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89 Cards in this Set
- Front
- Back
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how much water are in females, males?
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50%, 60% due to more fat in females;
Rule: more fat less water in body more mm. more water in body |
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where are extracellular fluids found?
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- anywhere outside cell, lymph, interstitium, plasma, pericardial, pleural, peritoneal cavities
- makes 1/3 total body fluids - intracellular makesup 2/3 total body fluids |
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what are some electrolytes?
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- inorganic salts
- inorganic and organic acids & bases - they have a charge |
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what are some non-electrolytes?
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- glucose
- creatinine - lipids basically molecs that hold no charge |
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what determines osmotic activity?
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- dissolve solutes
but rem electrolytes are disporportionate bc they can breakdwn into 2 or more ions |
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what unit used to express electrolyte conc?
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- milliequivalents/L
mEq/L |
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what determines movement of fluids btw compartments?
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- hydrostatic and osmotic pressure & water moves according to gradient but solutes are unequally distributed
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why are solutes unequally distributed?
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- due to the differences in their membrane permeability
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what are most common ions fnd in extracellular fluids?
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- Na+
- Ca2+ - Cl- - HCO3-(bicarbonate) |
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most common ions fnd in intracellular fluids?
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- K+
- Mg2+ - HPO42- (phosphate) |
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what fluid is best monitored? how?
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- ECF
- receptors will monitor osmotic conc.(basically amt of water amongst solutes) & plasma vol. - osmotic gradient monitors water |
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how much water is lost thru urine, skin, lungs, fecal matter?
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- urine 1200-1500 mL
- lungs 400 mL - skin 250 mL - fecal 150 mL |
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what are other ways body losses water?
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- thru increased activity & body temp
- fever |
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how does the body gain fluid?
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- drinking
- eating - body just producing water as byproduct of metabolic rxns |
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what happens in dehydration when loss exceeds gain?
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- loss of water w/o electrolytes causes ECF to become hypertonic so fluid fm ICF moves out to ECF
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what happens if loss still conts after ICF fluid has moved to ECF?
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- drop in plasma vol
- circulatory shock poss - hypernatremia |
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what occurs when gains exceed losses?
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- ECF becomes hypotonic so fluid moves into ICF 1st attempt to balance therefore
- ICF vol increases - homeostatic resp where there's drop in ADH and fluid intake |
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what happens if mvmt of fluid fm ECF to ICF, and homeostatic response doesnt work?
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- over hydration and poss swelling of brain cells and hyponatremia
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what system interactions are important in regulating blood volume and ultimately bp?
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- kidney(renal system) & circulatory system bal Na+ and fluid reabsorption
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how much and where is Na normally reabsorbed?
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- PCT 65%
- ascending Loop of Henle 27% |
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what is needed to absorb when necessary more Na? where will it be reabsorbed?
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- DCT
- collecting ducts depending on presence of aldosterone |
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describe aldosterone
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- made in adrenal cortex w/in zona glomerulosa
- is a mineralcorticoid - reabsorbs Na fm DCT, collecting ducts, and thru epithelial cells of sweat glands, salivary glands and GI mucosa - at same time promotes K+ secretion fm DCT but increases K+ in sweat glands and saliva |
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what controls secretion of aldosterone?
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- hypothalamic-hypophyseal-adrenal cortical axis via ACTH=>CRH=>aldosterone
-hyperkalemia -hyponatremia |
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what is major mech by which aldosterone is released?
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- RAA by juxtaglomerular and macula densa cells w/in juxtaglomerular apparatus
- rem. angiotensinogen is made by liver but is converted to angiotensinogen I in kidneys by renin |
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juxtaglomerular cells release renin in response to?
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- drop in bp due to hypovolemia
- hemorrhage - salt depletion - postural hypotension |
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what are JG cells stimulated by?
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sympathetic postganglionic fibers
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what do macula densa cells do?
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- act as chemoreceptors for Na and tell JG cells to release renin if their conc. is too low
A decrease in blood pressure causes a decrease in the GFR (glomerular filtration rate) meaning less filtrate is made bc there is more reabsorption, resulting in a decreased concentration of sodium and chloride ions at the macula densa and triggers an autoregulatory response to increase reabsorption of ions and water in order to return blood pressure to normal - they also monitor speed of passing filtrate so if goes to fast will vasoconstrict afferent a. which will inc. GFR |
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what are the effects of angiotensin II
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- powerful vasoconstrictor
- stimulates secretion of aldosterone - stimulates release of ADH - stimulates thirst |
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describe atrial naturetic peptide(ANP)?
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- released fm atria in response to stretching of atria(or increased blood volume)
- antagonizes RAA system |
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what are effects of ANP?
