Lecture 17 Flashcards
Acid-Base Balance: a state in which the ______ of the body fluids is homeostatically regulated within this range (_____ to _____)
- __________: condition where characterized by an excess of acid in the body, leading to a _______ pH level
- ________: condition marked by an excess of alkali or base in the body, resulting to a ________ pH level
pH; 7.35-7.45
- acidosis; lower
- alkalosis; higher
_________ acid: those acids produced in the body from __________
- ex: __________ _____
volatile; carbon dioxide (CO2)
- carbonic acid
__________(_____) acids: acids that ______ be expelled as gases through respiratory means, but instead need to be eliminated through _____; all are produced from anything other than _____
- examples:
-_________ _____ (anaerobic fermentation)
-_________ _____ (nucleic acid catabolism)
- _________ and ________ (fat catabolism)
non-volatile (fixed); CANNOT; urine; CO2
- lactic acid
- phosphoric acids
- fatty acids; ketones
how is blood pH kept within a narrow range when our bodies are constantly producing acid? ________ ________
types:
1.
2.
Buffer Systems
1. Chemical
2. Physiological
The initial, secondary, and tertiary buffering systems
1st: ___________ (takes ______)
2nd: ____________ (takes ___to_____)
3rd: ____________ (takes _____ to _______) the body’s most potent acid-base regulatory system
1st: chemical buffers (seconds)
2nd: Respiratory system (min to hours)
3rd: Urinary system (days to weeks)
What two organ systems play an essential role in maintaining acid-base balance? (physiological buffers)
1.
2.
- Respiratory system (lungs)
- Urinary system (kidneys)
Chemical buffer: single or pairs sets (a weak acid and its salt) of molecules that act rapid to resist excessive shifts in pH by _______ or ______ _____
Three main chemical buffer systems in the body
1. ____________: important in _____
- ____________: very effective buffer in _____ and in _____
- ____________: important in _____ and _____
releasing; binding; H+
1. Bicarbonate buffer system; ECF
2. Phosphate buffer system; urine; ICF
3. Protein buffer system; ECF; ICF
Chemical buffers role in regulating blood pH is ______ because they DON’T _______ or ____ H+ to the body
- they provide only a ________ and ________ relief by quickly biding or realizing H+
- prolonged or severe disturbances in pH require _______ and ______ adjustments
LIMITED; eliminate; add
- immediate; temporary
- respiratory; renal
- Bicarbonate buffer system is more critical in ______
- Phosphate buffer system is more critical in _____ (also in ______)
- ECF
- ICF; urine
- If the pH of a solution decreases, the concentration of H+ in the solution ________
- If the pH of a solution increases, the concentration of H+ in the solution ________
- pH is a measure of the acidity or basicity of a solution and is defined as the _______ ______ (base 10) of the ____ ion concentration in the solution
-bases _____ H+
-acids _____ H+
- increases
- decreases
- negative logarithm; hydrogen
-accept
-donate
- Which group in a protein act as an acid? ________
because it can ______ H+ - Which group in a protein act as a base? _______
because it can ______ H+
- carboxyl group; release
- amino group; accept
When the body experiences alkalosis, how do proteins help restore the acid-base balance?
- alkalosis= _______ pH, ______ H+
- the ________ group (acting as an _____) can ______ H+…. therefore ________ the pH to normal ranges
- high; low
- carboxyl; acid; donate; lowering
When the body experiences acidosis, how do proteins help restore the acid-base balance?
- acidosis= _________ pH, _______ H+
- the ________ group (acting as a _____) can ______ H+… therefore ______ the pH to normal ranges
- low; high
- amino; base; accept; increasing
- Chemical formula for carbonic acid=
- Chemical formula for bicarbonate ion=
- H2CO3
- HCO3-
equation for the bicarbonate carbonic acid buffering system
CO2 + H2O –> H2CO3 (carbonic acid) –> HCO3- (bicarbonate base) + H+
- carbonic acid (H2CO3) is formed in our body through the combination of ________ with ________ in a _________ reaction
- this reaction is catalyze by the enzyme ______ __________, which is present in various tissues, including _______
- in equilibrium, carbon acid is in balance with __________ and this equilibrium is essential for maintaining the acid-base balance in the body
- carbon dioxide; water; reversible
- carbonic anhydrase; RBCs
- carbon dioxide
why is it essential to eliminate CO2?
because it helps regulate the acid-base balance in the body
- Which component acts as an acid (=H+ donor) in the carbonic acid-bicarbonate buffer system? __________
- Which component acts as a base (=H+ acceptor)? ________
- carbonic acid
- bicarbonate
Suppose there is an excess of acid (H+) in the blood (=acidosis or acidemia), and the _________ ion accepts those extra H+ of the solution…
- this would lead the pH to __________, because the ion is reducing the free H+
bicarbonate
- increase
Suppose there is a deficiency of acid (H+) or excess of a base in the blood (=alkalosis or alkalemia), and the ___________ donates H+ to the solution (releases the H+)…
- this would lead the pH to ________, because more H+ are being released into the blood
carbonic acid; decrease
- what is the way the body get rid of volatile acid? _________
- what is the way the body gets rid of fixed acid?
