Term
| How many nephrons in each kidney? |
|
Definition
|
|
Term
| What part of the nephron that surrounds the capillaries? |
|
Definition
|
|
Term
| What are the three segments of the loop of henle (She wants to know their functions too.) just answer what are the three segments in order from the bowman's capsule |
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Definition
| Descending thin segment - ascending thin segment - thick segment of the ascending. |
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Term
| The nephron tubular segment starts at the ? and ends at the ? |
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Definition
| Starts at the nephron's bowman's capsule and ends at the end of the distal tubule. After the distal tubule is where the collecting ducts begin the connection between the two is a segment of the nephron known as the connecting tubule. |
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Term
| Collecting ducts of the nephron also referred to as? |
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Definition
|
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Term
| Whats the difference between the nephron tubular and collecting ducts? What do those cells do? |
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Definition
| Different types of cells. On the collecting ducts there are more principal cells and more intercalated cells. Therefore it is here where aldosterone and ADH act on the nephrons. |
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Term
| The most proximal part (segment) of the collecting duct system is called? |
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Definition
| The collecting duct. It is located at the end of the distal convoluted tubule. |
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Term
| What part of the proximal tubule helps with increasing the rate of absorption and how does that happen? |
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Definition
| micro villi increase the surface area for absorption and interaction with substances |
|
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Term
| What is a big difference between thick ascending loop of henle and thin descending loop of henle |
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Definition
| Thin descending have no micro villi but is very permeable to H20 while the thick ascending loop of henle has lots of villi which makes it very absorbant to ions but not permeable to H20 |
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Term
| what percentage of ion reabsorption is done at the ascending loop of henle? |
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Definition
|
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Term
| Explain the blood supply of the nephron |
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Definition
| Renal artery is the main supply for kidney. It branches to segmental arteries which supplies different section of the entire kidney. That then branches to interlobar arteries which travel around the renal pyramids. On top of the renal pyramids are the multiple nephrons (they look like vines on the perimeter of the kidney) which then get supplied by small branches of arteries known as arcuate arteries (those look like the hoses that run in large rows in a field) from there the smaller arteries branch off to individual interlobular arteries which then supply along the chain of glomerula to invididual afferent arteriole. |
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Term
| The juxtamedullary nephron has an extra capillary bed known as the? |
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Definition
| vasa recta which run allong the loop of henle which in the juxtamedullary nephron is completely below the cortex and in the medulla. |
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Term
| Whats a big difference between the juxtamedullary nephron and cortical nephron? |
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Definition
The cortical nephons make up 75% of the nephrons and their body is mostly in the cortex and only a small part of its loop of henry is in the medulla.
Juxtamedullary nephrons are more important in ion concentration. |
|
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Term
| What are pressures high in the glomerulra capillaries in the bowman capsule? |
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Definition
| b/c pressure needs to remain high from the afferent artery through the bowman's capsule to still be high enough to supple blood down the efferent artery to peritublar capillaries further along the nephron |
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Term
| what percentage of blood supplies the kidneys. |
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Definition
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Term
| Whats unique in the kidneys with their arteriole / capillary / venoule system? |
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Definition
| There is an arteriole (Afferent arteriole) that supplies a large capillary bundle (known as the glomerular capillaries) which then empties into anoter arteriole instead of a venoule known as the EFFERENT arteriole to more capillaries and then FINALLY into venoule. |
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Term
| At the bowman's capsule what type of mechanism is occuring? filtration/secretion/reabsorption or exretion? |
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Definition
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Term
| At what part of urine formation doe we have tubular secretion and resorption? |
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Definition
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Term
| What are the only two mechanisms to be removed from the body via the urinary system |
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Definition
1. Secretion from the peritubular capillaries
2. filtration at the glomerular capillaries |
|
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Term
|
Definition
| Excretion = Filtration - Reabsorption + secretion |
|
|
Term
| What are the two types of nephrons and what percentage of each are in the kidneys |
|
Definition
1. Cortical Nephrons = 75%
2. Juxtamedullary nephrons = 25% |
|
|
Term
| Describe the difference in tightness of the junctions in the nephron |
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Definition
| The nephron starts at the glomerulus capillaries and goes into tubules which are generally loose in their junctions. The junctions grow much tighter as you progress through the nephron to the collecting ducts which have the tightest junctions. |
|
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Term
| What are the three determinants of the glomerular filtration rate? What are their individual pressures in mm Hg? |
|
Definition
1. glomerular hydrostatic pressure (60mmhg)
2. Glomerular colloid osmotic pressure (-32mmHg)
3. Bowman's Capsule Pressure (-18 mmHg) |
|
|
Term
| What is the bowmnan's capsule colloid osmotic pressure? |
|
Definition
| ZERO! There should never be filtration of proteins into the bowman's capsule in a healthy human. |
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|
Term
| If the symbol πB was present on net filtration equation it represents what determining factor of pressure? |
|
Definition
| Bowman's capsule osmotic pressure. (pathological and normally it is zero) |
|
|
Term
| How much reabsorption is possible at the glomerula capillary in the bowman's capsule |
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Definition
| ZERO. The body has the pressures so high going out purposely to prevent any reabsorption. Also there is no venuole end like we see in capillaries in the periphery which would allow for lower pressure to reabsorb fluid. This is done purposely to make sure there is always filtration! |
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Term
| How would constricting the afferent and efferent arterioles at the glomerular effect the GFR? |
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Definition
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|
Term
The filtration factor is derived from?
Goes down if? |
|
Definition
FF = GFR / Renal plasma flow (RPF)
Goes down if decrease GFR and increase RPF. |
|
|
Term
| What influences the net filtration pressures the most? |
|
Definition
| The glomerular colloid osmotic pressure. See power point. Due to water leaving at the beginning portion of the glomerular capillary on the afferent side then there is less fluid on the efferent side so now that protein still present in the blood has even a stronger pressure because there is less fluid for the same amount of protein. As a result less water will want to leave the capillaries on the efferent side because proteins there have a much strong pulling effect to keep them in the capillaries as a result of so much water lost at the beginning afferent side. |
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Term
| What factors will decrease filtration and decrease GFR |
|
Definition
1. decrease hydrostatic pressure of glomerulus
