** stimulate the **medullary** respiratory centers
43
* PaCO2 ↓\_\_\_ mmHg from 40 mmHg for every\_\_\_mEq/L ↓ plasma HCO3-
* PaCO2 **↓ 1-1.5 mmHg** from **40 mmHg** for **every 1 mEq/L ↓ plasma HCO3-**
44
* PaCO2 normally does not ↑ above ___ mmHg in compensation in response to metabolic alkalosis
* PaCO2 Can be expected to ↑\_\_\_ mmHg for each 1 mEq/L ↑ HCO3**-**
* PaCO2 normally does not ↑ above **55 mmHg** in compensation in response to metabolic alkalosis
* PaCO2 Can be expected to **↑ 0.25-1 mmHg for each 1 mEq/L ↑ HCO3-**
45
**Renal Control**
* Removes base from the blood by
**Renal Control**
* Kidneys control the acid-base balance by excreting either acidic or basic urine
* Mechanism:
* **Large amounts of HCO3- continuously filtered into tubules**
* Removes base from the blood
46
Renal Control
* Removes acid from the blood by
**Renal Control**
* **Large amounts of H+ secreted into tubular lumen by tubular epithelial cells**
* Removes acid from the blood
47
**Renal Control**
* More H+ lost than HCO3- → net loss of \_\_\_from extracellular fluid
* More HCO3- lost than H+ → net loss of \_\_\_
**Renal Control**
* **More H+ lost** than HCO3- → **net loss of acid** from extracellular fluid
* **More HCO3- lost** than H+ → **net loss of base**
48
Renal control
* Body produces ~\_\_\_ mEq of **nonvolatile acids each day** (cannot be excreted by lungs)
* Body produces **~ 80 mEq of nonvolatile acids** each day (cannot be excreted by lungs)
49
* Each day kidneys filter ~ ___ mEq HCO3-, most of which is reabsorbed by the \_\_\_\_
* Reabsorption of HCO3- & secretion of H+ are accomplished by process of\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
* **Each day kidneys filter ~ 4320 mEq HCO**3-, most of which is **reabsorbed by the tubules**
* Reabsorption of HCO3- & secretion of H+ are accomplished by process of **H+ secretion by the tubules**
50
* **This is the total H+ ions secreted into the tubules each day**
* **4400 H+ ions** secreted into the **tubules** each day
51
* The kidneys regulate ECF H+ concentration through 3 mechanisms:
* The kidneys regulate ECF H+ concentration through 3 mechanisms:
1. **Secretion of H+**
2. **Reabsorption of filtered HCO3-**
3. **Production of new HCO3-**
52
* H+ secretion & HCO3- reabsorption occur in renal tubules except the _____ and \_\_\_\_\_\_\_.
* H+ secretion & HCO3 - reabsorption occur in tubules **except** the **descending** and **ascending thin limbs of the loop of Henle**
53
* An acute change of PaCO2 by 10 mmHg is associated with change in pH of ___ units
* An **acute change of PaCO2** by **10 mmHg** is associated with change in pH of **0.08** units
54
* Metabolic acidosis should be referred to as ____ \_\_\_\_\_
* **Causes include:**
* **Metabolic acidosis** should be referred to as **nonrespiratory acidosis**
* **Does not always involve change in metabolism**
* Causes include:
* **ingestion of poison**
* infusion or production of a **fixed acid such as lactic acidosis**
* **decreased excretion of acid by the kidneys**
55
according to notes..
* An increase of PaCO2 with normal bicarb level is
according to notes..
* An increase of PaCO2 with normal bicarb level is ***uncompensated respiratory acidosis***
56
according to notes..
* Decrease in bicarb level when PaCO2 remains ~ 40 mmHg is **uncompensated metabolic acidosis**
57
* Combination of respiratory & metabolic acidosis is ***\_\_ \_\_***
* Combination of respiratory & metabolic acidosis is ***mixed acidosis***
* **Dramatic change in pH** with this situation
58
* Base change of 10 mEq/L is associated with pH change of ____ unit
* (in absence of change in PaCO2)
* **Base change of 10 mEq/L** is associated with pH change of **0.15 unit**
* **(in absence of change in PaCO2)**
59
can tubules reabsorb extra HCO3 in alkalosis
**negative**
urine will be basic
60
* Removing HCO3- by renal excretion has the same effect as what (relating to H)
* **Removing HCO3- by renal excretion** has the **same effect as adding H+ to ECF** and helps return the H+ concentration and pH back toward normal
61
* The kidneys can compensate for **respiratory acidosis and metabolic acidosis** of non-renal origin by: (2)
* **excreting fixed acid**
* **retaining HCO3- (Bicarb)**
62
* The kidneys can compensated for **respiratory alkalosis and metabolic alkalosis** of non-renal origin by:
* **Decreasing H+ ion excretion**
* **decreasing the retention of Bicarbonate**
63
* **Metabolic acidosis:**
* causes
* **Metabolic acidosis:**
* **Kidney failure**
* **diarrhea**
* **vomiting (intestinal contents)**
* **diabetes mellitus**
* **ingestion of certain poisons**
64
causes of metabolic alkalosis
* **Diuretics (except carbonic anhydrase inhibitors)**
* excess **aldosterone**
* ingestion of **alkaline drugs (antacids)**
* **vomiting (gastric contents)**
65
**Bicarb dose formula**
**and calculate for 70 kg, base deficit -10mEq/L**
**Bicarb dose:**
* **Base deficit x 30% x body weight in Kg**
* - 10 x 0.30 x 70 = **210 (absolute value)**
942
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