Acid-Base Balance Flashcards
The greatest percentage of the body’s water is in
the intracellular fluid
Hypertension is likely to increase the secretion of
atrial natriuretic peptide
______ increases water reabsorption without increasing sodium reabsorption.
Antidiuretic hormone
Hypotonic hydration can result from
ADH hypersecretion
Tetanus is most likely a result from
hypocalcemia
The principle determinant of intracellular osmolarity and cellular volume is
potassium
Increased excretion of ammonium chloride in the urine most likely indicates
hypercalcemia
The most effective buffer in the intracellular fluid is
protein
Tubular secretion of hydrogen is directly linked to
tubular reabsorption of sodium
The most abundant cation in the ECF is
Na+
The most abundant cation in the ICF is
K+
The skin loses water by two processes, sweating and ____
cutaneous transport
Water produced by the body’s chemical reactions is called _____
metabolic water
An excessive concentration of potassium ions in the blood is called _____
hyperkalemia
A deficiency of sodium ions in the blood is called ______
hyponatremia
A blood pH of 7.2 caused by inadequate pulmonary ventilation would be classified as _____
respiratory acidosis
Long-term satiation of thirst depends on a reduction of the _____ of the blood.
osmolarity
The 3 types of homeostatic balance
water balance
electrolyte balance (electrolytes absorbed in SI balance that lost in urine)
acid-base balance (body rids itself of acid/H+ at rate that balances metabolic production)
Bodily water gains come from these 2 sources
Preformed water (2,300 mL/day) from ingested food and drink (1600 mL/day) metabolic water (200 mL/day) as a by-product of aerobic metabolism and dehydration synthesis
The major fluid compartments of the body
65% intracellular fluid (ICF)
35% extracellular fluid (ECF)
Water moves by _____ from one fluid compartment to another, and is determined by the relative _____ of solutes in each compartment. _____ are the most abundant solutes particles and play the principle role in governing the body’s water distribution and total water content.
osmosis, concentrations, electrolytes
In edema, fluid accumulates within the _____ compartments. It is associated with diseases of the heart, liver and kidneys and is a form of _____-retention imbalance.
Interstitial, salt
Dehydration reduces blood volume and blood pressure and increases blood _____.
osmolarity
The rise in the osmolarity of the _____ is associated with the drop in blood volume. When blood pressure drops, the _____ produces an antidiuretic hormone to promote water conservation. The _____ _____ _____ system becomes activated, and the _____ produces a conscious sense of thirst.
ECF, hypothalamus, renin-angiotensin-aldosterone, cortex
_____ secretion is stimulated by hypothalamic osmoreceptors in response to dehydration. This gives rise to a decrease in water volume and increased osmolarity, which concentrates _____. _____ release is inhibited when blood volume and blood pressure is too high or blood osmolarity is too low. This is an effective way to compensate for _____.
ADH, urine, ADH, hypertension
Fluid imbalance refers to these 3 kinds of abnormalities
- Total volume
- concentration
- distribution of fluid among the compartments
2 main factors in fluid deficiency
hypovolemia (volume depletion)
dehydration (negative water balance)
In hypovolemia, total body _____ declines, but _____ remains normal. Can occur from hemorrage, severe burns, chronic vomiting, or diarrhea.
water, osmolarity
In dehydration, the body eliminates significantly more _____ than _____. The total body _____ declines, and _____ rises. It can result from insufficient water intake, diabetes, ADH hyposecretion (diabetes insipidus), profuse sweating, or overuse of diuretics. Infants are more volunerable to dehydration due to high _____ rate that demands high urine excretion.
water, sodium, water, osmolarity, metabolic
The body conserves heat by _____ blood vessels of the skin and forcing blood to deeper circulation. This raises blood pressure which inhibits the secretion of _____. It also increases secretion of _____ _____ _____. Urine output is _____ and blood volume _____.
constricting, ADH, atrial natriuretic peptide, increased, reduced
Cold air is drier and increases _____ water loss, also reducing blood volume. Cold weather respiratory and urinary water losses cause a state of _____.
respiratory, hypovolemia
Exercise dilates vessels in _____ muscles. Insufficient blood for the rest of the body can bring on weakness, fatigue, or fainting (_____ shock)
skeletal, hypovolemic
In excessive sweating, the blood absorbs tissue fluid (300 mL) to replace volume loss. Tissue fluid is pulled from _____ (700 mL).