2. Increase osmotic pressure in glomerulus will keep fluid in the capillary and not let it filter out
3. increase Pb which means increase hydrostatic pressure in bowman's capsule which will counter the capillaries attempt to filter out. This caused by blockages in the kidney distal to the tubule. |
|
|
Term
| decrease Filtration and GFR results in more urine or less? |
|
Definition
|
|
Term
| Name three factors that will increase filtration and increase GFR |
|
Definition
1. Increase πB osomotic pressure in bowman's capsule from more proteins leaving the capillaries
2. decrease πG osomotic pressure in glomerula means not enough protein to hold onto water
3. Increase Pg hydrostatic pressure in the glomerular capillaries will cause a large pressure forcing out the capillaries in bowman's capsule |
|
|
Term
| Why is filtration effected more by osmotic pressures than hydrostatic pressures in the kidneys |
|
Definition
| The kidneys nephrons and filtration rates are effected less by hydrostatic pressures because of the ability to increase or decrease the diameter of the afferent and efferent arterioles supplying blood to the glomerular capillaries. The body therefore can adjust the pressures from the heart to best meet the needs of filtration. Osmotic pressure is more labile and has more of an effect on filtration. If protein escapes into bowman's capsule you have a large effect. If protein is low in the capillaries that too will significantly increase your filtration. ect.. |
|
|
Term
| net filtration pressures average around? |
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Definition
|
|
Term
|
Definition
|
|
Term
| The filtration coefficent is expressed as Kf. It is derived from? |
|
Definition
GFR / Net filtration pressure (NFP)
125 / 10 = 12.5 ml/min per mm Hg |
|
|
Term
| Why do the nephrons have a significantly higher filtration coefficent than the capillaries in the peripheral tissues? |
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Definition
| Kidnes have higher filtration coefficent because of its greater permeability of the capillaries (AKA due to its increase conductivity) |
|
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Term
| What happens to nephrons with chronic diabetes the leads to adecrease in filtration coefficent |
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Definition
| Diabetes causes glomerular injury resulting in decrease permeability. The glomerulus is thickened at the basement membrane |
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Term
| Describe the glomerular capillary filtration barrier functioning parts |
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Definition
| basement membrane has negatively charged glycoproteins that prevent proteins (which are negative too) from passing through. Podocytes also have a negative charge that prevents proteins from leaving. H20 and small ions can pass through the podocytes via filtration through the fenestrations of the endothelium then through the basement membrane and then through the slit pores that empty into the bowman's capsule. |
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Term
| What do filtration slits do during filtration in glomerular capillaries? what controls them? |
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Definition
| Filtration slits also known as slit pores are on the outer layer of the glomerular capillaries. They are the final holes that H20 and small ions can leave through. This opening can be squeezed closed by cells (NOT SMOOTH MUSCLE) those cells are called mesangial cells |
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Term
| what are the three hormones produced in the kidneys |
|
Definition
1. renin
2. erythropoietic factor
3. 1, 25 dihydroxycholecalciferol |
|
|
Term
| Renin angitensin aldosterone system responds to what changes in what ions |
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Definition
| Decrease in over all sodium or change in the ratio of Na and Cl |
|
|
Term
| What is renin and what does it do? |
|
Definition
| Renin is an enzyme that converts angiotensin to Angiotensin I |
|
|
Term
| Where does angiotensin I get converted to II and by what? |
|
Definition
| Angiotensin I converted by angiotensin converting enzyme in the lungs to angiotensin II |
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|
Term
| Angiotensin II can stimulate increase secretion of aldosterone from the glomerulosa of the adrenal cortex which will result in |
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Definition
| increase Na reabsorption and K secretion in late Distal tubule and collecting duct. |
|
|
Term
| What four areas does angiotensin II effect? |
|
Definition
1. Increase Aldosterone release
2. tubuloglomerula feedback
3. vasoconstriction of peripheral vessels
4. ? |
|
|
Term
| Can cortisol bind to the mineralcorticoid receptors in the kidneys? |
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Definition
| Normally no. The original shape of cortisol can bind to the aldosterone receptors known as mineralcorticoid receptors. However there are enzymes that change the shape of the cortisol hormone so that it cannot fit into the receptor anymore. A deficiency in this would present as if you had too much aldosterone. |
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Term
| ANP acts on what cells of the kidney. Where does ANP come from? |
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Definition
| principal cells. ANP comes from the stretch of the atrium when there is large volumes in circulation . The ANP hormone binds to a enzymatic protein receptor on the membrane of principle cells in the kidney which activates guaynine cyclase and activates kinase that phosphorylates proteins which block reabsorption of Na from the lumen. And thereby decreases BP |
|
|
Term
| Name three ways ANP works to decrease BP? What exactly do all these ways have in common |
|
Definition
1. Increase Renin release
2. Decrease Aldosterone
3. Increase GFR
All three result in increase Na and H20 excretion. |
|
|
Term
| Name two ways calcium can be reabsorbed |
|
Definition
| 1. Cross the cell via active and passive transport 2. in between cells H20 and Ca can squeeze through (paracellular) |
|
|
Term
| Name 7 functions of the kidney |
|
Definition
1. Regulation of extracellular fluid volume and BP
2. Regulation of osmolarity
3. maintenance of ion balance
4. homeostatic regulation of pH
5. excretion of waste
6. production of hormones
7. gluconeogenesis |
|
|
Term
| What % of the plasma entering the bowman's capsule in the afferent artery enters the capsule? |
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Definition
| 20%. But 19% of this is reabsorbed before it is reaches the bladder. |
|
|
Term
| As the hydrostatic pressure from the afferent end of the glomerulus decreases towards the efferent end; what is happening to the osmotic pressure and why? Is it going up or down? |
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Definition
| The osmotic pressure increases towards the efferent end of the glomerulus because there is a higher ratio of proteins to water. (B/c a lot of water is lost in filtration prior) The lower the ratio of protein to the surrounding plasma fluid means those proteins have a higher pressure. |
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Term
| The end of the collecting ducts at the largest section is known as? |
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Definition
|
|
Term
| What percentage of the cardiac output goes to the kidneys? |
|
Definition
|
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Term
| Filtration can only occur if the pressure inside the capillaries is less or higher than the pressure out? |
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Definition
| Pressure inside the capillaries must always be higher than the pressure outside in order for filtration to occur. |
|
|
Term
|
Definition
| the ultrafiltration coefficent |
|
|
Term
|
Definition
| surface area and contraction of mesangial cells. So Kf describes how permeable a membrane is. The more surface area than the more places for substances to move across and therefore the more permeable that membrane can be. If the surface of the glomerulus is damaged then there are less areas for filtration and the Kf is lowered. If mesangial cells are contracting then that will decrease the surface area as well and lower the Kf. |
|
|
Term
| What two diseases cause an increase in the thickness of the basement membrane? |
|
Definition
|
|
Term
| what are three characteristics that decide whether or not a molecule can be filtered at the glomerulus? |
|
Definition
-molecular weight and radius
-charge on molecule
-shape of molecule (globular and rigid, less clearance) |
|
|
Term
| what is the difference between transcellular and paracellular transport? What are the types of transport that follow these paths? |
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Definition
| Transcellular tx occurs through the cell while paracellular occurs between two cells. This describes re-absorption the movement of water and solutes from the lumen through the endothelium to the capillaries. Movement between cells or through cells is done by active transport, passive transport and osmosis. |
