ch 42 potter fluid, electrolyte, acid-base Flashcards
electrolytes such as sodium and potassium and also have a degree of acidity.
Cellular fluids contain
balances within the body maintain the health and function of all body systems.
Fluid, electrolyte, and acid-base
fluid amount (volume), concentration (osmolality), composition (electrolyte concentration), and degree of acidity (pH).
characteristics of body fluids influence body system function because of their effects on cell function
means water that contains dissolved or suspended substances such as glucose, mineral salts, and proteins.
fluid
have less water in their bodies than people who are lean because fat contains less water than muscle
People who are obese
extracellular fluid (ECF)outside the cells and intracellular fluid (ICF)inside the cells
Body fluids are located in two distinct compartments:
is approximately two-thirds of total body water.
adults ICF
approximately one-third of total body water
adults ECF
(intravascular fluid and interstitial fluid)and a minor division (transcellular fluids).
ECF has two major divisions
is the liquid part of the blood (i.e., the plasma)
Intravascular fluid (ECF)
is located between the cells and outside the blood vessels.
Interstitial fluid (ECF)
such as cerebrospinal, pleural, peritoneal, and synovial fluids are secreted by epithelial cells
Transcellular fluid (ECF minor division)
is a compound that separates into ions (charged particles) when it dissolves in water
electrolyte
sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium ions (Mg2+).
Cations in body fluids are
chloride (Cl − ) and bicarbonate (HCO3–)
Anions in body fluids are
salts
Anions and cations combine to make
of a fluid is a measure of the number of particles per kilogram of water.
.Osmolality
fluid with the same tonicity as normal blood is called
isotonic
solution is more dilute than the blood
hypotonics
solution is more concentrated than normal blood
hypertonic
processes that move water and electrolytes between body compartments.
Active transport, diffusion, osmosis, and filtration are
requires energy in the form of adenosine triphosphate (ATP) to move electrolytes across cell membranes against the concentration gradient (from areas of lower concentration to areas of higher concentration).
Active transport
is passive movement of electrolytes or other particles down a concentration gradient (from areas of higher concentration to areas of lower concentration).
-diffusion of electrolytes across cell membranes requires proteins that serve as ion channels.
Diffusion
Water moves across cell membranes by osmosis,a process by which water moves through a membrane that separates fluids with different particle concentrations
osmosis
interstitial fluid from ICF
semipermeable cell membranes separate
, an inward-pulling force caused by particles in the fluid.
osmotic pressure
Fluid moves into and out of capillaries (between the vascular and interstitial compartments) by the process of
filtration
is the net effect of four forces, two that tend to move fluid out of capillaries and small venules and two that tend to move fluid back into them.
Filtration
is the force of the fluid pressing outward against a surface
Hydrostatic pressure
Blood contains albumin and other proteins known as
colloids
Blood colloid osmotic pressure, also called oncotic pressure, is an inward-pulling force caused by blood proteins that helps move fluid from the interstitial area back into capillaries.
oncotic pressure
is strongest at the arterial end of a normal capillary
Capillary hydrostatic pressure
is weaker, and the colloid osmotic pressure of the blood is stronger.
venous end capillary hydrostatic pressure
Disease processes and other factors that alter these forces may cause accumulation of excess fluid in the interstitial space, known
asedema
Inflammation is another
cause of edema
fluid intake and absorption, fluid distribution, and fluid output
Fluid homeostasis is the dynamic interplay of three processes:
is located within the hypothalamus in the brain
thirst-control mechanism
is located within the hypothalamus in the brain
thirst-control mechanism
: the skin, lungs, gastrointestinal (GI) tract, and kidneys.
Fluid output normally occurs through four organs
synthesized by neurons in the hypothalamus that release it from the posterior pituitary gland
ADH
volume imbalances and osmolality imbalances
two major types of fluid imbalances:
means decreased vascular volume
-occurs ECV deficit
hypovolemia
—Water and Sodium Lost or Gained in Equal or Isotonic Proportions
Isotonic Imbalances
—Body Fluids Have Decreased Volume but Normal Osmolality
Extracellular Fluid Volume Deficit
increased osmolality (too concentrated) -water deficit
Hypernatremia
loss of relatively more water than salt or gain of relatively more salt than water
Two general causes make body fluids too concentrated:
are those of cerebral dysfunction, which arise when brain cells shrivel. Hypernatremia may occur in combination with ECV deficit; this combined disorder is called clinical dehydration.
Signs and symptoms of hypernatremia
also called water excess or water intoxication,is a hypotonic condition.
Hyponatremia,
excessively dilute condition of interstitial fluid causes water to enter cells by osmosis, causing the cells to swell
Hyponatremia,
Signs and symptoms of cerebral dysfunction occur when brain cells swell
Hyponatremia,
ECV deficit and hypernatremia often occur at the same time; this combination is called
clinical dehydration
gastroenteritis or other causes of severe vomiting and diarrhea when people are unable to replace their fluid output with enough intake of dilute sodium-containing fluids.
Clinical dehydration is common with
shifts Ca2+out of bone;
Parathyroid hormone
shifts Ca2+into bone.
calcitonin
Electrolyte intake less than electrolyte output or shift of electrolyte from the ECF into cells or bone causes
plasma electrolyte deficit
Electrolyte intake greater than electrolyte output or a shift of electrolytes from cells or bone into the ECF causes
plasma electrolyte excess.
abnormally low potassium concentration in the blood
Hypokalemiais
results from decreased potassium intake and absorption, a shift of potassium from the ECF into cells, and an increased potassium output
Hypokalemiais
diarrhea, repeated vomiting, and use of potassium-wasting diuretics
- muscle weakness
- cardiac dysrhythmias
Common causes of hypokalemia
physiologically active form of calcium in the blood is
ionized calcium.
Factors that cause too much ionized calcium to shift to the bound forms cause symptomatic
ionized hypocalcemia
hypocalcemia because calcium binds to undigested fat in their feces and is excreted.
acute pancreatitis frequently develop
results from increased calcium intake and absorption, shift of calcium from bones into the ECF, and decreased calcium output
Hypercalcemia
abnormally high calcium concentration in the blood.
Hypercalcemiais