ICF
dehydration, excessive sweating, rapid heart beat, dizziness, fatigue, and muscle cramps are signs of heat _____ which, if untreated, can lead to heat _____
exhaustion, stroke
Fluid excess is less common than fluid deficiency because the _____ are highly effective in compensating for excessive intake by excreting more urine. _____ failure can lead to fluid retention
kidneys, renal
2 types of fluid excess
- volume excess
- hypotonic hydration (water intoxication) (positive water balance)
In volume excess, both _____ and _____ are retained and the ECF remains _____. It can be caused by _____ hypersecretion or renal failure.
Na+, water, isotonic, aldosterone
In hypotonic hydration, more _____ than _____ is retained or ingested and the ECF becomes _____. This can cause cellular swelling and pulmonary and cerebral edema.
water, Na+, hypotonic
Electrolytes are chemically reactive and participate in _____. They determine _____ potential across membranes. They strongly affect the _____ of body fluids, and affect the body’s water _____ and _____.
metabolism, electrical, osmolarity, content, distribution
major cations
Na+ (sodium)
K+ (potassium)
Ca2+ (calmodulin-dependent protein kinases II or CaM kinases II)
H+ (positively charged hydrogen ions)
_____ is the principle ion responsible for the resting membrane potentials. Inflow of _____ through membrane gates is an essential event in the depolarization that underlies nerve and muscle function.
sodium, sodium
Sodium is the principle cation in _____. It accounts for 90-95% of it’s _____. It is the most significant solute in determining total body _____ and distribution of _____ among the fluid compartments
ECF, osmolarity, water, water
The average adult needs ___ g of sodium per day. The typical american diet contains _____ g per day.
0.5, 3-7
Sodium concentration is coordinated by _____, the “salt retaining hormone” which raises blood pressure. It has a primary role in adjusting sodium _____. Its primary effects are that the urine contains less _____ and more _____ and has a lower _____.
aldosterone, excretion, NaCl (sodium chloride), potassium, pH
_____ is when the plasma sodium concentration is greater than 145 mEq/L. It can be caused by administration if IV saline and can result in water pretension, hypertension and edema.
hypernatremia
hyponatremia is when the plasma sodium concentration is less than ___ mEq/L. It can occur when a person loses large volumes of water via sweat or urine and replaces it with plain drinking water.
130
_____ is the most abundant cation of ICF and is the greatest determinant of its osmolarity and cell volume.
potassium
90% of K+ in glomerular filtrate is reabsorbed by the _____. _____ stimulates the renal secretion of K+.
PCT, aldosterone
_____ imbalances are the most dangerous imbalances of electrolytes.
potassium
The effects of _____ depend on whether the potassium concentration rises quickly or slowly. A concentration greater than 5.5 mEg/L can produce _____ _____.
hyperkalemia, cardiac arrest
_____ is a potassium concentrates less than 3.5 mEq/L. It rarely results from _____ deficiency, and more often from sweating, chronic vomiting or diarrhea. _____ and _____ cells become less excitable resulting in muscle weakness and loss of muscle tone, decrease reflexes, and arrhythmia from irregular electrical activity in the heart.
hypokalemia, dietary, nerve, muscle
Calcium lends strength to the _____;
activates the _____ _____ mechanism of muscle contraction; serves as a second _____ for some hormones and neurotransmitters; activates _____ of neurotransmitters and other cellular secretions; and is an essential factor in _____ _____
bones, sliding filament, messenger, exocytosis, blood clotting
_____ is calcium concentrations greater than 5.8 mEq/L. It can result in alkalosis, hyperparathyroidism, and hypothyroidism. Concentrations greater than 12 mEq/L causes muscular weakness, depressed reflexes, and cardiac arrhythmia.
hypercalcemia
_____ is calcium concentrations less than 4.5 mEq/L. It can result from vit. D deficiency, diarrhea, pregnancy, acidosis, lactation, hypoparahtyroidism, and hyperthyroidism. It increases membrane Na+ permeability, causing nervous and muscular systems to be abnormally excitable. Very low levels can result in tetanus, laryngospasm and death
hypocalcemia
Acid-base balance is one of the most important aspects of _____. _____ depends on enzymes, and enzymes are sensitive to pH. A slight deviation from the normal pH can shut down entire _____ pathways and alter the structure and function of _____. ___ to ___ is the normal pH range of blood and tissue fluid.
homeostasis, metabolism, metabolic, macromolecules, 7.35, 7.45
Challenges to acid-base balance result from _____ constantly producing acid: _____ acid from anaerobic fermentation, _____ acid from nucleic acid catabolism, _____ acids and _____ from fat catabolism, and _____ acid from carbon dioxide.
metabolism, lactic, phosphoric, fatty, ketones, carbonic
Metabolic _____ is when the pH is less than 7.35, and metabolic _____ is when the pH is greater than 7.45.