|
|
Term
| what does obligatory reabsorption refer to? |
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Definition
| Water must follow solutes in higher concentration so its obligated! So since 65% of ions are reabsorbed in the proximal tubule then an equal ratio of water is also reabsorbed. |
|
|
Term
| what does the transport maximum (Tm) for glucose refer to? What is the Tm for glucose? |
|
Definition
| Refers to the maximal amount of glucose that the kidneys are able to reabsorb from filtration and not waste. The Tm for a health person is approximately 375 mg/ min. DKA patients will have such high sugars that these active transport systems cannot keep up and therefore we have glucose in the urine. |
|
|
Term
| Name 7 functions of the kidney |
|
Definition
1. Regulation of extracellular fluid volume and BP
2. Regulation of osmolarity
3. maintenance of ion balance
4. homeostatic regulation of pH
5. excretion of waste
6. production of hormones
7. gluconeogenesis |
|
|
Term
| What % of the plasma entering the bowman's capsule in the afferent artery enters the capsule? |
|
Definition
| 20%. But 19% of this is reabsorbed before it is reaches the bladder. |
|
|
Term
| Normal osmolarity reflects? Whats the range |
|
Definition
| Reflects the osmotically active particles not the weight. Normal range is |
|
|
Term
| When you drink a liter of water does the osmolarity of the plasma change? What happens to the urine osmolarity? |
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Definition
| The plasma molarity has a very minimal change but the urine osmolarity has a very large change as the kideny excretes the large amount of water that you don't need. |
|
|
Term
| Why does the osmolarity of the urine double at the descending loop of henle as it was from the glomerulus? |
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Definition
| The descending loop of henle is very permeable to water and the body absorbs a large amount 65% here. So there is a large amount of solutes remaining in the tubule which causes the osmolarity to go up. |
|
|
Term
| At what point in the nephron system does the body begin removing solutes and bringing down the osmolarity of the urine? |
|
Definition
| On the ascending loop of henle and distal tubule a large amount of solutes (mostly Na and Cl) are reabsorbed to the body and this dilutes the urine and therefore dilutes the urine. |
|
|
Term
| Normally with the help of ADH where will more H20 be reabsorbed by aqua porins? |
|
Definition
| In the late distal tubule and collecting ducts. |
|
|
Term
| where is NaCl reabsorbed...late or early distal tubule? |
|
Definition
|
|
Term
| Is more water reabsorbed in the cortex region or medulla region of the nephron? |
|
Definition
|
|
Term
| Whats the main difference between peritubular capillaries and vasa recta capillaries? |
|
Definition
| Peritubular capillaries are mainly found in the cortical nephrons and primarly serve the functions of secretions and reabsoption due to their rich capillariy beds against the nephron tubules. The vasa recta capillaries are mostly in the juxtaglomerular nephrons and heavily focused in the loop of henle where they serve more of an osmosis purpose. Vasa recta also known as osmotic exchangers. |
|
|
Term
| What/and where is the most contributing factor for the countercurrent multiplier? |
|
Definition
| Active transport mechanisms in thick ascending loop of Henle which transport Na, Cl and K out of the nephron and back into the plasma. |
|
|
Term
| What is countercurrent multiplier in the kidneys |
|
Definition
| This is mechanism used in the kidenys that uses energy to maintain a concentration gradient so that the kidney's don't excrete the full 20% that is filtered out of the blood at the glomerularis. IF that was so then there would be an imbalance to the concentration gradients that are vital to life for action potentials. The kidney does this via the anatomy of the kidney's nephrons. So the descending loop of henle has lots of aqua porins but no active transport. So lots of H20 leaves the nephron during its descent through the loop of henle. Now there are higher concentrations of solute as the urine begins to travel up the ascending loop. The ascending loop of henle has no aqua porins so no H20 is reabsorbed. But it does have active transport pumps which use energy to remove Na, Cl, and K to the interstitial space. Now remember the loop of henle is in the same general space. So the more those active pumps pump solutes into the interstitial space in the ascending limb that will create a multiplying effect to draw more H20 (increase osmosis) out of the proximal limb of henle because the solutes effect all the interstitial space. H20 follows Na. Since there are on aqua porins in the ascending loop to allow H20 to flow into the interstitium then the water will flow from the descending loop at a higher rate. Multiplying effect!! |
|
|
Term
| What does the obligatory urine volume refer to? |
|
Definition
| amount of urine volume necessary to remove the waste present |
|
|
Term
| In renal disease what happens with the obligatory urine volume? |
|
Definition
| The damaged kidneys are not able to concentrate urine with solutes as effectively and the obligatory urine volume is therefore increased. So it takes more overall volume of urine excretion to get all the waste disolved and out of the body versus a healthy kidney which can remove the same amount of waste in only half of the volume of excretion. |
|
|
Term
| whats the main difference between central and nephrogenic diabetes in relation to ADH |
|
Definition
| central DI there is not enough ADH production. While nephrogenic DI there is enough ADH but the kidneys are not responsive. |
|
|
Term
| Osmotic diuretics works on what part of the kidney nephron? What is its mechanism of action? |
|
Definition
| Works mostly on the proximal tubules by inhibiting water and solute reabsorption by increasing the osmolarity of tubular fluid. |
|
|
Term
| Loop diuretics work on what part of the kidney? what is its mechanism of action? |
|
Definition
| Works on thick ascending loop of henle and inhibits Na, K , Cl co-transport. |
|
|
Term
| Why are diuretic effects limited? |
|
Definition
| The renin angio aldosterone system begins to kick in and take control of solute excretion and overall reabsorption |
|
|
Term
| Name two types of osmotic diuretics. How doe they work? |
|
Definition
1. mannitor
2. sucrose
They are osmotically active and when they enter the tubules they cannot be reabsorbed by anything so they hold alot more H20 in the tubules with them. |
|
|
Term
| Whats the main transport protein that is inhibited by the loop diuretics and where in the nephron is this occuring? |
|
Definition
| Effects the Na/Cl/K (all in one) co-transporter in the thick ascending limb of henle. |
|
|
Term
| Downside of loop diuretics as a result of shutting down the _____ pump what does that do to other Ion balances in the body? |
|
Definition
| They eventually decrease the osmolarity of the intersitial space. This then can effect aldosterone resulting in hypokalemia since aldosterone now will release more K. Also there is more of a loss of H ions (alkalosis develops) because more H ions are excreted since there is higher Na in the lumen than more coutnertransport of h out into the lumen and Na into the interstial space. |
|
|
Term
| How do carbonic anhydrase diuretics work? |
|
Definition
| Carbonic Anhydrase inhibitors work by inhibiting H secretion and HCO3 reabsorption which results in reduction of Na reabsorption. |
|
|
Term
| Where is erythropoietin released and what stimulates its release? Acts on where to increase RBC production? |
|
Definition
| Released in AFFERENT Arterioles by juxtaglomerular cells. Stimulus for secretion are hypoxia and decreased RBF. Acts on the bone marrow to increase RBC production. |
|
|
Term
| What disease would decrease aldosterone? And result in the decrease sodium resorption and how would that effect their serum K levels? |
|
Definition
| Addison's disease is where the adrenal gland destroys the parts of the cortex and results in decrease aldosterone. Less aldosterone means lower reabsorption of Na which means lower serum Na levels and as a result higher K serum levels. |
|
|
Term
|
Definition
| transitional epithelial cells with layers of smooth muscle. Smooth muscles help with peristaltic contractions to makes sure the urine gets to the bladder |
|
|
Term
| What is the function of the rugae in the bladder? |
|
Definition
| The function of the rugae is to allow the bladder, or other tissue, to expand when needed. When the bladder is not full, the rugae are folds in the tissue. However, as the stomach fills it expands by unfolding the rugae. Upon emptying, the reformation of the rugae causes the bladder to recede to its former size. |
|
|
Term
| Whats unique about the center of trigone? |
|
Definition
| Part of the bladder in the lowest part where urine drains into the urethra. This is area does not have rugae and instead is smooth to allow for easy flow of urine out of the bladder. |
|
|
Term
| How many urethral sphincters are there? What are the differences between the two? |