________ - can the respiratory get rid of increase fixed acids in blood? __________
- respiratory system (eliminate CO2 breathing)
- Through the urine (urinary system)
- NO, only volatile acids
- the organ that maintains bicarbonate levels in blood= __________
- the organ that maintains CO2 levels in blood= ________
- kidneys
- lungs
Hyperventilation (_______ in respiratory rate) causes an _________ in removal of CO2
- As CO2 combines with water to form ________ ____ (H2CO3) by expelling more CO2, the concentration of carbonic acid ________, shifting the equation to the _____
- ________ in H2CO3 leads to a ________ in H+ concentration
- __________ CO2 and H+ levels contribute to the ________ of pH (=_________)
increase; increase
- carbonic acid; decreases; LEFT
- decrease; decrease
- decreased; increase (=respiratory alkalosis)
A decrease in breathing rate causes a ________ in the removal of CO2
- we retain more CO2 in the body and more ________ will be formed, shifting the equation to the _________, which leads to ________ in H+
- _________ CO2 and H+ levels contribute to the ________ in pH (=____________)
decrease
- H2CO3 (carbonic acid); RIGHT; increase
- increased; decrease (=respiratory acidosis)
Reabsorption of bicarbonate in the renal tubule is always tied to the secretion of _____
H+
The goal of reabsorbing H+ from the urine is to counteract ___________
alkalosis (low H+ in blood)
The goal of reabsorbing more bicarbonate ions form the urine is to counteract ___________
acidosis
- goal of secreting more H+ in the urine is to counteract ________ (here is will bind to buffers such as bicarbonate, phosphate, or ammonia to neutralize it in order not to damage the tubules)
- goal of secreting bicarbonate ions in the urine is to counteract ________
- acidosis
- alkalosis
Three transport proteins of the renal tubule that are related to acid-base regulation
1. ________: located in PCT
2. ________: located in alpha-intercalated cells (in CD)
3. ________: located in alpha-intercalated cells (in CD)
- Na+/H+ exchanger
- K+/H+ ATPase
- H+ ATPase
In order to reabsorb bicarbonate ions from the lumen of the renal tubule, it must be decomposed to water and CO2 because…
- the renal tubules are _______ of reabsorbing HCO3- directly (not ________ to it) so they must transform it to CO2
- incapable; permeable
H+ is secreted into the renal tubule coming from the ____________ of ________ inside the renal tubular cell
decomposition; H2CO3 (carbonic acids)
4 steps for reabsorption of HCO3- (and H+ secretion) in the PCT
1. the ________ _______ or exchanger, exchanges ____ (is being reabsorbed) by ____. Almost all ___ secreted into tubular lumen bind to _______
- ____________ decomposes H2CO3 to H2O and CO2
- ________ enters the tubular cell and react with water forming _________ inside the cell
- ____________ is decomposed into H+ (which is secreted into the lumen) and ________ (which is recovered to the ______)
- Na+/H+ antiporter; Na+; H+; H+; HCO3-
- Carbonic anhydrase
- CO2; H2CO3
- H2CO3; HCO3-; plasma
- What metabolic changes would you check to see for acid-base balance? the concentration of ___________ ion in the blood
- What respiratory changes would you look for to see for acid-base balance disruption? changes in ______
- bicarbonate (H2CO3-)
- PCO2
- What acid-base disorder occurs with an elevated PCO2? ____________
- what acid-base disorder occurs with a decreased PCO2? ____________
- respiratory acidosis
- respiratory alkalosis
- Which acid-base disorder arises with an elevated HCO3-? __________
- Which acid-base disorder develops when there is a decreased HCO3-? ___________
- metabolic alkalosis
- metallic acidosis
What are two ways that metabolic acidosis can occur?
1.
2.
What are two ways that metabolic alkalosis can occur?
1.
2.
- loss of HCO3-
- ## Gain of acids (H+)1.Excess of HCO3-
- Loss of acids (H+)
Which organ system(s) compensates for acid-base disorders, whether of metabolic or respiratory origin?
- __________ compensations involve changes in respiratory rate and depth -> attempts to compensate for ________ acid-base imbalances
- ________ compensations modify blood levels of HCO3- –> works to correct imbalances caused by _________ disorders
- respiratory; metabolic
- renal; respiratory
- how do the lungs compensate for metabolic alkalosis? _________ the respiratory rate and depth, leading to an _______ in CO2
- how do the lungs compensate for metabolic acidosis? _________ the respiratory rate and depth, facilitating the elimination of excess CO2 (_______ pCO2)
- decrease; increase
- increase; decrease
- how do the kidneys compensate for respiratory acidosis? by ______ the excretion of __________ ions in the urine
- how do the kidneys compensate for respiratory alkalosis? by _________ excretion of __________ ions in the urine
- reducing; bicarbonate
- increasing; bicarbonate
Causes of..
- respiratory acidosis:
- metabolic acidosis:
- inhibition of respiratory center; lung damage; airway obstruction
- diarrhea, diabetic ketoacidosis, renal failure
Causes of…
- respiratory alkalosis:
- metabolic alkalosis:
- high altitude (decreased O2), anxiety
- overuse of antacids (e.g. bicarbonate), vomiting gastric contents
Respiratory disorders that cause…
- respiratory acidosis:
- respiratory alkalosis:
- lung damage, airway obsturction (decrease ventilation)
- anxiety, high altitude (increase hyperventilation)
Metabolic disorders that result in
- metabolic acidosis:
- metabolic alkalosis:
- renal failure (decrease acid elimination), diabetic ketoacidosis (increase acid production)
- vomiting gastric contents, overuse of antacids
