Create
Learn
Share

Obmp4

rename
robbypowell's version from 2016-06-25 21:54

Physiology: Body Fluids (Dr. Stan Lee)

Question Answer
Total body water makes up what % of body weight?60%
Intracellular fluid makes up what % of body weight?40%
Extracellular fluid (interstitial and plasma) makes up what % of body weight?20%
Interstitial fluid makes up what % of body weight?15%
Plasma makes up what % of body weight?5%
When you subtract Extracellular Fluid from Total Body water, what fluid compartment volume are you estimating?INTRAcellular fluid volume
Radio-iosinated serum albumin can be used to measure the volume of what body fluid compartment?Plasma (albumin doesn't cross the capillary walls... so only stays in plasma)
What compound can be used to measure Total Body Water (60% volume)3H2O (ionized or radio-labeled water?)
Water shifts between ECF and ICF that happen because of differences in osmolarity occur via ____Osmosis
movement of water from high concentration of water to low concentration of water across a semi-permeable membraneOsmosis
When placed in a ____-tonic solution, cell volume decreaseshypertonic
When placed in a ____-tonic solution, cell volume increaseshypotonic
When placed in a ____-tonic solution, cell volume stays the sameisotonic
Infusion of ____-tonic saline will increase extracellular fluid volume onlyISOtonic (because isotonic water does not affect the volume of cells)
T/F: Intracellular and interstitial body fluids have similar total osmotic pressuresTRUE (components and solutes are different but total osmotic pressure are similar... because this balances between the two compartments)
T/F: Intracellular and interstitial body fluids have similar potassium concentrationsFalse (major cation of INTRAcellular fluid ... so, much higher within cells than in interstitial)
T/F: Intracellular and interstitial body fluids have similar bicarbonate concentrationsFalse (higher in interstitial)
T/F: Intracellular and interstitial body fluids have similar chloride concentrationsFalse (major cation of interstitial environment)
Movement of water between the ICF and ECF compartments is mainly achieved by what process?Osmosis (passive diffusion to achieve osmotic equilibrium)
If a membrane permeable only to water has 2mg/L on side A and 1mg/L on side B... which was does the water move?toward side A (achieve osmotic equilibria)
Is Hydrostatic pressure greater at the arteriolar or venous end of capillaries?Arteriolar (drives out) (Venous is lower, allowing back in)
What pressure opposes fluid loss from capillaries?Oncotic pressure (of the greater protein concentration in plasma)
What Starling Equation pressure is caused exclusively by plasma proteins, mainly albumin, because these are the only molecules not in diffusion equilibrium across the capillary wall?ONCOTIC pressure (aka Colloid pressure)
What is the primary plasma protein that contributes to oncotic (colloid) pressure?Albumin
Less plasma proteins in the body cause fluid to shift how?more into the interstitial fluid compartment (and out of capillaries) (decreased oncotic pressure is cause)
More plasma proteins in the body cause fluid to shift how?more in the capillaries (plasma compartment) and less in the interstitial fluid compartment (increased ONCOTIC pressure is cause)
T/F: Osmotic pressure is different for 1 M glucose and 1 M NaClTrue (this is because NaCl disocciates, creating 2 M total... 1 M Na+ and 1 M Cl-)
T/F: Osmotic pressure is the same for 1 M glucose and 1 M NaClFalse (this is because NaCl disocciates, creating 2 M total... 1 M Na+ and 1 M Cl-.... glucose remains 1 M glucose in solution)
Fluid normally leaves capillaries at arteriolar end and re-enters at venous end... this is because of a difference of what Starling Equation pressure?Plasma Hydrostatic Pressure (lower on venous end)
What is the "most important function" of the Lymphatic system?Return of plasma proteins in the interstitial fluid back to the blood
Lymph composition is virtually identical to that of what ______ fluidInterstitial fluid (this is source of lymph fluid, and its route to return plasma proteins to blood)
What are the 2 "major lymph ducts"?Thoracic duct and Right Lymph duct
_____ is defined as a state with excess fluid volume in interstitial compartmentEdema
A decrease in Plasma oncotic pressure has what, if any, effect on Lymph flow?INCREASE in lymph flow (more fluid moves into interstitial, so more fluid moves through lymph)
What duct transports lymph from the abdominal region?Thoracic duct
What duct transports lymph from the right head, neck and arm?Right Lymphatic duct
What duct transports lymph from the left head, neck and arm?Thoracic duct