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1- causes vasodilation of afferent arteriole and vasoconstriction of efferent arteriole = increases GFR (means more filtrate made and excreted)
2- inhibits afferent arteriole fm releasing renin 3- inhibits glomerulosa cells of adrenal cortex to release aldosterone 4- inhibits collecting duct fm Na and Cl reabsorption 5- inhibits posterior pituitary fm releasing ADH 6- inhibits ADH fm acting on collecting ducts |
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what is pressure diuresis?
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- compensator mechanism that control blood volume (and bp)- where more urine is excreted in high blood volume=high bp and less urine excreted in low bp
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explain pressure diuresis w/high blood volume=high bp?
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- overall CO will increase which will increase arterial pressure which will increase urinary output
- increase in baroreceptor activity - decrease in sympathetic activity which will dilate afferent arteriole - increase in GFR - increase release of ANP - inhibition of ADH - decrease in aldosterone - decrease in renin all lead to increase Na & fluid output fm kidneys(more urine produced) |
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explain pressure diuresis w/low blood volume=low bp
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- decrease in baroreceptor activity
- increase in sympathetic activity which will vasoconstrict afferent arteriole - decrease in GFR(so less filtrate made) - decrease release of ANP - increase release of renin which will stimulate release of ADH and aldosterone - overall there will be more fluid and Na retention |
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when does hyponatremia occur?
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- diarrhea
- vomiting - renal failure - water overload(over hydration) |
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what happens in severe hyponatremia?
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-there more water than electrolytes
- water fm plasma goes to brain cells and they begin to swell causing vomiting, nausea, HA |
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when does hypernatremia occur?
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- dehydration
- inadequate fluid intake - intake of diuretics causes lethargy, weakness and irritability |
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what regulates the resting membrane potential of all cells?
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- K+
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how is K+ reabsorbed?
how is K+ balance maintained? |
- thru PCT and loops of henle independent of hormonal presence
- thru secretion of K+ into filtrate, and to the principal cells of DCT, and collecting ducts esp when seen in high levels in blood |
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how does aldosterone affect principal cells in DCT and collecting duct?
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- allows principal cells to reabsorb Na and excrete more K+ in exchange
- adrenal cells very responsive to K+ levels in surrounding fluids |
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what are some causes of hyperkalemia?
S/S? |
- kidney disease
- some meds S/S: malaise(lethargy), - palpitations - muscle weakness |
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what are causes of hypokalemia?
S/S? |
- lack in diet
- use of diuretics S/S: - muscle weakness - severe case paralysis |
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where is Ca mostly found?
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- w/in bone mix w/phosphate
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what is Ca imp for?
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- blood clotting
- hormone response coupling - membrane permeability characteristics - also influence strength of cardiac contraction |
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what happens in hypocalcemia?
S/S ? |
- increases membrane permeablity which leads to tetanus or m. spasms
- intestinal cramps - weakened heartbeat - cardiac arrhythmias - osteoporosis |
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what are the causes of hypocalcemia?
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- hypoparathyroidism
- Vit. D deficiency - poor diet - renal failure |
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what happens in hypercalcemia?
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- inhibits n and m. activity
- cardiac arrhythmias(abnorm. electrical activity of heart) |
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what is the cause of hypercalcemia?
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- hyperparathyroidism
- too much Vit D |
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what balances Ca?
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- calcitonin: decreases blood Ca levels by adding it to bone and deactivates osteoclasts
- parathyroid hormone(PTH): increases blood Ca levels by stripping bone via osteoclasts(increases their activity) |
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when there's normal blood pH what happens to Na and Cl?
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- 99% Cl is reabsorbed passively as Na is being reabsorbed at the same time
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what is the importance of pH?
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- influences the proper fxning of enzymes
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what is pH of arterial blood?
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7.35 - 7.45
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what is pH of venous blood?
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7.35
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what is pH of interstitial fluids?
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7.35
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what is pH of intracellular fluids?
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7.0 or close to it
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what reference is used to measure pH?
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- arterial blood
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what are different types of acids w/in the body?
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- volatile acids ie carbonic acid
- fixed acids ie phosphoric acid - organic acids any byproduct of metabolic rxns ie lactic acid, ketone bodies, stomach acid |
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what are the 3 mechanisms for acid-base balance?
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- buffer systems: in blood very short lived
- respiratory system: not activated as quickly but stronger than above - kidneys: most imp for long term regulation; takes longest to activate but most potent |
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what is a buffer system?
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- are 1 or more molecs that can resist changes in pH when strong acid or base is added
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what are the types of buffer systems?
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- bicarbonate buffer system
- phosphate buffer system - proteins ie Hb |
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describe bicarbonate buffer system?
