Ch.27 DSM A&P
Why is there a difference in the ICF percentages in males versus females?
Greater water content of muscle tissue versus adipose tissue
What is the term for an abnormally high concentration of sodium in the ECF?
Hypernatremia
Which of the following is a metabolic acid?
Pyruvic acid Lactic acid Ketone bodies
Important homeostatic adjustments occur in response to changes in __________.
plasma volume or osmolarity
The p in pH refers to ______.
power
The primary role of the carbonic acid−bicarbonate buffer system is to __________.
prevent changes in pH caused by metabolic and fixed acids in the ECF
A metabolic alkalosis can be due to __________.
prolonged vomiting
Hypercapnia, or an elevation of carbon dioxide in the blood, is a sign of __________.
respiratory acidosis
Osmosis allows water to freely cross plasma membranes except in the _____________.
ascending limb of the nephron loop
When the amount of water you gain each day is equal to the amount you lose to the environment, you are in __________.
fluid balance
A loss of bicarbonate ions can lead to ____________________.
metabolic acidosis
Which buffer is the most important buffer in the extracellular fluid?
Carbonic acid-bicarbonate buffer
Which of the following is a cause of a fluid shift?
Excessive sweating Drinking a large volume of water Diarrhea
Which of the following is a basic principle in understanding fluid and electrolyte balance?
The body's content of water or electrolytes will increase if dietary gains exceed losses to the environment.
Severe acidosis (blood pH below 7.0) can be deadly for all of the following reasons
central nervous system function deteriorates and the person become comatose peripheral vasodilation produces a dramatic decrease in blood pressure, potentaily producing circulatory collapse cardiac contractions grow weak and irregular and signs of heart failure may develop
Extracellular fluids in the body consist of
cerebrospinal fluid aqueous humor lymph
A fluid shift of abnormally large amounts of water from the plasma into the interstitial fluid is called __________.
edema
Hyperventilation causes __________.
respiratory alkalosis
The concentrations of the cations and anions in the ICF and ECF are measured in terms of milliequivalents per liter (mEq/L). mEq/L represents the _________________.
total number of positive and negative electrical charges in a liter of solution
What happens when CO2 levels rise?
Additional H+ ions are produced. Additional bicarbonate ions are produced. Blood pH decreases.
In which of the following would water represent the highest percentage of body weight?
Male infant
Which of the following accurately lists the solid components of the human body by weight from greatest to smallest?
Proteins > lipids > minerals > carbohydrates
Given the following data, what would be your diagnosis for this patient? Data: pH 7.3; pCO2 51 mm Hg.; HCO3- 31 mEq/L
Respiratory acidosis
Which term is correctly matched up with its definition?
Salt—an ionic compound consisting of a cation other than hydrogen and an anion other than a hydroxide ion
What is the kidney's response to acidosis?
Secretion of H+ into urine
Which is the most abundant cation in the ECF?
Sodium
What are the principal ions in the extracellular fluid (ECF)?
Sodium, chloride, and bicarbonate
Which of the following occurs when the pH increases (become more basic)?
The carboxyl group (-COOH) of the aminio acid can dissociate acting as a weak acid and releasing an H+. The carboxyl group can become a carboxylate in (-COO-), which adds to the overall negative charge of proteins. The R groups of histidine and cysteine will donate H+ ions.
What would be the effect on the osmotic concentration of blood plasma if you were in the desert without water for a day?
The osmotic concentration of your plasma would increase because of water leaving your body.
What is required for the body to be in acid-base balance?
The production of hydrogen ions is exactly offset by their loss.
Angiotensin II produces a coordinated elevation in the extracellular fluid volume by all of the following mechanisms
decreasing sodium loss in urine triggering the secretion of aldosterone stimulating thirst
When water losses outpace water gains, __________ occurs.
dehydration
Sodium ions enter the ECF by crossing the digestive epithelium via __________.
diffusion and active transport
When a normal pulmonary response does NOT reverse respiratory acidosis, the kidneys respond by __________.
increasing the rate of hydrogen ion secretion into the tubular fluid
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
The hemoglobin buffer system helps prevent drastic alterations in pH when __________.
the plasma PCO2 is rising or falling
A pH below ____ or above _____ is not sustainable for life.