|
Definition
| Internal urethra is subconscious control and made up of smooth muscle. The external urethra is made up of skeletal muscle. Conscious control will releax it and allow urine to pass. |
|
|
Term
| What nerve innervates the external sphincter? |
|
Definition
|
|
Term
| What is the name for the smooth muscle that surrounds the bladder and helps contract it when stimulated by what nerve after stretch fibers activated. |
|
Definition
| Detrusor smooth muscle surrounds the bladder and is stimulated by stretch receptors. The efferent nerve to the detrusor is a parasympathetic nerve called the pelvic nerve. |
|
|
Term
| Whats the difference in mechanism of action between innervation of the smooth muscle by sympathetic and parasympathetic nerve in the bladder. |
|
Definition
| Sympathetic stimulation via the hypogastric suppresses contraction of the detrusor smooth muscles of the bladder while parasympathetic stimulation via the stretch reflex and pelvic nerve will contract the detrusor muscles. |
|
|
Term
| Why are babies incontinent? |
|
Definition
| Its reflexive and infants lack the comprehension for voluntary release of the external sphincter. Also they lack alot of skeletal muscle to control the external sphincter. |
|
|
Term
| At what pressure in the bladder would the external sphincter likely open up against voluntary control? |
|
Definition
| 500 mL. Not only the pressure from this large volume will do this but also the involuntary contractions of smooth muscle from the micturition reflexes will too. |
|
|
Term
| What are some common age related changes in kidney / urinary system? |
|
Definition
Decline in the number of functional nephrons
Reduction of GFR
Reduced sensitivity to ADH
Problems with the micturition reflex |
|
|
Term
| Faconi syndrome results in? what part of the nephron most commonly effected? |
|
Definition
| Causes an overall decrease in reabsorption bicarb, phosphate, glucose and/or amino acids at the proximal tubules |
|
|
Term
| Renal failure or insufficiency refers to a reduction in what? |
|
Definition
| GFR. The degree of remaining normal GFR decides where it is failure or insufficiency |
|
|
Term
| Renal Insufficiency the remaining normal GFR capacity is only? |
|
Definition
|
|
Term
| In renal failure the remaining functional GFR capacity is only? While in end stage renal failure that number drops to? |
|
Definition
Renal failure: 10-25%
End stage renal disease: <10-15% |
|
|
Term
| vasculitis and acute glomerulonephritis cause what kind of renal failure |
|
Definition
|
|
Term
| tubular necrosis – ischemia,toxins, heavy metals, CCl4 cause what type of renal failure |
|
Definition
|
|
Term
| heart failure causes what type of renal failure |
|
Definition
|
|
Term
| renal artery stenosis causes what kind of renal failure |
|
Definition
|
|
Term
| kidney stones cause what kind of renal failure |
|
Definition
|
|
Term
| Prostate disease causes what kind of renal failure |
|
Definition
|
|
Term
| chronic renal disease is slow and changes the physiology / structure of the kidney by causing ____ and ____ of surviving nephrons |
|
Definition
| hypertrophy and vasodilation |
|
|
Term
| hypertrophy, vasodilation and increase arterial pressure on the nephrons will result in? |
|
Definition
| increase glomerular pressure and increase filtration. |
|
|
Term
| pH changes effects what functions of the body the most? |
|
Definition
| enzymatic functions and proteins. |
|
|
Term
| most important buffer in the intracellular are? |
|
Definition
| protein buffers. Hemoglobulin can act like a buffer in the blood. |
|
|
Term
| What are the three types of buffers. Why does the body need more than one buffer? |
|
Definition
1. bicarb
2. proteins
3. phosphate
Need verious types of buffers to serve different areas of the body such as extracellular or intracellular. Also each of these buffers have different pKAs which will change the pH in different proportions depending on what the body needs and how fast. |
|
|
Term
| Where does bicarb have a bigger role..extraceullular or intracellular? Why? |
|
Definition
| Extracellular. Why? B/c it is more easily regulated in the blood between the lungs and kidneys. |
|
|
Term
| what is the process that occurs with carbonic anhydrase and bicarb ect.. |
|
Definition
|
|
Term
| The majority of CO2 is transported in the blood as? Minority of CO2 is transported? |
|
Definition
| Majority of Co2 is converted to HCO3 while a very small amount is free floating as CO2. (that free form is your partial pressure) |
|
|
Term
| What happens to pH with alveolar ventilation changes? What is the normal alveolar ventilation |
|
Definition
| Normal alveolar ventilation is 1. The more alveolar ventilation then the pH will rise and person becomes more alkalotic. |
|
|
Term
| What happens to alveolar ventilation when the pH becomes more acidoitc |
|
Definition
| Increase alveolar ventilation |
|
|
Term
| Where are the chemorecpeptors located in brain. (3x) |
|
Definition
1. medulla obligota
2. carotid sinuses
3. Aortic notch |
|
|
Term
| pH of urine can be influenced by proteins. Proteins will cause it to be more acidic or basic |
|
Definition
|
|
Term
| The majority 85% of bicarb reabsorption is done in the ___ of the nephron |
|
Definition
| proximal convoluted tubule |
|
|
Term
| pH of urine can be influenced by proteins. Proteins will cause it to be more acidic or basic |
|
Definition
|
|
Term
| Phosphate is mostly reabsorbed in the? |
|
Definition
| 80% reabsorbed in the proximal tubule. |
|
|
Term
| What are two ways for the two ammonium ions to leave the cell after they are made from glutamine metabolism. |
|
Definition
1. Ammoninium ions can leave via counter active transport with Na.
2. Ammonium ions can loose a H ion and become ammonia. Ammonia unlike its ion version can passively leave the cell into the tubule lumen. The remaining H ion can also leave via active transport and the other buffer systems. |
|
|
Term
| The most powerful buffer system in the kidney is which system? Why? |
|
Definition
| Ammonium/ammonia system because the active transport of an ammonium ion will result in the removal of 4x H ions. While the phosphate system only allows for binding of one h ion to each phosphate. THe bicarb system only results in removal of one H ion too at a time. |
|
|
Term
| Na and H pumps are cotransport or counter transporters? |
|
Definition
|
|
Term
| Are K and Na pumps counter or co-transport |
|
Definition
|
|
Term
| glucose and Na pumps are co or counter-transport |
|
Definition
|
|
Term
| What cells secrete potassium? |
|
Definition
|
|
Term
| What cells reabsorb potassium |
|
Definition
|
|
Term
| Explain autoregulation and how it is important for glomerular pressure |
|
Definition
| Autoregulation by the arterioles of the afferent and efferent arterioles ensures that even with wide pressure changes between 60-160 at the afferent artery will not greatly effect the glomerular filtration hydrostatic pressure, thus ensuring the homeostatic filtration amount is consistent. |
|
|
Term
| explain what happens when there is increase arterial pressure and how myogenic mechanism of the smooth muscle autoregulates |
|
Definition
| An increase in pressure to the gomerular capillaries will result in greater filtration beyond what is the normal amount. The arterioles have built in mechanisms to quickly adjust to higher pressures. Higher pressures means more stretch on the endothelium of the arterioles. That results in an influx of calcium which excites the smooth muscle and causes it to contract more. (constrict) More constriction means less blood flow to glomerular capillaries and brings it back to homeostasis. |
|
|
Term
| explain macula densa feedback |
|
Definition
The macula densa is an area with macula densa cells that are on the distal convoluted tubule. These cells are chemoreceptors that pick up the osmolarity of sodium chloride in the late thick ascending limb. These cells are positioned close to the afferent arteriole and the juxtaglomerular cells on the afferent and efferent arterioles. The whole function of the macula densa is to make sure there is enough blood pressure to the glomerular capillaries to make sure our kidneys are able to function properly and excrete waste / maintain homeostasis. The only way it knows if BP is adequate is by indirectly measuring the NaCl levels in the late thick ascending loop of henle. If there is a low BP then there is low Filtration volume. Low filtration volume means less NaCl. So most of that NaCl will have be reabsorbed by the time it got to these receptors. So they realize something's wrong and they need to increase the filtration rate by increasing the hydrostatic pressure in the glomerulus by:
1. vasodilate the afferent arteriole to increase blood flow the glomerular capillary to increase filtration rate and hopefully get more NaCL to the macula densa to shut them up.
2. It also signals juxtaglomerular cells via prostaglandin release to release renin. Renin acts on the efferent arterioles to constrict them. That causes backup of blood into the glomerulus which means more hydrostatic pressure and more filtration and hopefully more NaCl to float by the macula densa to shut them up.