What is the "functional unit" of the kidney?Nephron (composed of the glomerulus, proximal and distal tubules (in cortex), loops of Henle and collecting ducts (in medulla))
define: the rate (mL/minute) at which plasma is filtered through the glomerular capillaries into the renal tubulesGlomerular filtration rate (GFR)
What is the average Glomerular Filtration Rate?125mL/min
What is the major determinant of GFR?blood pressure
Clearance of _____ gives an indication of Glomerular Filtartion RateINULIN (not urea... urea is excreted not filtered)
What factor most influences the renal clearance of fluoride?acidity of the renal tubular fluid
If a substance is freely filtered through the glomeruli, but not reabsorbed or secreted, its renal clearance is a measure of what?Glomerular Filtration Rate (e.g. Inulin)
In the absence of compensatory changes, constriction of the efferent arteriole (without constriction of afferent arteriole) would have what effect on GFR?INCREASE GFR
In the absence of compensatory changes, dilation of the efferent arteriole (without dilation of afferent arteriole) would have what effect on GFR?DECREASE GFR
Most of filtrate is reabsorbed where in nephron?proximal tubule
glucose, bicarbonate (CA) and potassium are almost entirely reabsorbed in what part of the nephron?Proximal tubule
If a substance is freely filtered through the glomeruli, extensively secreted but not reabsorbed its clearance could be used to measure what?renal plasma flow rate (e.g. p-Amminohippuric Acid)(aka PAH)
maximum amount of a given substance that can be reabsorbed (or secreted) per unit time (in nephron)tubular maximum transport (Tm)
when the amount of glucose filtered is greater than Tm... what happens?glucose is excreted in the urine
Why does glucose filtration greater than Tm result in polyuria?Because when glucose can't be reabsorbed osmotic pressure in tubular fluid draws more water along with the glucose (as it would for any excess solute)
GFR/Renal Plasma flow = _________ fractionFiltration fraction
Renal blood flow/Cardiac output = ______ fractionRenal fraction
The presence of glucose in the urine indicates what?filtered more glucose than can be reabsorbed (aka filtration exceeded Tm Glucose)
Carbonic anhydrase is important in the renal absorption for what?Bicarbonate (HCO3-)
T/F: Any substance that is actively secreted into the renal tubules cannot be used to measure Glomerular Filtration RateTrue
T/F: Any substance that is actively secreted into the renal tubules can be used to measure Glomerular Filtration RateFALSE (GFR only meant to measure filtration... anything excreted or absorbed would misrepresent GFR)
What hormone that is secreted by kidneys stimulates RBC production?Erythropoietin
What hormone that is secreted by adrenal cortex promotes sodium reabsorption in exchange for potassium and hydrogen ions in the distal nephron?Aldosterone
Aldosterone promotes _____ reabsorptionSodium
Aldosterone promotes sodium reabsorption in exchange for___ and ___ ions in what part of the nephron?Potassium (K+) and Hydrogen (H+) Ions; in the distal nephron
What hormone that is secreted by posterior pituitary opens water channels in distal tubule and collecting duct so that, when ADH is available, water is reabsorbed?Vasopressin (aka Anti-Diuretic Hormone aka ADH)
(increase/decrease) of ADH would result in diabetes insipidus?Decrease (less water is reabsorbed, so polyuria)
Which has greater osmolarity... urine or plasma?urine (concentrated)
Concentration of urine is dependent on ADH (which reabsorbs water) and ____-tonic medullary interstitial fluidHYPERTONIC medullary interstitial fluid (draws water out via osmotic pressure)
Which part of the nephron is impermeable to water and actively reabsorbs sodium and chloride?Thick Ascending Limb of Loop of Henle
The main effect of ____ is to cause increased reabsorption of sodium in the distal tubule and collecting ductAldosterone
____ acts to increase water reabsorption from the distal tubule and collecting ductADH (Anti-diuretic hormone, aka Vasopressin)
The countercurrent multiplier system is important in the formation of urine with a higher osmolarity than plasmaTrue
The countercurrent multiplier system is important in the formation of urine with a lower osmolarity than plasmaFalse (higher than plasma... bc its concentrated)
T/F: The countercurrent multiplier system is dependent on the action of ADHFalse (ADH acts after loop of henle... where countercurrent multiplier system is)(unrelated)
T/F: The countercurrent multiplier system is dependent on water reabsorption in the distal nephronFalse
