Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
|
Osmosis
|
movement of water across semi-permeable membrane
less solutes & greater [H20] --> greater solutes & less [H20] as water moves across membrane generates osmotic pressure, which is pressure needed to oppose movement of H20 across membrane |
|
|
Diffusion
|
movement of charged/uncharged particles along concentration gradient
[higher] --> [lower] |
|
|
Edema
|
palpable swelling produced by expansion of interstitial fluid volume
evident @ increase of 2.5 to 3L contribute to Edema: (1) increase capillary filtration pressure --> increase movement of vascular fluid into interstitial spaces (2) decrease in capillary collodial osmotic pressure- decreased plasma proteins --> no force to pull fluid back into capillaries from spaces (3) increase capillary permeability (4) obstruction of lymph flow Manifestations: --effects determined by location --tissue level- increases distance for diffusion of O2, nutrients & wastes --susceptible to injury, ischemic tissue damage, compress blood vesels, disfiguring Assessment: daily weight, visual, measurement of affected part, pitting edema Treatment: mantaining life when involves vital structures, correcting/controlling cause, preventing tissue injury diuretic therapy, elastic stockings |
|
|
Third Spacing
|
loss/trapping of ECF in transcellular space; serous cavities
obstruction causes accumulation; contribute to body weight but not fluid reserve/function |
|
|
Regulation of Sodium
|
most sodium in ECF (135-145)
regulates extracellular fluid volume, osmotic activity, maintaining acid-base balance, current-carrying ion, contributes to NS fxn enters through GI & eliminated by kidneys (regulates Na output) |
|
|
Disorders of Thirst
|
Hypodipsia- decrease in ability to sense thirst
Polydipsia- excessive thirst |
|
|
Hypodipsia
|
decreased ability to sense thirst
inability to perceive & respond to thirst associated w/ lesions in hypothalamus |
|
|
Polydipsia
|
excessive thirst
categories: (1) symptomatic thirst- loss body water & resolves after loss replaced causes: water loss from diarrhea, vomitting, DM, DI (2) Inappropriate/Excessive thirst- persists despite hydration; cause unclear causes: renal failure, CHF (3)Psychogenic polydipsia- compulsive water drinking psychiatric disorders (schizophrenia) excessive water ingestion & impaired exrcretion --> H20 intoxication treatment: water restriction behavioral measures to decrease H2O consumption |
|
|
Disorders of ADH
|
SIADH (Syndrome of Inappropriate secretion of ADH)- ADH secretion continues when serum osmolality decreased
DI (Diabetes Insipidus)- deficiency/decreased response to ADH |
|
|
DI
|
Diabetes Insipidus
deficiency/decreased response to ADH unable to concentrate urine during water restriction excessive thirst; problem when unable to communicate thirst/secure needed H2O (1) Neurogenic/Central DI- defect in synthesis of ADH (2) Nephrogenic DI- kidneys dont respond to ADH impaired urine-concentrating ability of kidney & free water conservation Manifestations: polyuria, intense thirst, hypernatremia, dehydratoin Management: many people maintain near normal H20 balance; pharmacologic preparations (thiazide diuretics) |
|
|
SIADH
|
syndrome of inappropriate secretion of ADH
failure of negative feedback system regulating release/inhibition of ADH --> ADH secretion continues during decreased serum osmolality --> retention & dilutional hyponatremia (sodium depletion & water intoxication) transient or chronic condition Manifestations: urine output decreases, urine osmolality high & serum osmolality low, hematocrit & BUN decreased Treatment: mild- fluid restriction; diuretics, lithium; severe- hypertonic sodium chloride IV |
|
|
Regulation of Body Water
|
60% body water in adults
requires 100ml water per 100 cal metabolized for dissolving/eliminating metabolic wastes gain- oral intake & metabolism of nutrients absorbed in GI & loss through kidneys, GI tract, skin & respiratory tract kidneys- regulate volume & [solute] of ECF |
|
|
Disorders of Sodium & H2O balance
|
Isotonic Fluid Volume Deficit- decrease in ECF proportionally of sodium & H20