Goal? Feedback! It adjusts noticing there is less NaCl so it increases NaCl by increasing hydrostatic pressure in the glomerulus. |
|
|
Term
| What stimulates ADH to be released from posterior hypothalamus to stimulate increase water reabsorption in the collecting ducts? |
|
Definition
| ADH is stimulated by baroreceptors and osmoreceptors in the brain to low osmolarity and low BP. ADH also stimulates renin to be released which will vasocontrict after it changes angiotensin 1 to 2. |
|
|
Term
| When would you have a thirst mechanism activated? When ADH is increased or lowered? |
|
Definition
| Increased! Because ADH increase means you want more water in the body so at the same time your body will want to drink more water to help the kidney's conserve water and dilute the higher osmolarity that was present to stimulate ADH release in the first place. |
|
|
Term
| What type of aquaporins are made in response to ADH and where are they located? |
|
Definition
| Aquaporin 2s respond to ADH. They are located in the late distal tubule and collecting ducts. |
|
|
Term
| explain the mechanism of action of ADH on the cells in the nephron |
|
Definition
|
|
Term
| How do renin inhibitors work? 3x |
|
Definition
decrease aldosterone
directly inhibit Na+ reabsorption
decrease efferent arteriolar resistance |
|
|
Term
| Increase in blood volume stretches the right atria which will release ANP. ANP will decrease blood volume via three ways... |
|
Definition
1. Decrease renin release
2. decrease aldosterone release
3. increase GFR |
|
|
Term
| Will ANP release increase or decrease GFR? |
|
Definition
| Increase! The atrial stretch receptors sense too much volume in the right atrium and want to decrease the volume. So it does this by making the kidney's pee out the extra volume. |
|
|
Term
| ANP does the exact opposite of what hormone? |
|
Definition
|
|
Term
| whats the ratio between bicarb and co2 in order to have a 7.4 pH |
|
Definition
|
|
Term
| The anion gap refers to a measurement of what? |
|
Definition
| The anion gap represents the missing unmeasured amount of anions not measured with serum lab tests. The unmeasured anions always in the body can change. Normal it reflects proteins, phosphates, lactate, |
|
|
Term
| Anion gap can occur as a result of an increase in acids or a loss of? |
|
Definition
| increase in acids organic and inorganic |
|
|
Term
| Increase anion gap can be caused by? |
|
Definition
1. lactic acidosis
2. DKA
3. ASA overdose
4. methanol overdose |
|
|
Term
| normal intracellular fluid is around ___ L |
|
Definition
|
|
Term
| Normal interstitial fluid is approximately _____ L |
|
Definition
|
|
Term
| Normal plasma fluid level is approximately ____ L |
|
Definition
|
|
Term
| Extracellular fluid includes interstitial and plasma volume and that total is around _____L |
|
Definition
|
|
Term
| The biggest factor in why different people have different total body water is effected from the amount of ___ they have |
|
Definition
|
|
Term
| Will the leaner or more fat person have the larger percentage of total body weight |
|
Definition
| Leaner people will have more total body water % |
|
|
Term
| Where is our thirst mechanism located? |
|
Definition
| In the perioptic nuclei of the posterior hypothalamus |
|
|
Term
| What stimulates a feeling of "thirst"? |
|
Definition
| The osmolarity of the blood is sensed by osmolality sensors which are preoptic nuclei in the hypothalamus. |
|
|
Term
| name five factors that stimulate thirst |
|
Definition
1. increased osmolarity
2. decreased blood volume
3. decrease blood pressure
4. increase angiotensin II
5. dryness of mouth. |
|
|
Term
| What's one reflex that prevents us from drinking too much water when our body tells us we need volume? |
|
Definition
| The stomach will become distended and that stretch on the stomach tells the brain to stop eating and to stop being thirsty because the stomach is full and everything in it needs to be digested and absorbed first. |
|
|
Term
| when aldosterone is working on salivary glands, sweat, colon its mechanism of action is? |
|
Definition
| increase Na retention/reabsorption |
|
|
Term
| Do not correct Na levels too quickly because it will do what to the brain? |
|
Definition
|
|
Term
| clearance is defined in terms of ___ per min |
|
Definition
|
|
Term
| To get an accurate clearance you have to use a specific substance with what characteristics? Name a common substance used for this. |
|
Definition
| The substance first must be able to be filtered into the nephron. Then it cannot be reabsorbed or secreted along the nephron. The filtered amount must = the amount excreted. That will tell you the clearance rate of whats filtered compared to volume in systemic circulation. A substance often used is Inulin or creatinine. |
|
|
Term
| creatinine hows downsides to estimating GFR. What are they? |
|
Definition
| Some Creatinine may be secreted into the nephron however its less than 10% |
|
|
Term
| what are the characteristics of a substance you would use to determine renal plasma flow? Whats an example of a good substance for this |
|
Definition
| the substance would have to be both filtered and secreted. Example is para-aminohippuric acid PAH |
|
|
Term
| Why is para-aminohippuric acid PAH not perfect for determining Renal plasma flow? |
|
Definition
| 10% doesn't enter the nephron and instead goes to the veins and tissue of the kidneys. So we have to correct the answer we get and add 10% to it. |
|
|
Term
| what kind of pump do thiazide diuretics work on and where in the nephron does this take place |
|
Definition
| thiazide diuretics work on Na / Cl cotransport pumps in the early distal tubule by blocking them from reabsorbing Na/Cl from the urine to the interstitial fluid. By doing so more H20 will remain in the lumen of the nephron along with the NA and hence why people will pee more. |
|
|
Term
| whats the difference between intercalated discs and principal cells in relation to K. |
|
Definition
| Principal cells secrete potassium into the lumen of the nephron by a one way pump while intercalated cells absorb back potassium through countertransport with H ions. The acid H ions are secreted into the urine by this. |
|
|
Term
| does autoregulation effect urine flow? |
|
Definition
| NO! Autoregulation only controls renal blood flow to ensure the GFR is maintained at the body's homeostatic level. |
|
|
Term
| angiotensin works by increasing? |
|
Definition
| renal tubular sodium reabsorption |
|
|
Term
| Does ANP increase or decrease GFR..Why |
|
Definition
| ANP increases GFR because ANP is only released when there is excess volume of blood returning to the right atrium. The excess blood volume stretches receptors that release ANP that then dilate the afferent arteriole of the glomerulus to increase hydrostatic pressure and filter more volume out of the body via urination and thereby decreasing systemic volume. |
|
|
Term
| If the urine is very concentrated then you would presume ADH levels would be high or low? |
|
Definition
| Higher. Which means lots of water reabsorbed via aquaporins leaving very hyperosmolar urine to be excreted. |
|
|
Term
| most of the water reabsorption occurs in the medulla or cortex? And where exactly at that area? |
|
Definition
| Most water reabsorption occurs in the cortex at the distal convoluted tubule |
|
|
Term
| does the vasa recta or peritubular serve as the countercurrent exchanger? |
|
Definition
| vasa recta of the juxtaglomerular nephrons. The vasa recta has very low blood flow and accounts for only 1-2% of blood supply. |
|
|
Term
| at what point in the nephron is the nephron lumen isoosmolar to the interstitial fluid and why? |
|
Definition
| At the proximal tubule there is approximately 65% of water reabsorption that leaves the tubule to the interstial space that has more solutes than does the lumen of the nephron. This results in a equal osmolarity (= # of solutes) between the nephron lumen and interstitial fluid. To change this balance the nephron later down the tubule will actively pump ions against their gradient which will then cause a "multiplier" effect to force water to follow the Na. |
|
|
Term
| what is obligatory urine volume? |
|
Definition
| In order for the body to remove waste it needs fluid for it to dissolve in so that it can flow out of the body via excretion. Otherwise the waste would accumulate as trash and clog everything up. So the obligatory urine volume is the amount of fluid needed to dissolve all the waste from the body in order to get it out via excretion. |
|
|
Term
| nephrogenic diabetes is failure to produce or respond to ADH? |
|
Definition
|
|
Term
| central diabetes insipidous is failure to produce or respond to ADH? |
|
Definition
|
|
Term
| Causes of nephrogenic diabetes insipidus |
|
Definition
| drug induced renal damage: lithium, analgesicspyelonephritis, hydronephrosis, chronic renal failure loop diuretics |
|
|
Term
| 5 things that cause hypokalemia |
|
Definition
1. excess insulin
2. loop and osmotic diuretics
3. aldosterone
4. diarrhea
5. metabolic alkalosis |
|
|
Term
| Will alkalosis cause hypo or hyper kalemia |
|
Definition
|
|
Term
| spirlactone will increase or decrease K? |
|
Definition
| Increases K levels because it blocks the mineralcorticoid receptors in principal cells that normal increase Na/K exchangers and results in less exchange from the inerstitium so more k left in blood while more Na left in pee so water will follow and body will be diuresed. |
|
|
Term
| Where are the ureteral openings in the bladder located? What surrounds them? |
|
Definition
| The ureteral openings in the bladder are posterior and at the bottom of the bladder. Above them are multiple folds known as rugae that expand when there is volume and fold up when there is no pee collection. Below the ureters is the center of trigone which has a very different shape than rugae. It is smooth and lined to allow urine to freely pass down into the urethra. |
