Fluid, electrolyte, and acid-base balance Flashcards
INTRACELLULAR FLUIDS make up about _____ of the fluid in the body
TWO-THIRDS
EXTRACELLULAR FLUIDS make up about ____ of the fluid in the body
ONE-THIRD
WAYS THAT FLUID GETS INTO THE BODY
INGESTED FLUIDS
INGESTED FOODS
METABOLIC WATER - created by chemical reaction in the body
WHAT ARE SOME WAYS THAT FLUIDS LEAVE THE BODY
KIDNEYS
SKIN
LUNGS
GI TRACT
______ is the principle mechanism to regulate fluid intake
THIRST
WHERE IS THE THIRST MECHANISM BE CENTERED IN OUR BODY
HYPOTHALAMUS
A DECREASE IN BLOOD VOLUME CAUSES ____________
A DECREASE IN BLOOD PRESSURE
osmoreceptors (a type of mechanoreceptors) in the hypothalamus detect an increased ratio of solutes to fluid in the blood ( ______ ______ ______ )
INCREASED OSMOTIC PRESSURE
our sensation of thirst tends to lag behind our need for water, so it is good to replenish fluids during activities or high temps ____ ____ ____ _____
BEFORE you feel thirsty
3 hormones that are key to controlling fluid and solute loss from body
ADH - from posterior pit/hypothalamus
ANP - from heart
ALDOSTERONE - from adrenal cortex
ADH is released by the posterior pituitary/hypothalamus in response to
an increase in osmotic pressure (decrease in water concentration in body fluids)
ADH stimulates
WATER REABSORPTION BY THE KIDNEYS
ANP is released by the heart due to
increased blood volume, stretching the atria
ANP stimulates
secretion of sodium and chloride by the kidneys, water follows, and blood volume decreases
decreased blood pressure triggers the kidneys to release
the enzyme RENIN
renin promotes the conversion of the plasma protein _____ into ____
ANGIOTENSINOGEN INTO
ANGIOTENSIN 1
An enzyme in the lungs conveys angiotensin 1 into
angiotensin II
angiotensin II stimules
the release of ALDOSTERONE from the adrenal cortex
ALDOSTERONE promotes
the reabsorption of sodium by the kidneys and the obligatory reabsorption of water
if osmolarity of interstitial fluid increase, such as if the body becomes ______, cells may shrink as fluid leaves cells and moves to interstitial fluid
DEHYDRATED
if osmolarity of interstitial fluid, on the other hand, decreases, cells may
swell as fluids move into cells
***could cause cells to burst
SUBSTANCE THAT WHEN DISSOLVED IN WATER DISSOCIATES INTO POSITIVE AND NEGATIVE IONS forming a solution that can conduct an electrical current
ELECTROLYTE
Most examples of electrolytes can be classified as
MINERALS
most abundant electrolyte (90%) extracellular cation (+).
key roles in fluid and electrolyte balance and action potentials in neurons and muscles.
controlled by aldosterone, ADH, and ANP
SODIUM
most prevalent anion (-)
key roles in fluid and electrolyte balance, part of HCL in the stomach
controlled by aldosterone
CHLORIDE
Most abundant cation in intracellular fluid
fluid electrolyte balance, nerve impulse transmission, muscle contraction, pH
controlled by aldosterone
POTASSIUM (K+)
second most prevalent extracellular anion (-)
fluid, electrolyte, acid-base balance, pH
the kidneys either form or excrete it
BICARBONATE (HCO3-)
most abundant mineral in the body, with 98% in bones and teeth, 1% in body fluids and other tissues like muscle
blood clotting, neurotransmitter release, muscle tone, nerve impulses, muscle contraction
levels controlled by several hormones: PTH, calcitriol (vit D), calcitonin (CT)
CALCIUM (Ca++)
most esists as part of calcium phosphate salts in bones and teeth. about 15% exists as various ions (H2PO4-, HPO4–, AND PO4—). H2PO4- is the form most often mentioned as an intracellular anion
buffer H+, part of ATP, many organic molecules
PTH and calcitriol in great part regulate levels
PHOSPHATE
much in bones (54%), the rest in intracellular fluids (45%) and extracellular fluids (1%)
cofactor in many enzymes needed for metabolism of CHO and PRO, sodium/potassium pump, neuromuscular functioning, synaptic transmission, myocardial fucntion
several factors influence secretion by kidneys; hypercalcemia, hypermagnesemia, PTH, and acidosis are among them
MAGNESIUM
as electrolytes are often dissolved in body fluids, ELECTROLYTE IMBALANCES OFTEN ACCOMPANY
FLUID IMBALANCE
CAUSES OF ELECTROLYTE/FLUID IMBALANCE
excessive perspiration
vomiting or diarrhea
hormonal problems
dietary insufficiency or excess supplementation
may also occur due to medications, kidney probs, diabetes, heart failure, cancer, and numerous other conditions
electrolyte/fluid imbalances may have MILD TO SEVERE CONSEQUENCES such as
muscle spasms or tenting, fatigue, or cardiac arrhythmias
____ is associated with hydrogen ions (H+) and some negative ions
ACIDS
____ dissociate in water to hydroxyl ions (OH-) and some positive ions
BASES
____ dissociate in water into positive and negative ions, neither of which is hydrogen or hydroxl
SALTS
on the pH scale, LOWER NUMBERS ARE ____ ____ while HIGHER NUMBERS ARE ____ ____
STRONG ACIDS;
STRONG BASES
7 IS NEUTRAL
3 notable MECHANISMS TO MAINTAIN ACID-BASE BALANCE
RENAL REGULATION
RESPIRATION
BUFFER SYSTEMS
KIDNEYS PROVIDE LONG-TERM acid base balance.
they can EXCRETE ____ ____ and REABSORB ____ _____
HYDROGEN IONS (H+)
BICARBONATE (HCO3-)
RESPIRATION is a way to control the acid-base balance, especially in the
SHORT-TERM
an increase in CO2 in body fluids increases ______
ACIDITY (lowers pH)
BY ELIMINATING CO2 through breathing, we produce less carbonic acid, and less will dissociate into H+ ions, thereby
REDUCING ACIDITY
most ____ ____ in the body consist of a weak acid and the salt of that acid, which starts as a weak base
BUFFER SYSTEMS
buffers prevent large pH swings by
CONVERTING STRONG ACIDS AND BASES INTO WEAK ONES VERY QUICKLY (milliseconds)
inadequate exhalation of CO2 causes blood pH to drop.
emphysema, pulmonary edema, brain stem injuries, airway obstruction, and respiratory muscle problems - all can lead to this problem
RESPIRATORY ACIDOSIS
loss of HCO3 in body fluids from severe diarrhea, kidney dysfunction, accumulation of an acid (ketosis), and kidney failure to remove H+
METABOLIC ACIDOSIS
hyperventilation leads to a loss of CO2
altitude, pulmonary disease, CVA, severe anxiety
increasing levels of CO2 can help (bag breathing)
RESPIRATORY ALKALOSIS
Loss of acids (vomiting loss of Hal), excessive intake of alkaline meds, diuretics, severe dehydration
METABOLIC ALKALOSIS
why are fluid, electrolytes, and acid-base balance often addressed together
IMBALANCES OF ONE TEND TO INVOLVE IMBALANCES IN THE OTHERS