Isotonic Fluid Volume Excess- isotonic expansion of ECF Hyponatremia- serum sodium below 135 mEq/L Hypernatremia- serum sodium above 145 |
|
|
Isotonic fluid volume deficit
|
decrease in ECF & circulating blood volume
proportionate loss of Na & H2O Mild loss: 2%; Moderate: 5%; Severe: >8% Cause: loss of body fluids & decrease in fluid intake loss of GI fluids, third-space losses Manifestations: Signs of Compensatory Mechanisms: thirst, increased ADH (oliguria, high urine specific gravity) Decreased Interstitial fluid volume: decreased skin/tissue turgor, dry mucous membranes, sunken/soft eyeballs Decreased Vascular Volume: hypertension, weak & rapid pulse, decreased venous return, hypotension & shock Diagnosis- history of conditions predisposing to fluid & Na loss, weight loss, I&O, altered physiologic fxn Treatment: fluid replacement (isotonic electrolyte solutions), correct underlying cause |
|
|
Isotonic fluid volume excess
|
isotonic expansion of ECF & increase in interstitial & vascular volumes
usually result of disease condition Cause: decrease in Ha & H2O elimination by kidneys (disorders of renal fxn, liver failure, heart failure & corticosteriod hormone excess) Manifestations: Edema Increased Vascular Volume: full/bounding pulse, venous distention, pulmonary edema (SOB, crackles, dyspnea, cough) Diagnosis: history of disease, weight gain, edema & cardio symptoms Treatment: balance between Na I&O (sodium-restricted diet, diuretic therapy) |
|
|
Hyponatremia
|
serum sodium below 135 mEq/L; decreased osmolality, dilutional increase in blood components (hematocrit, BUN)
most common electrolyte disorder Hypertonic Hyponatremia- shift of H2O from ICF to ECF Hypotonic Hyponatremia- water retention ---Hypovolemic- less water lost w/ sodium Causes: excessive sweating, water used to replace fluids, loss of Na from GI tract from GI distilled H2o Irrigations ---Euvolemic- retention of H2O w/ dilution of Na; ECF in normal range ---Hypervolemic- edema-associated disorders: heart failure, cirrhosis, renal diseases Manifestations: Muscle: cramps, weakness, depressed deep tendon reflexes CNS: headache, disorientation, lethargy, seizures & coma GI: anorexia, nausea, vomiting, cramps, diarrhea Treatment: underlying cause H2O & Na restrictions, loop diuretic, oral/IV saline solution |
|
|
Hypernatremia
|
serum sodium above 145 mEq/L
increased osmolality, increased [blood component] (hematocrit, BUN) deficit of water in relation to Na, causes cellular dehydration Causes: net gain of Na/loss of H2O; watery diarrhea, osmotically active tube feedings with low H2O Manifestations: Compensatory: thirst, increased ADH (oliguria, high urine specific gravity) Decreased Intracellular Fluid: dry skin/mucous membranes, decreased turgor, decreased salivation & lacrimation Hyperosmolality & movement of H2O out of neural tissue: headache, disorientation, agitatin, decreased reflexes, seizures & coma Decreased Vascular Volume: weak & rapid pulse, fever, decreased BP, vascular collapse Treatment: treat underlying cause, fluid replacement |
|
|
Regulation of Potassium Balance
|
almost all in ICF
intake from diet [ECF] 3.5 to 4.5 mEq/L kidney elimination; distal collecting tubule for elimination to fine-tune [ECF] excess temporarilly shifeted into RBCs & cells of muscle, liver & bone- movement controlled by Na+/K+ pump |
|
|
Disorders of Potassium Balance
|
Hypokalemia- serum K below 3.5 mEq/L
Hyperkalemia- serum K above 5.0 |
|
|
Hypokalemia
|
serum K below 3.5 mEq/L
Causes: inadequate intake from diet excessive losses through kidney, skin & GI tract (diuretic use, metabolic alkalosis, magnesium depletion, trauma, stress, incrseased aldosterone) redistribution b/t ICF & ECF (B-adrenergic agonist drugs, insulin) Manifestations: GI: anorexia, nausea, vomiting, distention, paralytic ileus Neuromuscular: weakness, flabbiness, fatigue, cramps, tenderness, paresthesias, paralysis CNS: confusion, depression Cardio: hypotension, predisposition to digitalis toxicity, ECG changes, arrhythmias Acid-Base: metabolic alkalosis Treatment: increase intake in foods high in K+, oral supplements, magnesium if magnesium deficiency also |
|
|
Hyperkalemia
|
serum K above 5.0 mEq/L