T/F: The countercurrent multiplier system is dependent on active reabsorption of sodium/chloride in the ascending limb of Henleā€™s loopTrue... (this is how it functions... its purpose is to create a Medullary Hypertonic interstitial fluid relative to tubular fluid)
How is hypertonicity of medullary interstitial fluid (relative to tubular fluid) achieved?active reabsorption of Na and Cl (in thick ascending loop of henle) without allowing water to follow
What is the normal blood pH?7.4
What is the henderson-hasselbach equation?pH = pK + log (salt/acid) (HCO3-/H2CO3)
2 Most important buffers in urinePhosphate and Ammonium (b/c almost all bicarb has been reabsorbed)
T/F: Lungs control pH of the bodyTrue (by controlling CO2 and thus HCO3- concentration)
T/F: Kidneys control pH of the bodyTrue (by excreting H+ and reabsorbing HCO3-)
According to the ________ equation, the pH of a buffer system depends on the pK of the weak acid and the ratio of the concentrations of the salt and weak acidHenderson-Hasselbach equation
according to Henderson-Hasselbach equation... when does pH equal pK?when acid/conjugate base concentrations are equal
Acidosis can be cause by _____ (increased/decreased) breathing rateDecreased (buildup of CO2 causes acidosis)
Alkalosis can be caused by _____ (increased/decreased) breathing rateIncreased (decline in CO2 causes alkalosis)
activity of the respiratory center is controlled directly by what factor?blood pH
activity of the respiratory center is increased directly by ______ pHdecreased pH (more acidic blood)
activity of the respiratory center is decreased directly by ______ pHincreased ph (more basic blood)
Renal compensation for chronic metabolic acidosis involves maximum reabsorption and creation of "new" what...?Bicarb
The Sympathetic Nervous system (inhibits/stimulates) smooth muscle motilityInhibit
The Parasympathetic Nervous system (inhibits/stimulates) smooth muscle motilityStimulates
The Enteric system has two nerve plexuses: ______ plexus controls mixing and propulsive movements, while _____ plexus controls secretion and blood flowMyenteric (Auerbach's) plexus; Submucosal (Meissner's) plexus
______ (hormone) stimulates stomach/small intestine motility, acid secretion and relaxes the ileocecal sphincterGastrin
_____ (hormone) slows gastric emptying (role of fat)Cholecystokinin
Stimulation of the sympathetic nervous supply to the GI tract generally causes what result?Decreased motility
Ingestion of what has the greatest effect on gastric emptying?fats
Stimulation of which of the enteric nerve plexuses would have the greatest effect on peristalsis?Myenteric (Auerbach's) plexus
Primary salivary secretion have composition similar to ECF... however they are modified as they travel through the ducts... what concentrations are altered?Na (lowered, reabsorbed), K+ (increased, secreted), HCO3- (increased, secreted)
What organ is the major source of digestive enzymes and HCO3-?Pancreas
What hormone causes digestive enzyme secretion from the pancreas?Cholecystokinin
What hormone causes bicarb secretion from the pancreas?Secretin
Biles is secreted by the ______ and stored in the _____Liver; Galbladder
what triggers the secretion of Cholecystokinin (CCK)?CCK secretion stimulated by FAT IN DUODENUM
CCK causes _____ constriction and relaxation of the sphincter of ____Galbladder; Oddi
What hormone causes gallbladder constriction?CCK (Cholecystokinin)
Intrinsic Factor is produced where?stomach
Intrinsic factor is essential for absorption of what?B12
An increase in salivary flow is caused by stimulation from the _______ nervous systemParasympathetic
Digestion of proteins, fats and sugars occurs by _____hydrolysis
pepsin (stomach); trypsin, chymotrypsin and carboxypolypeptidases (pancreas); are digestive enzymes that break down _______proteins
bile acids; pancreatic lipase (major) and enteric lipase (minor) are digestive enzymes that break down _____fats
Sugars are digested and absorbed as monosaccharides... they co-transport with ____Sodium (Na+)
Amino acids absorbed as di- and tripeptides and cotransport with _____sodium (Na+)
Fats absorbed via central lacteals (lymphatics) as ______chylomicrons
An important function of HCl in the stomach is the activation of what zymogen?Pepsinogen
T/F: After functioning in the small intestine, the largest portion of bile salts are reabsorbed via the portal circulation and reusedTrue
T/F: After functioning in the small intestine, the largest portion of bile salts are excreted in the feces.False (majority is reabsorbed)
Acid in the duodenum/jejunum causes secretin to be secreted which has what effect?Secretion of pancreatic Bicarb
What is the GI enzyme having a pH optimum close to 2.0?Pepsin
memorize