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basically its a buffer made w/carbonic acid and its weak salt: sodium bicarbonate
- 2 scenarios; 1st: HCl + NaHCO3=>H2CO3 + NaCl so when strong acid is added it becomes a weak acid 2nd: NaOH + H2CO3=>NaHCO3 + H2O so when strong base is added its converted into weak base |
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describe phosphate buffer system?
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- does same as bicarbonate buffer system
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describe how proteins act as buffers?
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- have AA that are organic acids or bases
Ex: Hb buffer works only on RBCs |
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give ex of extracellular buffers?
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- bicarbonate
- protein buffers ie AA and plasma protein buffers |
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ex of intracellular buffers?
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- phosphate buffers
- protein buffers ie AA and Hb buffer |
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describe the respiratory system as mechanism(equation) for acid-base balance
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CO2 + H2O <=> H2CO3 <=> HCO3- + H+
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describe respiratory acidosis
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- caused by increase level of CO2 (which is drop blood pH) which is picked up by central chemoreceptors which increase rate and depth of breathing so the CO2 can be blown off
- its also caused by any cond that impairs ventilation and proper gas exchange |
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where do we also see increase in rate and depth of breathing?
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-metabolic acidosis where peripheral chemoreceptors are activated but decreasing your CO2 levels won't bring pH back to normal it is the accumulation of H+ that are the problem;
so pt is also causing respiratory alkalosis as secondary prob |
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what are some causes of respiratory acidosis?
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- chronic bronchitis
- emphysema - cystic fibrosis - narcotic or barbiturate overdose - injury to brain stem which depressed activity of respiratory center |
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what happens in the recovery phase of respiratory acidosis?
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- blood pH rises
- respiratory center is depressed making breathing more shallow which will increase CO2 levels |
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how is respiratory alkalosis caused?
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due to hyperventilation seen in:
- anxiety - high elevations - asthma - pneumonia |
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what can kidneys do as far as acid/base balance?
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- based on plasma pH, can excrete H+ into urine
- reabsorb Na ions - conserve bicarbonate ions which can act as buffers |
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what are the 2 ways H+ can be reabsorbed during acidosis or when all the bicarbonates are used up?
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- phosphate buffer
H+ + HPO4- <=> H2PO4 -add H+ to ammonia& make ammonium (NH4) both of which are excreted in the urine |
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during acidosis, describe pH blood leaving kidney, and urine leaving bladder?
**NOT SURE** |
- blood is more basic
- urine more acidic? |
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during alkalosis, plasma and intracellular H+ falls (plasma alkalinic) so now enough bicarbonates are resorbed and H+ can be excreted, so describe blood leaving kidneys and urine leaving bladder
***NOT SURE*** |
- blood leaving kidneys will be acidic
- urine will be basic |
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what are some causes of metabolic acidosis?
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1- severe diarrhea bc u lose bicarbonate ions fm interstitial fluids
2- renal disease 3- untreated diabetes mellitus w/ketone body production leading to ketoacidosis 4- excess alcohol intake |
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causes of metabolic alkalosis?
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1- vomiting of gastric contents
2- ingestion of excessive soldium bicarbonate 3- selected diuretics |
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what will pH below 7.0 cause?
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- depress CNS
- coma |
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what will pH above 7.8 cause?
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- overexcites nervous system
- muscle tetany |
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what gives urine its color?
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- Hb breakdwn
- sometimes certain foods |
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what causes odor in urine?
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- ammonia
- bacterial metabolism - fruity odor indicates DM pts w/high acetone content |
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how does specific gravity relate to urine?
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- measured against distilled water
- high specific gravity occurs w/dehydration, congestive heart failure, liver failure - low specific gravity occurs w/diabetes insipidus |
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what are abnormal contents that shd not be found in urine?
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- glucose "glycosuria"
- protein esp albumin "proteinuria"/ "albuminuria" - ketones "ketonuria" - hemoglobin "hemoglobinuria" - bile pigments "bilirubinuria" - erythrocytes "hematuria" - leukocytes "pyuria" |
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cause of glycosuria?
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- DM
- high carbohydrates |
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cause of proteinuria or albuminuria?
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- high protein diet
- pregnancy - exertion - severe HTN - renal disease - glomerulonephritis |
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what is used to test kidney fxn?
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- BUN (blood urea nitrogen) test
- serum creatinine |
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describe BUN test
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- measures nitrogen in form of urea which is end product of protein metabolism
- formed in liver but excreted by kidneys - elevated levels indicate renal disease |
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describe serum creatinine test
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- non protein byproduct of creatinine metabolism
- creatinine levels directly related to GFR - elevated levels indicate renal disease |
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what is incontinence?
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- inability to control urination volunatarily
- occurs in elderly and children |
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what is urinary retention?
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- inability to urinate
- found in men w/prostatic enlargment |
