A&P II Chapter 25
which hormone stimulates the first mechanism
ADH
when the pH rises above 7.45, a state of _________ exists
alkalosis
Which body system is not involved in fluid, electrolyte, and acid-base balance?
all systems produce metabolic wastes and therefore, ae involved in fluid and electrolyte balance
What would happen to the blood PCO2 of a patient who has an airway obstruction?
blood PCO2 would increase, resulting in respiratory acidosis
the hemoglobin buffer system exists in
both intracellular fluid and extracellular fluid
A chemical that minimizes changes in the pH of a body fluid by releasing or binding hydrogen ion is called a(n)
buffer
A(n) __________ consists of a combination of a weak acid and its associated anion
buffer system
when the pH of the extracellular fluid drops, the kidneys
excrete more hydrogen ions and reabsorb bicarbonate ions
Consuming a meal high in salt will
result in a temporary increase in blood volume
Normal K+ concentration in extracellular fluid is ______mEq/L
3.5 - 5.0
In an adult female, the body consists of about _______ percent water
50
In an adult male, the body consists of about ________percent water
60
The normal pH range for extracellular fluid is
7.35 - 7.45
Describe a fluid shift
A fluid shift is the rapid movement of water between the ECF and ICF in response to an osmotic gradient.
Define acidemia and alkalemia
Acidemia is when pH decreases below 7.35 and alkalemia is when pH increases above 7.45.
What effect does aldosterone have on sodium ion concentration in the ECF?
Aldosterone increases urinary sodium retention and therefore increases sodium ion concentration in the EFC
Summarize the relationship between PCO2 levels and pH
An inverse relationship occurs between the levels of PCO2 and pH
What effect does inhibition of osmoreceptors have on ADH secretion and thirst?
Decreases ADH secretion and suppresses thirst
which substance plays a central role in determining the rate of sodium reabsorption?
aldosterone
Explain dehydration and its effect on the osmotic concentration of blood
Dehydration occurs when water losses outpace water gain causing the osmotic concentration of blood plasma to increase
Define hypokalemia and hyperkalemia
Hypokalemia is defined as blood K+ levels below 3.5 mEq/L and hyperkalemia is defined as blood K+ levels above 5.0 mEq/L.
Which fluids are buffered by the phosphate buffer system?
ICF, urine
Describe metabolic acidosis
Metabolic acidosis occurs when pH decreases due increased numbers of fixed and metabolic acids, from bicarbonate loss, or from depletion of bicarbonate reserve when hydrogen ions are not adequately excreted by the kidneys.
Describe metabolic alkalosis
Metabolic alkalosis occurs when pH increases due to the removal of hydrogen ions when bicarbonate ion concentrations are elevated.
Define mineral balance.
Mineral balance occurs when ion gains are equal to ion losses.
The principal cation in cytoplasm is
Potassium
Identify factors that cause potassium excretion
Potassium excretion is caused by an increase in aldosterone stimulation and when the pH of the ECF increases.
How would a decrease in pH of body fluids affect the respiratory rate?
Respiratory rate would increase
what is the primary challenge to acid-based homeostasis?
The primary challenge is that the body generates a variety of acids during normal metabolic operations causing a decrease in pH
A(n) __________ acid is an acid that can leave solution and enter the atmosphere
Volatile
Identify routes of fluid loss from the body.
Water can be lost during urination, evaporation at skin and lungs, and in feces.
When the body pH falls below 7.35, __________results
acidemia
The amount of potassium excreted by the kidneys is regulated mainly by
aldosterone
what intermediate compound formed from water and carbon dioxide directly affects the pH of the ECF?
carbonic acid
Antidiuretic hormone does not
cause water to shift out of the ICF.
Intracellular fluid is found only within
cells of the body
The ions in highest concentration in the extracellular fluid are sodium and
chloride
which of the following descriptions best fits the acid-base disorder respiratory acidosis?
consequence of reduced alveolar ventilation, for example due to emphysema
which of the following descriptions best fits the acid-based disorder metabolic alkalosis?
consequences of prolonged vomiting
which of the following is required as a cofactor for hemoglobin synthesis?
copper
The release of natriuretic peptides from the heart will cause the following response
decrease of ADH release
Increased blood volume will
decrease thirst
Homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the
extracellular fluid
A(n) _____acid is an acid that can not leave solution and enter the atmosphere
fixed
Small amounts of ________ acids are generated during the catabolism of amino acids and compounds that contain phosphate groups
fixed
Rapid water movement between the extracellular fluid and the intracellular fluid is termed
fluid shift
Excess hydrogen ion is eliminated from the body largely by
kidneys
Which organs are primarily responsible for regulating the potassium ion concentration in the ECF?
kidneys
the primary role of the carbonic acid-bicarbonate buffer system is to
limit pH changes caused by organic and fixed acids
if the kidneys are conserving HCO3- and eliminating H+ in acidic urine, which is occurring: metabolic alkalosis or metabolic acidosis?
metabolic acidosis
A person who consumes large amounts of sodium bicarbonate ("baking soda") to settle an upset stomach risks
metabolic alkalosis
Prolonged vomiting can result in
metabolic alkalosis
When water is lost, but electrons are retained,
osmosis moves water from the intracellular fluid to the extracellular fluid
All of the following factors are consistent with hypokalemia except
overuse of diuretics
Identify the body's three major buffer systems.
phosphate buffer system, protein buffer system, and the carbonic acid-bicarbonate buffer system
Which solid component makes up most of the body mass?
protein
Hypoventilation leads to
respiratory acidosis
Describe the carbonic acid-bicarbonate buffer system
the carbonic acid-bicarbonate buffer system uses the hydrogen ions created by metabolic and fixed acids to generate carbonic acid which dissociates into H2O and CO2, which can be eliminated by the lungs
Which buffers/buffer system exist(s) only in intracellular fluid?
the phosphate buffer system
_____ play(s) a key low in maintaining acid-based homeostasis by eliminating carbon dioxide
the respiratory system
Hyperventilation will _______ pH
to raise (increase)
About two-thirds of body's fluid is within cells and is termed ________fluid
vital
metabolic water is
water produced through catabolic processes
When is your body in acid-base balance?
when the production of hydrogen ions is precisely offset by their loss and when the pH of body fluids remains within normal limits