Term
What is the glomerular filtration rate |
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Definition
the amount of filtrate produce each minute |
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Term
How much filtrate is produced daily |
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Definition
about 150-180 Liters a day |
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Term
What percentage of filtrate is reabsorbed |
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Definition
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Term
How much urine is excreted daily |
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Definition
between one and two liters |
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Term
What can affect the glomerular filtration rate |
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Definition
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Term
What two processes regulate glomerular filtration rate |
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Definition
adjusting blood flow into and out of the glomerulus and adjusting the glomerular surface area available for filtration |
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Term
What are the three ways in which GFR can be regulated |
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Definition
through renal autoregulation, hormonal regulation, and neural regulation |
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Term
What are the two types of renal autoregulation of GFR |
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Definition
myogenic mechanism and tubuloglomerular feedback |
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Term
What does the myogenic mechanism accomplish |
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Definition
it counters changes in blood pressure by changing blood vessel diameter |
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Term
How does the myogenic complex deal with an increase in blood pressure |
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Definition
it causes constriction of afferent arterioles which allows less blood to flow through which decreases filtration |
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Term
How does the myogenic complex counter a decrease in blood pressure |
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Definition
it causes dilation of afferent arterioles which increases blood flow and increases filtration |
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Term
What is the general function of the myogenic mechanism |
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Definition
to stabalize the GFR even when there are changes in blood pressure |
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Term
What is the general function of tubuloglomerular feedback |
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Definition
its a way to ensure that filtration is not occuring too quickly |
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Term
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Definition
specialized cells in the distal convoluted tubule that detect elevated levels of solutes and water in the filtrate |
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Term
What do the macula densa do when they detect elevated levels of water and solutes in the filtrate |
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Definition
they send signals that stop nitric oxide release which causes afferent arterioles to contract which slows the flow of blood and slows filtration |
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Term
What division of the nervous system regulates GFR |
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Definition
sympathetic division of the autonomic nervous system |
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Term
What does activation of the sympathetic nervous sytem do |
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Definition
causes widespread vasoconstriction which decreases GFR |
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Term
What can happen as a result of extreme exertion or stress |
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Definition
The extended rerouting of blood flow can cause hypoxia, metabolic waste build up, proteinuria, hematuria, and renal failure |
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Term
Why would metabolic waste build up during times of extreme stress or exertion |
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Definition
blood flow is rerouted and vasoconstriction occurs due to sympathetic stimulation, this causes less filtration which means less removal of wastes through urine |
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Term
Why can proteinuria,hematuria,or renal failure occur as a result of extreme stress or exertion |
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Definition
redirected blood flow and vasoconstriction due to sympathetic stimulation can cause hypoxia of renal cells which causes damage to filtration membrane allowing substances that normally can not get through to enter the urine |
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Term
When is angiotensin II released |
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Definition
when blood pressure is low |
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Term
What does angiotensin II do |
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Definition
it causes vasoconstriction of afferent and efferent arterioles |
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Term
What hormones regulate glomerular filtration rate |
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Definition
angiotensin II and atrial natriuretic peptide |
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Term
How does angiotensin II regulate GFR and blood pressure |
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Definition
it causes vasoconstriction which decreases blood flow and decreases filtration. This means less water is lost from the kidneys which means an increase in blood volume and an increase in blood pressure |
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Term
When is atrial natriuretic peptide released |
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Definition
in response to high blood volume and high blood pressure |
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Term
What does atrial natriuretic peptide cause |
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Definition
caused dilation of glomerular capillaries and increases the surface area available for filtration |
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Term
what hormone increases the surface available for filtration |
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Definition
atrial natriuretic peptide |
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Term
How does atrial natriuretic peptide affect GFR |
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Definition
it increases it which causes more filtration more urine which means less blood volume and lower blood pressure |
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Term
What is transcellular reabsorption |
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Definition
filtrate flows through the tubalar cell to get to the capillaries |
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Term
What transport systems are used in tubular reabsorption and tubular secretion |
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Definition
active transport, secondary active transport, facultative water reabsorption, obligatory water reabsorption |
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Term
What is obligatory water reabsorption |
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Definition
water is obliged to follow its osmotic gradient towards a higher solute concentration |
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Term
What is facultative water reabsortion |
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Definition
need based reabsorptiom using water channels |
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Term
What is facultative water reabsorption regulated by |
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Definition
antidiuretic hormone which cause more reabsorption |
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Term
What is the transport maximum |
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Definition
the number of carrier proteins determines how much of a substance can be transported |
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Term
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Definition
sugar in urine, normal after a carb rich meal, may be an indicator of diabetes mellitus |
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Term
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Definition
amino acids in urine. Normal after a protein rich meal |
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Term
Which vitamins are excreted in the urine |
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Definition
excess b vitamins and vitamin c |
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Term
What part of a nephron reabsorbs the most filtrate |
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Definition
the proximal convoluted tubule |
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Term
What is reabsorbed in the proximal convoluted tubule |
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Definition
most organic compounds, water, and ions |
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Term
What is secreted in the proximal convoluted tubule |
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Definition
H+ ions in exchange for Na+ ions |
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Term
What does the secretion of H+ in the proximal convoluted tubule help to regulate |
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Definition
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Term
What is the descending limb of the loop of Henle permeable to |
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Definition
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Term
What is the ascending limb of the loop of Henle permeable to |
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Definition
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Term
What makes the descending limb of the loop of Henle permeable to water |
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Definition
the prescence of aquaporin I, a water channel |
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Term
What ions are actively transported out of the tubular fluid in the distal convoluted tubule |
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Definition
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Term
What regulates the reabsorption of calcium in the distal convoluted tubule |
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Definition
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Term
Where do collecting ducts collect tubular fluid from |
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Definition
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Term
Where do collectind ducts transport tubular fluid to |
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Definition
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Term
What substances are reabsorbed in the collecting duct |
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Definition
water, sodium ions, bicarbonate ions, urea |
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Term
What controls the reabsorption of most substances in the collecting duct |
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Definition
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Term
What substance is both reabsorbed and secreted in the collecting duct |
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Definition
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Term
What substance is secreted in the collecting duct |
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Definition
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Term
How does aldosterone regulate the reabsorption of sodium in the collecting duct |
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Definition
it increases na+ reabsorption which increases bv and bp |
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Term
What hormones regulate tubular reabsorption and tubular secretion |
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Definition
angiotensin II, antidiuretic hormone, atrial natriuretic peptide |
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Term
What does angiotensin II stimulate |
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Definition
the reabsorption of sodium ions, chloride ions, and water as well as the release of aldosterone |
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Term
What does aldosterone stimulate |
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Definition
reabsorption of sodium ions and chloride ions as well as the secretion of potassium ions |
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Term
How does ADH cause increased retention of water |
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Definition
increases water permeability of collecting duct by opening water channels called aquaporin II |
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Term
How does the secretion of ADH affect urine concentration |
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Definition
it causes the urine to be more concentrated |
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Term
What hormones does atrial natriuretic peptide suppress |
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Definition
aldosterone and antidiuretic hormone |
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Term
How does atrial natriuretic peptide affect tubular secretion |
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Definition
it increases the secretion of sodium ions which leads to a decrease in blood volume and blood pressure |
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