6.8; 7.7
What is the normal pH of ECF?
7.35−7.45
Which of the following is the best way of describing respiratory compensation?
A change in the respiratory rate that helps stabilize the pH of the ECF.
If the partial pressure of CO2 rises in the blood, which of the following happens?
A decrease in pH
What effect does prolonged sweating have on sodium ion levels?
A loss of sodium ions from the ECF
hormones that mediates adjustments to fluid balance and electrolyte balance?
ADH Aldosterone BNP
Which of the following is true regarding antidiuretic hormone (ADH) and its role in regulating fluid and electrolyte balance?
ADH stimulates water conservation by the kidneys and helps to concentrate the urine.
processes for stabilizing body fluid volumes?
Acid-base balance Electrolyte balance Fluid balance
Which of the following hormones causes the conservation of sodium in the kidneys?
Aldosterone
Which of the following accurately describes the role of aldosterone in fluid and electrolyte balance?
Aldosterone is secreted in response to an increasing K+ or decreasing Na+ level in the blood.
Which of the following is accurate regarding the generation of ammonia within kidney tubules?
Ammonium ions (NH4+) are transported into the tubule lumen and are exchanged for Na+ in the tubular fluid. Ammonia (NH3) is toxic to cells and rapidly diffuses into tubular fluid where it reacts with H+ to form NH4+. Tubule cells use glutaminase to break down the amino acid glutamine, which creates either ammonium ions or ammonia as a product.
After a person consumes a meal, the levels of which ion rises in the blood in response to increased acid production in the stomach?
Bicarbonate
What is the term for a substance that opposes a change in pH in a solution and can either remove or replace hydrogen ions?
Buffer
An abnormally high level of which electrolyte could be caused by hyperparathyroidism and would result in kidney stones, confusion, muscle pain, and cardiac arrhythmias?
Calcium
Which of the following is a volatile acid and is a product of the combination of carbon dioxide and water?
Carbonic acid
buffer systems in the ECF or ICF?
Carbonic acid−bicarbonate buffer system Protein buffer system Phosphate buffer system
causes of hyperkalemia?
Chronically low blood pH Kidney damage or disease Some diuretics
Water, by far, is the biggest component of our body fluids. What is the second-largest component of our body fluids?
Electrolytes
Potassium ions are found in the highest concentrations in which of the following fluid compartments?
Intracellular fluid (ICF)
What is an electrolyte?
Ions released through the dissociation of inorganic compounds
sources of water gains?
Liquid Food Metabolism
Which of the following occurs when an individual loses body water?
Plasma volume decreases, and electrolyte concentrations rise.
Which is the most abundant cation in the ICF?
Potassium
principal ions in the intracellular compartment?
Potassium (K+) Phosphate (HPO42-) Magnesium (Mg2+)
Which component makes up the largest portion of the solid components in the body?
Proteins
Why must tubular fluid in the nephron be buffered?
To keep H+ from diffusing back into the blood To allow secretion of H+ to continue To prevent the pH of the urine from becoming too low
Which of the following represents the largest volume of water lost each day under normal physiological conditions?
Urine
ways your body removes electrolytes?
Urine production Sweating Defecation
Why is it more likely for an older person to become dehydrated?
Water content is reduced with age. Ability to concentrate the urine decreases with age. Reduction in sensitivity to ADH and aldosterone with age
What is meant by the term metabolic water?
Water generated during oxidative phosphorylation
Which of the following is accurate regarding water content?
Water makes up about 60 percent of the total body weight of an adult male.
