A & P II ch 27 - Fluid, Electrolyte, & Acid-Base Balance
Terms in this set (94)
Intracellular fluid (ICF) is found only within
the cells of the body
The extracellular fluid (ECF) consists of the
all of the above: plasma and lymph;
interstitial fluid; cerebrospinal fluid
The principal cation in intracellular fluid is
When water is lost, but electrolytes are retained,
osmosis moves water from the ICF to the ECF.
When pure water is consumed
the ECF becomes hypertonic to the ICF
Consuming a meal high in salt will
result in a temporary increase in blood volume.
stimulates water intake;
stimulates water conservation by the kidneys.
is secreted in response to elevated levels of potassium in the blood; promotes sodium retention in the kidneys.
Which of the following will stimulate thirst?
drying the mucosa of the mouth and pharynx;
angiotensin II acting on the hypothalamus;
an increase in the osmotic pressure of interstitial fluid within the hypothalamus
The ions in highest concentration in the intracellular fluid are
proteins, potassium, and phosphate.
The ions in highest concentration in the extracellular fluid are
sodium, chloride, and bicarbonate
Excess hydrogen ion is eliminated from the body largely by
The amount of potassium excreted by the kidneys is regulated mainly by
Calcium reabsorption by the kidneys is promoted by the hormone
In a lean adult male, the body consists of about ________ percent water.
The primary role of the carbonic-acid-bicarbonate buffer system is to
limit pH changes caused by organic and fixed acids.
About two-thirds of the body fluid is within cells and is termed ________ fluid.
Hypoventilation leads to
In response to respiratory alkalosis, the
kidneys retain more hydrogen ions.
Prolonged vomiting can result in
A person with emphysema will exhibit signs of
chronic respiratory acidosis
A person with poorly controlled diabetes mellitus will develop
A patient on a ventilator subjected to excessive minute volume is at risk for
A person who consumes large amounts of sodium bicarbonate ("baking soda") to settle an upset stomach risks
Severe kidney damage (such as glomerulonephritis) often leads to
Substances that can carry electrical current across cell membranes are called
Which hormone stimulates the thirst mechanism?
In an adult female, the body consists of about ________ percent water.
All of the following are components of ECF, except
Which hormone plays a central role in determining the rate of sodium reabsorption and potassium secretion?
Exchange between the two main subdivisions of ECF occurs primarily at the
Which hormone(s) is released by heart muscle in response to excessive chamber volume?
A patient who has been both vomiting and having diarrhea is losing ________ from his body.
all of the above: water; sodium;
bicarbonate ion; hydrogen ion
Which hormone most affects the osmolarity of blood?
Approximately ________ liters of peritoneal fluid are produced and reabsorbed each day.
The most common problems with electrolyte balance are caused by an imbalance between gains and losses of
The release of atrial naturetic peptides from the heart will cause the body to
decrease ECF and excrete sodium ions.
Angiotensin II produces a coordinated elevation in the ECF volume by
stimulating thirst; causing the release of ADH;
triggering the production and secretion of aldosterone
Which of the following descriptions best fits the acid-base disorder metabolic alkalosis?
consequence of prolonged vomiting
A chemical that minimizes changes in the pH of a body fluid by releasing or binding hydrogen ion is called a(n)
Secretion of potassium into the urine is
increased by aldosterone; associated with the reabsorption of sodium from the distal tubules and collecting ducts.
To reduce brain swelling by pulling water out of brain cells, a substance can be injected intravenously to increase the osmotic pressure of interstitial fluid. Which of the following properties can this substance not have in order to be effective?
permeable to brain plasma membranes
Which of the following descriptions best fits the acid-base disorder respiratory acidosis?
consequence of reduced alveolar ventilation, for example due to emphysema
When the pH of the extracellular fluid drops, the
kidneys excrete more hydrogen ions;
kidneys excrete fewer bicarbonate ions
Which of the following descriptions best fits the acid-base disorder respiratory alkalosis?