Acidosis, alkylosis
The pH of a solution is determine solely by its _____ _____.
hydrogen ions
Acids are chemicals that _____ H+ in solutions. _____ acids like HCl ionize freely, giving up most of its H+ and markedly lower the pH of a solution. _____ acids like carbonic acid (H2CO3) ionize only slightly, keeping most H+ chemically bound and not affecting pH.
release, strong, weak
Bases are chemicals that _____ H+. _____ bases like hydroxide ions (OH-) have a strong tendency to bind H+ and markedly raise pH. _____ bases such as the bicarbonate ion (HCO3-) bind less available H+ and has less of an effect on pH.
accept, strong, weak
A _____ is any mechanism that resists changes in pH by converting strong acids or bases to weak ones.
buffer
The urinary and respiratory systems are _____ buffers. The _____ system cannot alter pH as much as the _____ system.
physiological, respiratory, urinary
The 3 major chemical buffers
bicarbonate
phosphate
protein systems
The _____ buffer system account for about 3/4 of all chemical buffering in the body fluids. Its ability is due to certain side groups of their _____ _____ residues. These include _____ side groups which release H+ when pH begins to rise, and _____ side groups that bind H+ when pH gets too low.
protein, amino acid, carboxyl (-COOH), amino (-NH2)
The _____ buffer system functions bes in the lungs and kidneys to constantly remove CO2. To lower pH, the kidneys excrete _____, and to raise pH, they excrete _____ and the lungs excrete CO2.
bicarbonate, HCO3-, H+
A reversible reaction in which CO2+H20–>H2CO3–>HCO3-+H+ and vice versa is important in the _____. One _____ pH by releasing H+, the other _____ pH by binding H+.
ECF, lower, raises
The _____ buffer system has the reaction H2PO4- HPO42- + H+. It is more important in buffering the _____ and _____ tubules.
phosphate, ICF, renal
The _____ buffer system neutralizes 2-3 times as much acid as chemical buffers. Co2 is constantly produced by _____ metabolism and is normally eliminated by the _____ at an equivalent rate.
respiratory, aerobic, lungs
_____ plasma CO2 (decreased pH) stimulates pulmonary ventilation, and _____ plasma CO2 (increased pH) inhibits pulmonary ventilation
increased, decreased
The _____ can neutralize more acid or base than either the respiratory or chemical buffers. The _____ _____ secrete H+ into the tubular fluid. Most bind to bicarbonate, ammonia and phosphate buffers. Bound and free H+ are excreted in the _____. Other buffer systems only reduce H+ concentration by binding it to other chemicals.
kidneys, renal tubules, urine
2 categories of acid-base imbalances
respiratory
metabolic
Respiratory _____ occurs when the rate of alveolar ventilation fails to keep pace with the body’s rate of CO2 production. CO2 accumulates in the ECF and _____ its pH. This occurs in _____ where there is a severe reduction of functional alveoli.
acidosis, lowers, emphysema
Respiratory _____ results from hyperventilation, as when a baby is crying, and CO2 is eliminated faster than it is produced.
alkalosis
Metabolic _____ occurs when the increased production of organic acids such as lactic acid in anaerobic fermentation, ketone bodies as seen in alcoholism, and diabetes mellitus. It can also occur from the ingestion of acidic drugs like aspirin. Also, loss of base can result from chronic diarrhea and laxative overuse.
acidosis
Metabolic _____, though rare, can result from the overuse of bicarbonates such as antacids and IV bicarbonate solution, or the loss of stomach acid from chronic vomiting.
alkalosis
Either the kidneys compensate for pH imbalances of _____ origin, or the respiratory system compensates for pH imbalances of _____ origin. Uncompensated acidosis or alkalosis results in the pH imbalance that the body cannot correct without clinical intervention.
respiratory, metabolic