seldom occurs in healthy person Causes: decreased renal elimination (renal failure) excessively rapid administration (oral/IV) movement of K from ICF to ECF (tissue injury, seizures, extreme exercise) Manifestations: GI: nausea, vomiting, cramps, diarrhea Neuromuscular: weakness, dizziness, cramps, parethesias, paralysis *Cardio: ECG changes, risk of cardiac arrest Treatment: decrease/curtailing intake/absorption (restricting dietary sources) |
|
|
Regulation of Calcium
|
99% in bone (strength & stability, exchange source to maintain EC Ca levels)
EC calcium- protein bound, complexed & ionized enters body through GI, absorbed in intestine under influence of Vit D, stored in bone & excreted by kidneys kidneys- fintered by glomerulus & selectively reabsorbed into blood serum calcium- fxn of Ca- regulated by PTH & Vit D, influenced by serum phosphate levels (Ca falls when phosphate high) |
|
|
Disorders of Calcium balance
|
Hypocalcemia- serum Ca below 8.5 mEq/L
Hypercalcemia- serum Ca above 10.5 mEq/L |
|
|
Hypocalcemia
|
serum Ca below 8.5
Causes: abnormal losses of Ca from kidney (renal failure) impaired ability to mobilize Ca bone stores (caused by decreased PTH, which is influenced by magnesium) increased protein binding so greater proportion of Ca nonionized pancreatitis- removes Ca from circulation Manifestations: acute/chronic Neural & Muscle Effects (Increased Excitability): parethesias, cramps, abdominal spasms & cramps, hyperactive reflexes, carpopedal spasm, tetany, laryngeal spasm Caridio: hypotension, cardiac insufficiency, decreased response to drugs acting by Ca-mechanisms, prolongation of QT interval Skeletal Effects (CHronic): osteomalacia, bone pain Diagnosis: Chvostek's sign- facial nerve spasm; Trousseau's sign- carpal spasm Treatment: Acute- emergency; IV Ca Chronic- oral intake of Ca |
|
|
Hypercalcemia
|
serum Ca above 10.5 mEq/L
Causes: Ca movement into circulation overwhelmes ability of kidney to remove Ca or regulatory hormones; increased bone resorption (neoplasms) prolonged immobilization, increased intestinal absorption, excessive Vit D, drugs (litium) Manifestations: Can't concentrate urine & exposure of kidney to increased calcium: polyuria, thirst, flank pain, sings of renal insufficiency, kidney stones Neural & Muscle (Decreased Excitability): weakness, ataxia, loss of tone, lethargy, personality/behavior change, stupor, coma Cardio: hypertension, short QT, AV block GI: anorexia, nausea, vomiting, constipation Treatment: rehydration & increase urinary excretion of Ca & inhibit release of Ca from bone diuretics, sodium chloride, fluid replacement |
|
|
Regulation of Magnesium
|
1/2 stored in bone & 1/4 - 1/2 in cells; remaining 2% in ECF
normally [serum] 1.8 to 2.7 mEq/L cofactor in IC enzyme rxns, essential to all rxns that require ATP, replication & transcription of DNA, cellulary energy metabolism, nerve conduction & membrance fxn ingested in diet, absorbed in intestine & secreted by kidneys kidney- regulates; most reabsorbed in thick loop of Henle; distal tubule major site of Mg regulation absorption decreased w/ increased serum levels, stimulated by PTH, inhibited by increased Ca |
|
|
Disorders of Magnesium Balance
|
Hypomagnesemia- serum Mg below 1.8 mEq/L
Hypermagnesemia- serum Mg above 2.7 mEq/L |
|
|
Hypomagnesemia
|
serum Mg below 1.8mEq/L
Causes: conditions limit intake/increase intentional/renal losses common finding in ER & critical care Causes: insufficient intake, excessive losses, movement b/t ECF & ICF decrease absorption- diarrhea, malabsortion syndromes, prolonged NG suction kidneys less able to conserve Mg- diabetic ketoacidosis, hyperparathyroidism, hyperaldosteronism Manifestations: Neural & Muscle: personality changes, athetoid/choreiform movements, tetany Cardio: tachycardia, hypertension, arrythmias Treatment: Mg replacement (parenteral), must be continued for several days |
|
|
Hypermagnesemia
|
serum Mg above 2.7 mEq/L
rare Causes: renal insufficiency, excess of Mg containing meds Manifestations: Neural & Muscle: lethargy, hyporeflexia, confusion, coma Cardio: Hypotension, arrythmias, cardiac arrest Treatment: alleviating renal insufficiency, avoiding Mg containing meds |