consequence of hyperventilation, for example in fever or mental illness
The activity that occurs in the body to maintain calcium homeostasis occurs primarily in the
bone, digestive tract, kidneys
All of the homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the
All water transport across cell membranes and epithelia occur passively, in response to
osmotic gradients and hydrostatic pressure
As a result of the aging process, the ability to regulate pH through renal comensation declines due to
a reduction in the number of functional nephrons
Atrial natriuretic peptide hormone
reduces thirst, blocks the release of ADH, blocks the release of aldosterone
The body content of water or electrolytes will rise if
intake exceeds outflow
Chronic diarrhea causes a severe loss of bicarbonate ions resulting in
Compensation for metabolic alkalosis involves
decreased pulmonary ventilation, increased loss of bicarbonates in the urine
The concentration of potassium in the ECF is controlled by adjustments in the rate of active secretion
along the distal convoluted tubular and collecting system of the nephron
The condition that results when the respiratory system cannot eliminate all the carbon dioxide generated by peripheral tissues is
Deviations outside of the normal pH range due to changes in hydrogen ion concentrations
disrupt the stability of cells membranes, alter protein structure, change the activities of important enzymes
Disorders that have the potential for disrupting pH balance in the body include
emphysema, renal failure, neural damage, CNS disease, heart failure, hypotension
Electrolyte balance primarily involves balancing the rates of absorption across the digestive tract with rates of loss at the
kidneys and sweat glands
The exchange between plasma and interstitial fluid is determined by the relationship between the
net hydrostatic and net colloid osmotic pressures
Extracellular fluids in the body consist of
interstitial fluid, blood plasma, lymph, cerebrospinal fluid, synovial fluid, serous fluids, aqueous humor, perilymph, endolymph
The force that tends to push water out of the plasma and into the interstitial fluid is the
net hydrostatic pressure
The hemoglobin buffer system helps prevent drastic alterations in pH when
the plasma PCO2 is rising or falling
If the ECF is hypertonic with respect to the ICF, water will move
from the cells into the ECF until osmotic equilibrium is restored
Important examples of organic acids found in the body are
lactic acid and ketone bodies
Important homeostatic adjustments occur in response to changes in
plasma volume or osmolarity
In a protein buffer system, if the pH increases a carboxyl group (COOH) of an amino acid dissociates and releases
a hydrogen ion
Increasing or decreasing the rate of respiration can have a profound effect on the buffering capacity of body fluids by
lowering or raising the PCO2
The lungs contribute to pH regulation by their effects on the
carbonic acid-bicarbonate buffer system
The major causes of metabolic acidosis are
production of a large number of fixed or organic acids, impaired ability to excrete H+ at the kidneys, a severe bicarbonate loss
A mismatch between carbon dioxide generation in peripheral tissues and carbon dioxide excretion at the lungs is a
respiratory acid-base disorder
The most common problems with electrolyte balance are caused by
an imbalance between sodium gains and losses
The most frequent cause of metabolic acidosis is production of
a large number of fixed or organic acids
The most important factor affecting the pH in body tissues is carbon dioxide concentration
carbon dioxide concentration
The most important factor affecting the pH in body tissues is
Nearly two-thirds of the total body water content is
intracellular fluid (ICF)
Normal pH values are limited to the range between
Physiological adjustments affecting fluid and electrolyte balance are mediated primarily by
ADH, aldosterone, ANP & BNP
The principal ions in the ECF are
sodium, chloride, bicarbonate
Pulmonary and renal mechanisms support the buffer systems by
secreting or generating hydrogen ions, controlling the excretion of acids and bases, generating additional buffers when necessary
The rate of tubular secretion of potassium ions changes in response to
alterations in the potassium ion concentration in the ECF, changes in pH, aldosterone levels
The renal response to acidosis is limited to
secretion of H+ and generation or reabsorption of HCO3
Respiratory alkalosis develops when respiratory activity
lowers plasma PCO2 to below-normal levels
The risk of respiratory acidosis in the elderly is increased due to
a reduction in vital capacity
Secretion of aldosterone occurs in response to
a drop in plasma volume at the juxtaglomerular apparatus, a decline in filtrate osmotic concentration at the DCT, high potassium ion concentrations
Sodium ions enter the ECF by crossing the digestive epithelium via
facilitated diffusion and active transport
The two important effects of increased release of ADH are
reduction of urinary water losses and stimulation of the thirst center
When an individual loses body water
plasma volume decreases and electrolyte concentrations rise
When a pulmonary response cannot reverse respiratory acidosis, the kidneys respond by
increasing the rate of hydrogen ion secretion into the filtrate
When carbon dioxide concentrations rise, additional hydrogen ions are produced and the
pH goes down
Whenever the rate of sodium intake or output changes, there is a corresponding gain or loss of water that tends to
keep the sodium concentration constant
When the amount of water you gain each day is equal to the amount you lose to the environment, you are in
When the PCO2 increases and additional hydrogen ions and bicarbonate ions are released into the plasma, the
pH goes down, acidity rises
When the production of hydrogen ions in your body is precisely offset by their loss, you are in
When water is lost but electrolytes are retained, the osmolarity of the ECF rises and osmosis then mvoes water
out of the ICF and into the ECF until isotonicity is reached