Flashcards in Fluid, Electrolyte and Balance Deck (155):
Between an adult male, female, elder, and baby which has the higher body water content?
the baby due to low body fat therefore low bone mass
Why do males have 10 percent more body water content that females?
Males have more skeletal muscle than women who have higher body fat
What are the 2 main fluid compartments?
Intracellular fluid and extracellular fluid
What are the 2 subparts of the extracellular fluid? Percentages?
What is the fluid in the blood called?
Which of the compartments consist of 2/3 total fluid content?
What is the fluid between cells called?
Which of the compartments consist of 1/3 total fluid content?
What is the percentage of the ICF in the body?
What is the percentage of ECF in the body?
What is the percentage of the total body weight of ECF and ICF?
do not dissociate in water; no charged particles are created
dissociate into ions in water; ions conduct electrical current
What are some examples of electrolytes?
acids, bases, salts, and some proteins
What are some examples of nonelectrolytes?
glucose and most organic molecules
What is the major cation in the ECF?
What is the major anion in the ECF?
What is the major cation in the ICF?
What is the major anion in the ICF?
Where are the electrolyte concentrations similar except for higher protein content of plasma?
Where are there more proteins than in plasma?
Where do exchanges between plasma and IF occur?
Across capillary walls
Where do exchanges between IF and ICF occur?
Across plasma membranes
What must occur for the body to remain stable?
its inout through ingestion or metabolic production = its output through excretion or metabolic consumption
Which 2 factors are regulated to maintain fluid balance?
1. ECF osmolality
2. ECF volume
How is ECF osmolality regulated?
must be regulated to prevent swelling or shrinking of cells
What is ECF osmolality involved in maintaining?
How is ECF volume regulated?
must be regulated to help maintain BP
What is ECF volume involved in maintaining?
maintaining sodium balance
What leads to net water flow?
a change in solute concentration in any compartment
Controlling ECF osmolality prevents what?
changes in ICF volume
What occurs when water leaves the cell to enter the ECF?
What occurs when water moves into the cell from the ECF?
What happens to the cell in a hypertonic solution?
the cell shrinks
What happens to the cell in a hypotonic solution?
the cell lysis or burst
What is the total amount of water intake/output in a day?
What are the ways water is taken into the body? Percentages?
What are the ways water is released from the body?
Insensible loss via skin and lungs: 28%
What is the range of plasma osmolality maintained?
What causes rise in osmolality?
stimulates thirst and stimulates ADH release
What causes a decrease in osmolality?
inhibits thirst and ADHA RELEASE
ADH stimulation does what to urine output?
decreases urine output
ADH inhibition does what to urine output?
increases urine output
What drives water intake?
Where in the brain is the thirst center located?
in the hypothalamus
Which 3 factors activate the thirst center in the hypothalamus?
1. Dry mouth
2. Decrease in BP and BV
3. Hypothalamic osmoreceptors
How are water reabsorption and excretion are adjusted through changes in what?
What monitors ECF solute concentration and trigger or inhibit ADH release?
What leads to the events of water reabsorption and small volume of concentrated urine?
ECF osmolality stimulates ADH release
What leads to to water reabsorption and large volume of dilute volume?
ECF osmolality inhibits ADH release
What is the term for excessive water loss?
What are 3 major ways dehydration occurs?
1. Diabetes insipidus
2. Excessive water loss
3. insufficient water intake
What are the effects of the cell of dehydration?
the cell shrinks
What is the term for excessive water gain?
What are 3 major ways overhydration occurs?
1. Rapid ingestion of excess water
2. Inappropriate ADH secretion
3. Renal failure
What are the effects of the cell due to hypotonic hydration?
the cell swells
What is the term for atypical accumulation of interstitial fluid?
Changes in what affects plasma volume, BP and CF and IF volumes?
change in plasma NA+ levels
How does sodium control ECF volume and water distribution?
this is because water follows salt
What are the three determinations of concentration of Na+ in ECF?
