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functions of renal system
- Production of Urine
- Indirect Regulation of Interstitial Fluid
- Endocrine Function: (RBC production & regulation of bp)
- Activation of Vitamin D
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Production of urine regulates plasma __
- ionic composition
- volume
- osmolarity (solute concentration)
- pH (H+ concentration)
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Plasma volume is regulated by __
controlling water excretion (has a direct effect on blood pressure)
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Plasma osmolarity is regulated by __
controlling the rate of water excretion, the kidneys regulate the concentration of solutes relative to water in the plasma
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metabolic waste products and foreign substances that are removed during excretion
- urea and uric acid
- food additives
- drugs
- pesticides
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Urea and uric acid are generated by __
protein and nucleic acid catabolism
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Since __ is derived from plasma, regulation of plasma will affect the composition of __
interstitial fluid
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stimulates RBC production
Erythropoietin
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involved in the regulation of blood pressure
Angiotensin II
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__ converts to __ (active vitamin D)
calcidiol; calcitriol
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Vitamin D is necessary for __
regulating calcium and phosphate levels in the blood
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Glomerular filtration is driven by __
hydrostatic and osmotic pressure
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glomerular hydrostatic pressure
pressure of plasma due to blood pressure. (PGC) = 60mmHg
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glomerular osmotic pressure
due to osmotic gradient (PBC)
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Overall, glomerular filtration pressure is __, favoring its movement __
16mmHg; out of the capillary and into Bowman’s capsule
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The volume of glomerular filtrate produced is __ per __
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The filtrate enters the __
kidney tubules
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The body’s average plasma volume is about __ in an adult
2.75L
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The total plasma volume filters through the kidneys every __
22 min
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Intrinsic Control/Regulation of GFR
- Myogenic regulation
- Tubuloglomerular feedback
- Mesangial cell contraction
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Stretching of smooth muscle of afferent arteriole causes constriction
Myogenic regulation
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Macula densa secretes paracrines in response to changes in GFR which cause either contraction or relaxation of afferent arteriole
Tubuloglomerular feedback
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Cells contract in response to stretching, decreasing surface area of capillaries, reducing GFR
Mesangial cell contraction
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Extrinsic Control/Regulation of GFR
A drop in Mean Arterial Pressure (MAP)
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A drop in Mean Arterial Pressure (MAP) is due to __, causes a __ in GFR
hemorrhage or sweating; drop
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A drop in MAP activates the __ which trigger __. This increases __ & decreases __
sympathetic nervous system; smooth muscle contraction of afferent and efferent arterioles; renal vascular resistance; urine production and water loss
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__ % of filtrate is reabsorbed
- 98-99
- - actively & passively
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Most solutes are reabsorbed by the __
Proximal (mostly) & distal convoluted tubules
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Solutes that are reabsorbed create an __ gradient for the __ reabsorption of water
- osmotic; passive
- - Water follows salt
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hormones involved in reabsorption
aldosterone & ADH
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Transport Maximum: Some molecules that are reabsorbed require __
carrier proteins (facilitated diffusion): such as glucose
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Transport maximum: The number of __ determines the maximum quantity of __ that can be transported across the __
carrier proteins; a particular molecule; renal tubule membrane
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If the concentration of molecules exceeds the number of carriers __
Some of the molecules will not be reabsorbed but end up in the urine
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During secretion, molecules move from plasma of __ to the __
peritubular capillaries; renal tubules
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During secretion, movement of molecules is the same as molecules of reabsorption except __
in the reverse direction
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