Fluid, Electrolyte, and Acid Base Homeostasis
The hormone PTH causes __________.
A decrease in the reabsorption of the phosphate ions
What triggers the release of parathyroid hormone (PTH)?
Decreasing calcium ion concentration of the blood
What triggers the release of parathyroid hormone (PTH?)
Decreasing calcium ion concentration of the blood
Decreased volume and increased concentration of the extracellular fluid (ECF) is defined as:
Dehydration
What is the most common cause for hypernatremia?
Dehydration
What effect does an increase in antidiuretic hormone (ADH) have on the volume of extracellular fluid (ECF)?
ECF increases when antidiuretic hormone (ADH) is present.
Which of the following is an excess accumulation of interstitial fluid?
Edema
Which of the following dissociates into ions when placed in water?
Electrolyte
Which ions are critical for the activation of some enzymes?
Magnesium
What is a major function of potassium ions in the body?
Maintaining resting potential of neurons and muscle cells
The pH of the blood primarily depends upon a normal concentration of:
Hydrogen ions
What determines the hydrostatic pressure of a solution?
Hydrostatic pressure is the force that fluids exert
Predict the effect of hypertonic fluid on a cell.
Hypertonic fluids cause water to move out of the cytosol and the cell shrinks
Mrs. Frykholm is experiencing diabetic ketoacidosis, which causes metabolic acidosis. She has experienced damage to her kidneys from diabetes mellitus. Predict how her body compensates to return her blood pH to normal.
Hyperventilation
What part of the brain controls the thirst mechanism?
Hypothalamus
What leads to respiratory acidosis?
Hypoventilation
Which of the following is a response mechanism for overhydration?
Increased levels of ANP
Water loss from the body that we do not notice is known as:
Insensible water loss
Which of the following statements about ECF is correct?
It is made up of fluids such as plasma and interstitial fluid
Which of the following factors increases an individual's total body water?
Male
Hyperventilation is the compensation for an acid-base imbalance known as:
Metabolic acidosis
The main compensatory mechanism for this acid-base imbalance is hyperventilation.
Metabolic acidosis
Respiratory compensation for this acid-base balance occurs via hypoventilation.
Metabolic alkalosis
Increased water intake causes the hydrostatic pressure in plasma to increase and the osmotic pressure to decrease; as a result, water will __________.
Move from the ECF to the ICF
This acid-base imbalance is caused by an abnormal decrease in ventilation and retention of carbon dioxide.
Respiratory acidosis
To compensate for this acid-base imbalance, the kidneys secrete more bicarbonate ions and reabsorb more hydrogen ions.
Respiratory alkalosis
Hyperventilation causes __________, and hypoventilation causes __________.
Respiratory alkalosis; respiratory acidosis
Through what two systems are carbon dioxide eliminated from the body?
Respiratory and urinary system
A patient with heart failure is administered an intravenous line containing a solution of hypertonic sodium chloride. Select the patient for whom this solution an appropriate choice.
The patient is experiencing overhydration, or hypotonic hydration.
Plasma has a much higher protein content than interstitial fluid.
True
Water obeys the principle of mass balance. In other words, what is gained by the body must equal what is lost by the body.
True
What system is responsible for the most common route of water loss from the body?
Urinary system
How much urine is lost through obligatory water loss each day?
500 mL
Select the blood pH that represents acidosis.
7.24
The normal range of blood pH is __________.
7.35 to 7.45
Bicarbonate is an example of a(n) __________.
Base
The primary role of the phosphate buffer system is to __________.
Buffer intracellular fluid (ICF)
Substances that function to resist large swings in pH are called __________.
Buffers
Overhydration will cause ___________.
Cells to gain water
Why are chlorine ions important?
Chlorine ions are involved in the production of stomach acids
Which of the following accounts for the majority of our total body water?
Cytosol
Determine the pH value that represents a basic, or alkaline, solution.
pH of 10
What statement does NOT describe the methods by which chemical buffer systems operate to maintain pH?
All excess hydrogen ions are removed from the body in the urine.
Select the statement that best describes an acid.
An acid is a chemical that dissociates in water to release a hydrogen ion (H+)
Which hormone influences the concentration of hydrogen ions in the filtrate formed by the kidneys?
Atrial natriuretic peptide (ANP)
The human body has more fluid in the extracellular compartment than in the intracellular compartment.
False
The osmotic pressure gradient, or the force of solutes in a solution, tends to push water away from the solution with the higher osmotic pressure, or the more concentrated solution, by osmosis.
False
When the antidiuretic hormone (ADH) level rises, less water is reabsorbed via the kidneys, the ECF volume decreases, and urine production increases.
False
For which imbalance is the release of antidiuretic hormone (ADH) appropriate?
Fluid and electrolyte imbalance
Which of the following substances is the most acidic?
Gastric juice with a pH of 2
CO2 + H2O ↔ H2CO3 ↔ __________
H+ + HCO3-
Where are the majority of calcium ions stored in the body?
Osseous tissue
Calcium ion reabsorption in the kidneys is stimulated by the hormone __________.
PTH
Which hormone has NO role in potassium ion regulation?
Parathyroid hormone (PTH)
What ion concentration is linked to calcium ion concentration and regulated by vitamin D3 (calcitriol)?
Phosphate ions
What is the most abundant extracellular cation?
Sodium ion
An electrolyte is a __________.
Substance that dissociates into ions when placed in water
If the PCO2 in the plasma increases, what effect will this have on plasma pH?
The pH will decrease
Angiotensin-II restores fluid-homeostasis when dehydration occurs due to inadequate fluid intake. Which of the following is NOT an effect of angiotensin-II?
Vasodilation
Which hormone does NOT regulate fluid balance in the body?
Vitamin D (calcitriol)
What is the main component of all body fluids?
Water
Fluid balance in the human body is roughly equivalent to:
Water balance
In what direction will water move when hypotonic fluids are present in the plasma?
Water is pulled from the interstitial fluid and plasma into the cell