|
|
Term
| describe the micturition reflex |
|
Definition
| The as the bladder fills with urine it stimulates stretch receptors that relay information to the brain. Along the way at the spinal cord there is a relay (reverberant pathway) that also sends an EFFERENT signal via parasympathetic to the bladder to contract. The more the stretch the more the efferent signals to tell the bladder to contract more. The strengths of the contractions intensify in proportion to the increasing volume in the bladder. |
|
|
Term
| name two types of abnormal tubular function |
|
Definition
1. franconi syndrome
2. Renal tubular acidosis |
|
|
Term
| franconi syndrome is a disease to what part of the nephron |
|
Definition
|
|
Term
| two common causes of franconi sydnrome are? |
|
Definition
1. heavy metal ingestion
2. genetics |
|
|
Term
| what disease will cause decrease K excretion and Na absorption. |
|
Definition
|
|
Term
| what disease will cause decreased Na+, Ca++, HCO3- reabsorption, hypotension |
|
Definition
|
|
Term
| what disease results in decrease H20 reabsorption and hypernatremia |
|
Definition
|
|
Term
| whats the role of carbonic anhydrase in the buffer system of the body? |
|
Definition
| It combines CO2 and H2O together to form H2CO3. |
|
|
Term
| What enzyme catalyzes the formation of bicarb and H2CO3? Where is this enzyme found? |
|
Definition
| carbonic anhydrase found in red blood cells catalyze the hydration of CO2 with H20 to form bicarb HC03 and H2CO3 |
|
|
Term
| what does chloride shift refer to in relation to red blood cells and buffer system |
|
Definition
| Bicarb and Chloride are always moving in opposite directions in order to maintain a consistent negative charge. So if bicarb leaves hemoglobin than Cl enters. |
|
|
Term
| do the kidneys secrete volatile or non-volatile acids? |
|
Definition
|
|
Term
| Explain how the kidney's contribute to acid/base balance of the body |
|
Definition
| Kidney's excrete H, excrete non-volatile acids such as H2SO4, H3PO4, reabsorb bicarb, make new bicarb, and secrete H ions. |
|
|
Term
| what kind of pump is used for bicarb reabsorption? Where is the majority of bicarb reabsorbed? |
|
Definition
| Counter active transport H / Bicarb pumps are used primarily in the proximal tubule to reabsorb approximately 85% of Bicarb. For every bicarb reabsorbed then there is 1x H ion secreted. |
|
|
Term
| How does the intercalated discs in the collecting tubules differ in how they secrete H ions and reabsorb HCO3? |
|
Definition
| hydrogen ion secretion in the collecting tubule is mediated by a H+ ATPase pump in the luminal membrane and a Cl-HCO3- exchanger in the basolateral membrane |
|
|
Term
IF a person is in resp alkalosis how will the body respond in regards to
1. reabsorption of HCO3
2. secretion of H ions
3 HCO3 secretion |
|
Definition
1. Decrease reabsorption of HCO3
2. Decrease Secretion of H ions
3. Increase HCO3 |
|
|
Term
| why is there a rebound alkalosis from diuretics? |
|
Definition
| Loop diuretics block Na/K/Cl pumps at the thick ascending loop of henle. This results in larger amounts of ions in the lumen. Large concentrations of negative Cl ions in tubular lumen will favor H + ions to move from the cells/interstital fluid to the lumen in the distal tubule. Also due to effects of aldosterone; Na can be exchanged for K or for H if low levels of K. So Loop diuretics block K reabsorption at the K/Na/Cl pumps on thick ascending which means further down the nephron at the collecting ducts there are less K ions in the interstitial fluid. For aldosterone to work here it needs K in the interstitial fluid to excrete out in exchange for Na. So Now it makes up for this lack of K because of diuretics and exchanges H ions instead for Na reabsorption. This further causes metabolic alkalosis. |
|
|
Term
| in a normal human the total anions should equal or be more than the total cations |
|
Definition
|
|
Term
| why is unmeasured cations normally omitted from the anion gap? What are the tow omitted cations? |
|
Definition
| Cations have a + charge. Mag and Ca are omitted from the anion gap because their concentrations are so small that they are not needed to evaluate the anion gap. |
|
|
Term
| Normal Anion Gap is? Why isn't zero if we already know anions = cations |
|
Definition
| 8-16. There are more unmeasured anions than there are cations. So when you do the equation out there are more MEASURABLE cations (More unaccounted for anions which would have brought this number down to zero) resulting in a number that is not zero. |
|
|
Term
| acids are anions or cations? |
|
Definition
| Anions and usually are unmeasurable in the blood so we account for them in the anion gap equation. |
|
|
Term
| why is there no change in the anion gap for hypercholoremic acidosis? |
|
Definition
| The anion gap remains unchanged because chloride is measurable first of all so its factored into the equation. Secondly there is more chloride in the blood/interstitium therefore favoring more bicarb secretion and decrease bicarb reabsorption to balance the electronegativity of the plasma from the high Cl. |
|
|
Term
| For pathologies such as DKA or lactic acidosis there is an increase in the anion gap but what happens to the chloride? |
|
Definition
| Cl is normal or doesn't effect the anion gap. That is why conditions such as DKA and lactic acidosis is called normochloremic acidosis. |
|
|
Term
| if Cx < CInulin then there was tubular secretion,reabsorption, or neither? |
|
Definition
|
|
Term
| if Cx > CInulin then there was tubular secretion,reabsorption, or neither? |
|
Definition
|
|
Term
| if Cx = CInulin then there was tubular secretion,reabsorption, or neither? |
|
Definition
| Neither. Just like inulin all of substance x at the bowman's capsule is excreted in the urine without any of it being reabsorbed and without any more of x being added to the urine via secretion. |
|
|
Term
| In descending order list who has more total body water. Infants, Men, Women |
|
Definition
|
|
Term
| normal mL of fluid intake is ? |
|
Definition
|
|
Term
| normal mL of output for the body is? |
|
Definition
|
|
Term
| Normal insensible loss is around ___ mL. Insensible loss is from ____ and ______ |
|
Definition
| 700mL of insensible loss daily from the skin and lungs. |
|
|
Term
| describe the thirst mechanism of the body |
|
Definition
| Osmolarity receptors in the hypothalamus detect high concentrations of solute and recognize the body needs more fluid. So it stimulates ADH release to retain fluid and to stimulate body to want to drink more water. |
|
|
Term
| name five stimuli for thirst |
|
Definition
Increased osmolarity
Decreased blood volume
(cardiopulmonary reflexes)
Decreased blood pressure
(arterial baroreceptors)
Increased angiotensin II
Other stimuli:
- dryness of mouth |
|
|
Term
| tubularglomerular feedback will vasoconstrict which arteriole |
|
Definition
|
|
Term
| the most important determinant of Extracellular fluid volume is? |
|
Definition
|
|
Term
| increase ingestion of Na results in inc or dec of renin? |
|
Definition
| Decrease renin because your BP/ECFV will go up as a result of exogenous salt being added therefore RAAS doesn't need to do the same thing. |
|
|
Term
| Cells shrink due to ___natremia |
|
Definition
|
|
Term
| Hyponatremia will cause cells to shrink or swell |
|
Definition
|
|
Term
| what kind of rapid Na change will potentially cause vessels to tear in the brain? |
|
Definition
| Shrinking from hypernatremia |
|
|
Term
| glutamine is broken down into ___ and ____ |
|
Definition
| 2 bicarbs and 2 NH4 ammonium ions |
|
|
Term
| What is the difference between ammonia/ammonium buffer systems in the collecting ducts compared to tubules? |
|
Definition
| In the tubules there is active transport of NH4 (4x hydrogens) and by passive diffusion of NH3 versus in the collecting ducts there is passive removal of only NH3 (3x hydrogen) which then can bind to H+ ions in the tubular lumen |
|
|
Term
| the unmeasured anions in the body is what contributes to the anion gap. The more unmeasured anions than the larger the gap. Name some of these unmeasured anions |
|
Definition
1. SO4
2. PO4
3. Albumin
4. inorganic acids
5. lactic acid / ketones |
|
|
Term
| Name four conditions that can cause metabolic acidosis with a normal anion gap but large Cl count. |
|
Definition
1. diarrhea
2. renal tubular acidosis
3. addison's disease
4. carbonic anhydrase inhibitors. (some of the transport of HCO3 requires CL for countertransport so if HCO3 is not being made by CA then CL will remain in the peritubular capillaries and interstitial fluid. |
|
|
Term
| normal renal plasma flow is? What substance do we use to test this? What characteristic of this substance is necessary for it to be an effective test of renal plasma flow? |
|
Definition
| Normal renal plasma flow is approximately 625 mL/min. We use PAH para-aminohippuric acid to test the renal plasma flow. Its not reabsorbed and almost all of it is excreted by the body via filtration at the glomerulus and secretion at the peritubulars. |
|
|
Term
| What is the purpose of inulin? What is a substitute for using inulin? What does it reflect? |
|
Definition
| Inulin is not a natural substance found in the body. It is unique in that it can only leave the blood via filtration a the glomerulus. It cannot be secreted or reabsorbed at the peritubular capillaries. Therefore it is a good indicator as to how healthy the glomerulus and the overall filtration abilities of both kidney's. The clearnance of inulin gives us the GFR of a person. A substitute for this substance is creatinine. |
|
|
Term
| What is normal renal blood flow? How is it determined? How much of the entire systemic blood flow goes to the kidneys? |
|
Definition