Renin is released in response to all of the following except ____________.
a decrease in K+ concentration in the renal circulation
In a protein buffer system, if the pH increases, the carboxyl group (COOH) of the amino acid dissociates and releases __________.
a hydrogen ion
As a result of the aging process, the ability to regulate pH through renal compensation changes due to __________.
a reduction in the number of functional nephrons
The elderly have an increased risk of respiratory acidosis because of __________.
a reduction in vital capacity
All of the homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the __________.
extracellular fluid
The body content of water will rise if __________.
intake exceeds outflow
Chronic diarrhea causes a severe loss of bicarbonate ions, resulting in __________.
metabolic acidosis
A loss of H+ or a gain in HCO3- can lead to _________.
metabolic alkalosis
Prolonged vomiting and loss of stomach acid causes __________.
metabolic alkalosis
A effects of both respiratory acidosis and metabolic acidosis are especially serious in cases of ________.
near drowning
Fluid and electrolyte balance is maintained by receptors that directly measure _________.
overall osmotic concentration
Blood pH is normally between __________.
pH 7.35−7.45
A mismatch between carbon dioxide generation in peripheral tissues and carbon dioxide excretion at the lungs is a __________.
respiratory acid−base disorder
Ketone bodies accumulate in the blood during are associated with __________.
starvation
responses during the regulation of metabolic alkalosis?
H+ ions are generated. HCO3- ions are secreted. Buffer systems other than carbonic acid-bicarbonate donate H+
responses in the regulation of acute respiratory acidosis?
H+ ions are secreted into the urine. Increased respiratory rate Buffer systems other than the carbonic acid-bicarbonate system accept H+.
Which of the following contributes to an increase in H+?
H+ is increased by cellular respiraton. H+ is increased by the diet along the digestive tract. H+ is increased by muscle metabolism.
basic principles for understanding fluid and electrolyte balance?
Homeostatic mechanisms respond to changes in the ECF. Water and electrolyte content in the body is a balance between intake and losses. No receptors exist for fluid and electrolyte balance.
What is the term for an abnormally low concentration of potassium in the blood?
Hypokalemia
major causes of metabolic acidosis
Impaired ability to excrete H+ at the kidneys A severe bicarbonate loss Production of a large number of fixed or metabolic acids
associated with a sensation of increased thirst
Increase in the production of angiotensin II Increase in renin secretion Increase in the production of ADH
Which of the following might be a response to respiratory acidosis?
Increased respiratory rate
The loss of mineral content with age is frequently due to what cause?
Loss of muscle and bone mass
An ECF?
Lymph Cerebrospinal fluid Plasma
Which of the following is NOT a principal ion in the extracellular compartments?
Magnesium ion (Mg2+)
Given the following data, what would be your diagnosis for this patient? Data: pH 7.32; PCO2 38; HCO3- 20 mEq/L
Metabolic acidosis
What would be the response of the body to an increase in ECF volume if you were to drink a large quantity of a sports drink?
Natriuretic peptides would be released by cardiac muscle cells. Increased water and sodium loss in the urine Decreased thirst
A patient presents with a blood pH of 7.5, a PCO2 of 32, and a normal HCO3-. What is the likely cause of this patient's abnormal lab values?
Panic attacks causing acute respiratory alkalosis
Which of the following descriptions is correct?
Respiratory acid-base disorders result from a mismatch between CO2 generation in peripheral tissues and CO2 excretion by the lungs.
What would happen if you ate a large quantity of salty potato chips without drinking anything?
Secretion of ADH would increase.
Deviations outside of the normal pH range due to increases in hydrogen ion concentrations would
alter protein structure change the activities of important enzymes disrupt the stability of cell membranes
The most common problems with electrolyte balance are caused by __________.
an imbalance between sodium gains and losses
Under normal circumstances, during respiratory acidosis the chemoreceptors monitoring the PCO2 of the plasma and CSF will eliminate the problem by calling for __________.
an increase in pulmonary ventilation rates