1. determines ECF osmolality
2. remains stable because water always follows salt to maintain osmotic equilibrium
3. regulated by controlling water or loss or gain
What are the 2 determination of total body content of Na+?
1. regulated by controlling Na+ loss or gain
2. determines ECF volume and BP
How do the kidneys maintain total body Na+ content?
by regulating rate of sodium excretion
What brings the body sodium content and ECF volume back into line?
changes in blood volume or pressure trigger neural and hormonal
Which two processes allow the kidneys adjust amount of salt excreted?
1. amount of sodium filtered
2. amount of sodium reabsorbed
What controls amount of sodium filtered?
controlled by regulating GFR
What controls amount of sodium reabsorbed?
controlled by renin-angiotensin-aldosterone mechanism
Blood volume is monitored and regulated to maintain what?
What determine fluid volume?
What determines blood pressure?
What monitors BP and so indirectly monitor sodium content?
What plays the biggest role in regulation of sodium by kidneys?
What occurs when aldosterone is low?
no sodium reabsorption occurs beyond DCT
What occurs when aldosterone is high?
all remaining Na+ is reabsorbed in DCT and collecting duct
What are the 2 triggers for aldosterone released?
1. renin-angiotensin-aldosterone mechanism
2. elevated K+ levels in ECF
What is the role of ANP?
controls Na+ reabsorption
What are the 2 effects of ANP?
1. promotes excretion of sodium and water
2. decreases BV and BP
What is the importance of potassium?
effects resting membrane potential on neurons and cardiac muscle cells
increased ECF potassium concentration
decreased ECF potassium concentration
What causes depolarization and reduced excitability?
What causes hyperpolarization and nonresponsiveness?
As K+ leaves the cell and H+ enters the cell what effect does this have on the ECF?
ECF potassium concentration rises with acidosis
As K+ enters the cell and H+ leaves the cell, what effect does this have on the ECF?
ECF potassium concentration falls with alkalosis
What are three major events calcium in the ECF is important?
1. blood clotting
2. secretory activities
3. muscle contraction
decreased ECF calcium concentration
increased ECF calcium concentration
What is the result of hypocalcemia?
inhibits neurons and muscle cells and may cause heart arrhythmias
What is the result of hypocalcemia?
increases neuromuscular excitability and can lead to muscle tetany
ECF calcium levels closely are regulated by what?
PTH promotes increase in calcium levels by targeting which 3 organs?
3. small intestine
Most filtered calcium ions and phosphate ions are reabsorbed where?
What does PTH inhibit what?
ion reabsorption; decreases transport maximum
What 2 events occur when ECF calcium is low?
1. more calcium ions are reabsorbed
2. more phosphate is excreted
Changes in what alter tertiary structure of proteins?
hydrogen concentration of ECF
Neurons become less excitable -> CNS depression
Neurons become hyperexcitable -> respiratory arrest
What is the normal pH of arterial blood?
Fat metabolism is broken down into
fatty acids and ketone bodies
Anaerobic respiration of glucose is broken down into
Catabolism of proteins is broken down into
phosphoric acid and sulfuric acid
H+ gain through metabolism must be attached with H+ loss by?
1. removal of CO2 by respiration
2. excretion of H+ in urine
H+ concentration is regulated sequentially by which 3 mechanisms?
Chemical buffer systems -> brain stem respiratory centers -> renal mechanisms
Dissociate only partially; only small effect on pH
Dissociate completely in water; can dramatically affect pH
Dissociate completely in water; quickly tie up hydrogen ions
dissociate only partially
System of one or more compounds that resists pH changes by reversibly binding hydrogen ions
What are the 3 major chemical buffer systems?