| Renal blood flow is approximately 1,200 mL/min and the body sends about 20% of its blood to the kidneys. To determine renal blood flow you need to know the hematocrit and renal plasma flow. RBF = RPF / (1-hematocrit). Why do we 1-hematocrit? Hematocrit is a percentage out of 100% or out of "1". IF we minus out the hematocrit we are left with the systemic plasma concentration in the blood. The plasma concentration is what we want to divide by because it will lets us know how much blood we are actually flowing at our kidneys in comparison to whats available in the entire body. So now if we apply this to a sick person then if a person has kidney's that don't do a great job at filtering and secretion of nasty waste that is building up in the body then we got a problem. Renal plasma flow would be lower (lets say 500) because that reflects the kidney's poor job at filtration and secretion. If the body's CBC was normal and say their hematocrit was 42%. Then we would change the percentage lab value of hematocrit back to a decimal of 0.42. Then 1-0.42 = 0.58. The 0.58 is the plasma in the body. 500/0.58 = 862 mL/min. Thats bad! What if someone was also anemic and their RPF was bad too at 500 and hematocrit now is only 28% ? 500/0.28 = 694 mL/min. EVEN WORSE. So for healthy blood flow with all the waste that needs to get removed we need good kidneys and good complete blood values. |
|
|
Term
| What is the filtration fraction? Whats its significance? How is it determined? |
|
Definition
| Filtration fraction is just one look at one specific area of the kidney as a way to see how it is functioning. Filtration fraction only reflects filtraiton. And filtration only occurs at the glomerulus in the bowman's capsule. So filtration fraction is reflective of how healthy a glomerulus is by its ability to filter and also reflects the arterioles systems going to it and from it since they also influence its ability to filter. Normal filtration fraction is GFR/RPF. Why? Well RPF is reflective of the total amount of plasma both kidneys can completely remove from the blood running through the kidneys. GFR is only one part of the RPF. RFP is filtration plus secretion while GFR is reflective of only filtration. So we divide GFR from the RPF to get a fraction of how much the glomeruluar filtration is contributing to the overall excretion and removal of plasma from blood. Normal kidneys will remove 20% of all plasma passing by it in the renal blood flow. |
|
|
Term
| the tightest junctions in the nephron are located where? |
|
Definition
| in the collecting tubules |
|
|
Term
| vasa recta asscoiated with what types of tubules |
|
Definition
|
|
Term
| Are there more juxtaglomerular or cortical nephrons? |
|
Definition
| cortical nephorns make up 75% of all nephrons |
|
|
Term
| What is the SBP in the renal artery? |
|
Definition
|
|
Term
| what is the venous pressure of a peritubular artery |
|
Definition
|
|
Term
| Kf estimated by X / Y. Normal Kf is? |
|
Definition
Kf = GFR / Net filtration pressure
Kf = 125 mL/min / 10 mm Hg.
Kf = 12.5 mL/min/mm Hg |
|
|
Term
| Kf is affected by what two things? |
|
Definition
1. surface area of the glomerulus
2. Contraction of mesangial cells. |
|
|
Term
| Do capillaries have smooth muscle? |
|
Definition
|
|
Term
| WHat increases the thickness of the glomerular capillary membrane? |
|
Definition
|
|
Term
| What characteristics of a molecule will decide whether or not it is filtered? |
|
Definition
1. its size / shape
2. its charge
3. weight |
|
|
Term
| A molecule that is globular or rigid will have more chance or less chance for clearance / filtration? |
|
Definition
| LESS!!! RBCs are globulin and they don't filter. Also rigid means its less likely to squeeze through the endothelial fenestration |
|
|
Term
| what type of movement of ions is done between cells? paracellular or transcellular |
|
Definition
|
|
Term
| what structure in the proximal tubule is unique to it and allows for more reabsorption? |
|
Definition
| Microvilli in the proximal tubule allow for more surface area and therefore more reabsorption. Also the junctions are loose / leaky. |
|
|
Term
| How would filtration fraction at the glomerular capillaries effect peritubular capillaries. |
|
Definition
| Well if a larger percentage of plasma is filtered at the glomerular capillaries then the concentration of blood the leaves the glomerulus to the peritubular capillaries will be much more viscous. Therefore the oncotic pressure of proteins will be higher at the peritubulars if the filtration fraction is higher at the glomerulus. |
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Term
| The only time glucose would not be fully reabsorbed in the proximal tubule would be when? |
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Definition
| If glucose threshold for reabsorption is exceeded. |
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Term
| what are the different ways glucose is reabsorbed into the blood? where does this occur |
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Definition
| All glucose should be reabsorbed from the lumen at the proximal tubule either through passive diffusion via Glut 1 and 2 channels or secondary active co-transport with Na. |
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Term
| transport maximum for glucose is? what is glucoses renal threshold? |
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Definition
| 375 mg/min is the most amount of glucose the kidney's can reabsorb. While renal threshold refers to the amount of glucose in the renal blood that must be present before it is filtered out into the ultrafiltrate. That is around 250 mg/dl. |
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Term
| Na/K pumps on the _____border aid in Na re-absorption |
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Definition
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Term
| When we refer to "leaky" membranes we are typically referring to what route of transport? |
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Definition
| paracellular (in between cells) if cells are tight then things can't slip between them. |
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Term
| 65% of mag re-absorption occurs where? |
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Definition
| thick ascending limb of henle |
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Term
| is the thick loop of henle permeable to H20 |
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Definition
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Term
| The nephron is not permeable to urea at what parts of it? |
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Definition
| late distal and collecting tubules. |
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Term
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Definition
| GFR response to constriction of the efferent arteriole. The GFR will increase to a certain point of applying constriction to the efferent arteriole but after too much constriction then the GFR drops. |
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Term
| what does endothelin hormones do to afferent and efferent arterioles? where does it come from? |
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Definition
| Endothelin comes from local damaged endothelium. It causes vasoconstriction. |
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Term
| angiotensin II works primarily on which arteriole of the kidney? How is GFR and RBF effected? |
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Definition
| works mainly on the efferent arteriole to cause constriction and that results in increase GFR and decrease RBF. |
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Term
| what hormone primarily constricts the afferent arteriole of the kidney? |
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Definition
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Term
| bradykinin will vasodilate or vasoconstrict? |
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Definition
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Term
| What does dopamine do to the kidney? |
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Definition
| Dopamine causes vasodilation of arterioles in kidneys while it causes vasoconstriciton on the peripheral arteroles. which means more GFR and more RBF |
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Term
| Is the built in autoregulation of the renal blood flow influenced by hormones or nervous system? |
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Definition
| NO. ITs independant and will do what ever necessary to filter wastes even if it means sacraficing some of the renal blood flow for GFR |
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Term
| Name two mechanisms that contribute to autoregulation in the kidneys |
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Definition
1. Myogenic mechanism. Increase BP means increase stretch which elicits smooth muscle contraction to turn down BP
2. Tubuloglomerular feedback: the arterioles in the glomerular will feedback to make sure always enough GFR. So efferent will constrict and afferent will dilate. |
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Term
| the macula densa cells of the distal tubula of the juxtaglomerular apparatus also signal the ______ to ______ to increase GFR if they sense a decrease in Na or NA/Cl concentrations |
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Definition
| Macula densa cells via prostaglandin chemical messengers stimulate AFFERENT arterioles to vasodilate to increase GFR and increase Na/Cl concentrations. |
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Term
| Most of renin is secreted from the afferent or efferent arterioles. Angiotensin mostly stimulates efferent or afferent? |
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Definition
| Most renin is from the afferent arterioles while angiotensin causes constriction to the efferent arterioles. |
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Term
