Test 1 (12, 17, 28, 29, 31) Flashcards
Homeostasis
The state of equilibrium in the internal environment of the body.
Intracellular space
inside the cells; constitutes approx. 40% of body weight of an adult
extracellular space
outside the cells; consists of interstitial fluid, composed of the fluid in the interstitium (space between cells) and fluid contained within specialized cavities of the body (cerebrospinal fluid; fluid in the GI tract; and pleural, synovial, peritoneal, intraocular, and pericardial fluid.)
anion
ion that carries a negative charge (examples are bicarbonate (HCO3), chloride (CL) and phosphate (PO4)
cation
ion that carries a positive charge (examples are sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg)
electrolyte
substance that dissociates in solution into ions (charged particles); a molecule of sodium chloride (NaCl) in a solution becomes Na+ and Cl-
monovalent
an ion that has the combining power of one hydrogen atom
nonelectrolyte
substance that dows not dissociate into ions in solution; examples include glocose and urea
osmolality
a measure of the total solute concentration per kilogram of solvent
osmolarity
a measure of the total solute concentration per liter of solution
solute
substance that is dissolved in a solvent
solution
homogeneous mixture of solutes dissolved in a solvent
solvent
substance that is capable of dissolving a solute (liquid or gas)
valence
the degree of combining power of an ion
diffusion
the movement of molecules from an area of high concentration to one of low concentration. it occurs in liquids, gases and solids.
facilitated diffusion
moves molecules from an area of high concentration to one of low concentration with assistance from a specific carrier molecule. Glucose transport into the cell is an example.
active transport
a process in which molecules move against the concentration gradient. external energy is required for this process. By active transport, sodium moves out of the cell and potassium moves into the cell to maintin this concentration difference, also refered to as the sodium-potassium pump. the energy source for this mechanism is adenosine triphosphate (ATP), which is produced in teh cell’s mitochondria.
osmosis
the movement of water between two compartments separated by a semipermeable membrane ( a membrane permeable to water but not to a solute).
osmotic pressure
the amount of pressure required to stop the osmotic flow of water
osmolality
measures the osmotic fouce of solute per unit of weight of solvent (mOsm/kg or mmol/kg)
osmolarity
measures the total milliosmoles of solute per unit of total volume of solution (mOsm/L)
plasma osmolality
measurement of the water balance of the body. Normal is 275 - 295 mOsm/kg
water deficit
a plasma value greater than 295 mOsm/kg indicates that the concentration of particles is too great or that the water content is too little. (hypertonic solution results in cellular shrinkage)
water excess
a plasma value less than 275 mOsm/kg indicates too little solute for the amout of wter or too much water for the amount of solute. (hypotonic solution results in cellular swelling)
isotonic
fluids with the same osmolality as the cell interior
hypotonic
solutions in whihc the solutes are less concentrated than the cells
hypertonic
those with solutes more concentrated than cells
hydrostatic pressure
the force within a fluid compartment
oncotic pressure (colloidal osmotic pressure)
osmotic pressure exerted by colloids in a solution. major colloid in the vascular system contributing to the total osmotic pressure is protein. Protein molecules attract water, pulling fluid from teh tissue space to the vascular space.
fluid spacing
term used to describe the distribution of body water
first spacing
describes teh normal distribution of fluid in the ICF and ECF compartments
second spacing
refers to an abnormal accumulation of interstitial fluid (i.e. edema)
third spacing
occurs when the fluid accumulates in a portion of the body (transcellular fluid) from which is not easily exchanged with the rest of the ECF. thrid spaced fluid is trapped and unavailable for functional use. examples are ascites, sequestration of fluid in the abdominal cavity with peritonitis and edema associated with burns, trauma or sepsis.
polydypsia
excessive thirst
insensible water loss
invisible vaporization from the lungs and skin
hypovolemia
ECF volume deficit. can occur wth abnormal loss of body fluids (i.e. diarrhea, fistula drainage, hemorrhage, ployuria), inadequate intake or a shift of fluid from plasma into interstitial fluid.
hypervolemia
ECF volume excess
dehydration
refers to the loss of pure water alone without corresponding loss of sodium.
bicarbonate (HCO3) normal value
22-26 mEq/L
Chloride (Cl) normal value
96-106 mEq?l
phosphate (PO4) normal value
2.4 - 4.4 mg/dL
Potassium (K) normal value
3.5 - 5.0 mEq/L
Magnesium (Mg) normal value
1.5 - 2.5 mEq/L
Sodium (Na) normal value
135 - 145 mEq/L
Calcium (Ca) normal value
8.6 - 10.2 mg/dL
Calcium (ionized) normal value
4.6 - 5.3 mg/dL
acidosis
pH below 7.35
alkalosis
pH greater than 7.45
buffer
act chemically to change strong acids into weaker acids or to bind acids to neutralize their effect
central venous access devices (CVADs)
catheters that are placed in large blood vessels of people who require frequent access to the vascular system
abstinence
avoidance of substance in use
addiction
compulsive, uncontrollable dependence on a substance, behavior, or practice to such a degree that cessation causes severe emotional, mental, or physiologic reactions
addictive behavior
behavior associated with maintaining an addiction
craving
subjective need for a substance, usually experienced after decreased use or abstinence. Cue-induced craving occurs in the prescence of experiences previously associated with drug taking
Dependence
reliance on a substance that has reached the level that absence of it will cause an impairment in function
physical dependence
altered physiologic state from prolonged substance use; regular use is necessary to prevent withdrawal
psychologic dependence
compulsive need to experience pleasureable response from teh substance
overdose
ingestion of excessive dose of one drug or when a combination of similarly acting drugs is used. Leads to toxic reactions including respiratory and circulatory arrest.
relapse
return to substance use after a period of abstinence.
substance abuse
overindulgence of a substance that has a negative impact on psychologic, physiologic, and/or social functioning of an individual
substance misuse
use of a drug for purposes other than those for which it is intended.
tolerance
decreased effect of a substance that results from repeated exposure. It is possible to develop cross-tolerance to other substances in teh same category.
withdrawal
combination or physiologic and psychologic responses that occur when there is abrupt cessation or reduced intake of a substance on which an individual is dependent.
Wernicke’s encephalopathy
an inflammatory, hemorrhagic, degenerative condition of the brain. a serious complication of chronic alcohol abuse caused by thiamine deficiency resulting from poor diet and alcohol-induced suppression of thiamine absorption. reversible with administration of thiamine.
korsakoff’s psychosis
an irreversible form of amnesia characterized by loss of short-term memory and an inability to learn.
anemia
a deficiency in the number of erythrocytes (red blood cells), the quantity of hemoglobin, and/or the volume of packed RBCs (hematocrit)
anemia from decreased RBC production
deficient nutrients: iron, cobalamin, folic acid; decreased erythropoietin, decreased iron availability
anemia from blood loss
Chroni hemorrhage: bleeding duodenal ulcer, colorectal cancer, liver disease, acute trauma, ruptured aortic aneurysm, GI bleeding