Mixture of H2CO3 and NaHCO3
bicarbonate buffer system
only important ECF buffer
bicarbonate buffer system
If a strong acid is added to a bicarbnonate buffer system, what happens to the pH?
pH decreases slightly
If a strong base is added to a bicarbonate buffer system what occurs to the pH?
the pH rises only slightly
What type of buffer system is important in buffering urine and ICF?
phosphate buffer system
what are the components of sodium salts in the phosphate buffer system?
dihydrogen phosphate and monohydrogen phosphate
If a strong acid is added to a phosphate buffer system what happens to the pH?
If a strong base is added to a phosphate buffer system what happens to the pH?
What type of buffer system involves plasma and in cells?
Protein buffer system
True or false. A protein molecule can function reversibly as a weak acid or weak base
True or False. When pH falls, amino groups release H+
False, amino groups bind H+
True or false. When pH rises, organic acid or carboxyl groups release H+
Respiratory and renal system are what type of buffering systems?
physiological buffering systems
What are the 3 functions of the physiological buffering system?
1. regulate amount of acid or base in body
2. act more slowly than chemical buffer systems but have more buffering power
What do lungs eliminate by eliminating CO2?
volatile acid carbonic acid
What do kidneys eliminate by cellular metabolism?
nonvolatile acids produced by cellular metabolism
What are the 3 effects if pressure in CO2 or plasma rises?
1. respiratory rate and depth increase
2. more CO2 removed from blood
3. reaction shifts to left and reduces H+ concentration
What are the 3 effects if plasma falls?
1. more CO2 accumulates in blood
2. respiratory rate and depth decrease
3. reaction shifts to right and increases hydrogen ions concentration
What are the 2 ways kidneys regulate acid-base balance by adjusting amount of HCO3-?
1. conserving or generating new HCO3-
2. Excreting HCO3-
When plasma decreases kidneys excrete large quantities what happens to the pH?
plasma H+ increases toward normal
When plasma increases kidneys reabsorb HCO3- what happens to the plasma H+?
Plasma H+ decreases toward normal
What is the term caused by too much CO2 in the blood?
what is the term caused by too little CO2 in the blood?
Respiratory acidosis and alkalosis are indicated by what?
Blood partial pressure of CO2 levels above or below normal range
What is the term for all abnormalities other than those caused by excess retention or loss of CO2?
Metabolic acidosis or alkalosis
Metabolic acidosis and alkalosis are indicated by what?
indicated by HCO3- levels above or below normal range
What causes hypoventilation, shallow breathing and impaired gas exchange?
What happens to the CO2 and blood pH in respiratory acidosis?
1. CO2 accumulates in blood, lower than normal range
2. Blood pH drops
What causes hyperventilation?
What happens to the CO2 and blood pH in respiratory alkalosis?
1. CO2 eliminated faster than produced, above normal range
2. Blood pH rises
What is cause by ingesting too much alcohol, excessive loss of HCO3-, accumulation of lactic aid, and ketosis?
What happens to the HCO3- and blood pJ in metabolic acidosis?
low blood and HCO3- levels
What does vomiting acidic stomach contents and intake of excess antacids lead to?
What happens to the blood pH and HCO3- in metabolic alkalosis?
rising blood pH and HCO3- levelsn
True or false. If acid-base imbalance due to malfunction of one physiological buffer system, other system tries to compensate
Respiratory system attempts to correct metabolic acid-base imbalances b what?
by changing respiratory rate and depth
Kidneys attempt to correct respiratory acid-base imbalances by what?
retaining or eliminating HCO3-
How does the respiratory system try to compensate for metabolic acidosis?
increasing rate and depth of breathing
How does the respiratory system compensate for metabolic alkalosis?
with slow, shallow breathing
How do the kidneys compensate for respiratory acidosis?
by retaining more HCO3-
How do the kidneys compensate for respiratory alkalosis?
kidneys compensate by excreting more HCO3-
Low blood, High Pco2 and high HCO3- levels
Low blood, low HCO3-, and Pco2 below normal
High blood pH, high HCO3-, and Pco2 above normal