| Name two mechanisms that contribute to autoregulation in the kidneys |
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Definition
1. Myogenic mechanism. Increase BP means increase stretch which elicits smooth muscle contraction to turn down BP
2. Tubuloglomerular feedback: the arterioles in the glomerular will feedback to make sure always enough GFR. So efferent will constrict and afferent will dilate. |
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Term
| high protein diet does what to GFR And RBF? |
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Definition
| increases GFR and RBF because of high glromerular pressures and hyperfiltration. Why? Because more protein means more amino acids and amino acids do get filtered. But they get reabsorbed 100% in the proximal tubule by Na co-transport. As a result more Na get reabsorbed with more amino acids. Cl follows Na usually and so does H20. So blood volume goes up. As volume goes up so does hydrostatic pressure in the glomerulus. Also macula densa senses less Na and less Cl. So it also tells afferent to release renin to cause angiotensin to constrict efferent to cause increase GFR. |
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Term
| nicotine, nausea and morphine cause ADH release or inhibition? |
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Definition
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Term
| cardiovascular reflex stimulation occurs when blood loss is > ________. that stimulates ADH release |
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Definition
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Term
| Whats the difference in the location of aquaporins 2, 3, 4 in the late distal tubule and collecting ducts? |
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Definition
| aquaporins 2 area made and placed on the luminal side in response to ADH. While Aquaporins 3 and 4 are on the basolateral side. |
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Term
| ADH can influence an increase in urea reabsorption where? |
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Definition
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Term
| PTH causes increase in Ca reabsorption and decrease re-absorption of ? |
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Definition
| PO4 at the proximal tubule. |
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Term
| normal range of specific gravity for urine |
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Definition
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Term
| concentration of urine depends on 2x things |
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Definition
1. amount of ADH
2. osmolarity of medulla interstitum from countercurrent mulitplier mechanism in loop of henle of juxtaglomerular nephrons and countercurrent exchanges in the vasarecta |
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Term
| countercurrent exchange mechanisms occur in the vasarecta or peritubular cappilaries? |
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Definition
| vasarecta. Here there is almost no change in blood osmolarity entering or leaving the medulla. Blood flow in vasa recta is low. All of this is in the medulla and refers to juxtaglomerular nephrons. |
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Term
| erythropoeietin secreted from the ___arterioles of the kidney |
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Definition
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Term
| which adrenal disease will decrease aldosterone? Which adrenal disease will increase aldosterone? |
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Definition
| addison's is autoimmune destruction of the adrenal gland resulting in decrease aldosterone secretion while cushing's disease is excess glucocorticoid and subsequently some extra aldosterone release. |
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Term
| what nerve senses stretch in the stomach and then causes contraction of ____ muslces? |
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Definition
| pelvic nerve senses stretch in stomach and innervates parasympathetic nervous system to cause detrusor muscle contraction |
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Term
| external bladder sphincter controlled by? |
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Definition
| pudendal nerve. Pudendal nerve to external sphincter under voluntary control causes skeletal muscle relaxation |
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Term
| the most important buffer intracellular is bicarb ? or proteins? or phosphate? |
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Definition
| proteins!!!pKa is near 7.4. Proteins include albumin and globulin |
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Term
| where can you find carbonic anhydrase? |
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Definition
1. lungs
2. hemoglobin
3. epithelial cells |
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Term
| phosphate is more common in the intracellular or extracellular space? |
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Definition
|
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Term
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Definition
|
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Term
| explain phosphate buffer system in the urine |
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Definition
| out of the plasma filtrated 80% of phosphate is reabsorbed at the proximal tubules. The rest continues through the nephron and acts as hydrogen acceptors which allows for HCO3 to continue to be produced. |
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Term
| NH4 transported to tubule lumen by Na counter transport |
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Definition
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Term
| If pH is 7.4 then the ratio of HCO3 to PCO2 is? |
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Definition
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Term
| does alkalosis or acidosis cause over excitability of nervous system and tetany |
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Definition
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Term
| it takes how many days for full effect of renal compensation? |
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Definition
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Term
| what kind of diseases result in loss of base and therefore metabolic acidosis? |
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Definition
renal tubular acidosis
diarrhea and loss of HCO3 |
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Term
| excess aldosterone will cause metabolic acidosis or acidosis? What happens.. |
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Definition
| Metabolic alkalosis. increase reabsorption of Na and HCO3 while loss of H cations |
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Term
| purpose clinically of using anion gap? |
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Definition
| allows for differential diagnosis. A person in metabolic acidosis from renal failure will have an inc anion gap while a person in metabolic acidosis from diarrhea will not have an anion gap that is elevated. |
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Term
| most common culprit for increase anion gaps from organic acids? |
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Definition
| organic acids such as lactate and ketones |
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Term
| most common culprits for increasing anion gaps from inorganic acids |
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Definition
| chronic renal failure and accumulation of inorganic acids such as HSO4 and HPO4 |
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Term
| a decrease in anion gap is not normal but perhaps may be from? |
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Definition
| hypocalcemia or hypomagnesium |
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Term
| Normally the unmeasured ___ are more than the unmeasured ______ |
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Definition
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Term
| what is the total body water for females compared to males. Why? |
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Definition
| Females have more fat than men so they have less water. Females have approximately 50% of their body weight is water while men its 60% or 42 liters. |
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Term
| The fastest response to low BP is via? |
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Definition
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Term
| decrease blood volume stimulates ____ receptors while decrease blood pressure stimulates ______ receptors |
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Definition
decrease blood volume --> cardiopulmonary receptors.
2. Decrease blood pressure ---> baroreceptors |
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Term
| strong sympathetic response will effect the kidney how? |
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Definition
1. constriction of afferent and causes decrease GFR and RBF and decrease Na so body can hold onto fluid to maintain pressure
2. Increase Na reabsorption via alpha adrenergic receptors increasing Na/K and Na/H pumps
3. increases renin release. |
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Term
| What does ANP do to periphery and what does it do to epi and NE production |
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Definition
| It decreases Epi and NE production and causes vasodilation of periphery. (opposite of symp) |
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