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48 Cards in this Set
- Front
- Back
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What are the 5 main functions of the kidneys |
1.regulaiton of BP via renin 2.regulation of rbc production 3. vit D activity 4.gluconeogenesis 5.volume and composition of internal environment |
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what is gluconeogenesis ? |
amino acids --> glucose |
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what is the role of the juxtaglomerular apparatus? |
autoregulation of glomerular filtration by tubulo-glomerular feedback (TGF) |
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What do JG cells secrete? |
renin |
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what do JG cells respond to? |
barorecpetors |
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what causes the release from renin? |
low pressure in afferent arteriole, low [NaCl] at macula densa, beta-adrenergic stimulatioln |
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How is angiotensinogen converted to Angiotensin 2? |
angiotensinogen is acted on by renin to produce ANG. ANG1 to ANG2 via ACE. |
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where does filtration happen? |
renal corpuscle |
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how are ions balanced ? |
the Donnan effect |
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what happens during ultrafiltration? |
it occurs at high pressure retention of glucose, aa's, water |
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what occurs in reabsorption? |
extraction of substances to go back into blood |
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what are the pores on the blood side of the basement membrane called? |
Fenestrae |
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what are the 4 forced in filtration (according to Starling's hypothesis) ? |
1. Hydrostatic pressure capillary 2. hydrostatic pressure interstitium 3. oncotic pressure capillary 4. oncotis pressure interstitium |
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what is the glomerular filtration rate? and how can this be calculted? |
total fluid filtered by all functioning nephrons GFR= NFP x Kf |
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what does the filtratrtion co-efficient depend upon? |
1. filtration area 2. hydraulic conductance |
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clinically what would you use to determine GFR? |
inulin |
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how do determine filtered load? |
GFR x plasma concentration |
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In the epithelium, what is the primary active transport? |
Sodium- potassium pump on basolateral membrane |
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In the epithelium what is the secondary mode of active transport? |
Sodium symports/antiports on apical membrane |
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what are the two types of tight junction? |
leaky or tight |
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what is bulk transport? |
all molecules dissolved in water pass through |
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what is the main Na/H antiport in the PCT? |
NHE3 |
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why have basal infoldings? |
increase surface area |
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what does carbonic anhydrase do? |
rapid interconversion of carbon dioxide and water to bicarbonate and protons |
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where is carbonic anhydrase found? |
microvilli on apical side in PCT cells |
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where does reabsorption of glucose occur? |
PCT |
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what is tubular max? |
max amount that can be reabsorbed by entire renal mass |
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What are the two cell types found in the Collecting duct? |
1. Principal cells 2. Intercalated cells |
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what are the two types of intercalated cells in the CD? |
1. A type 2. B type |
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Where are sodium pump located along the nephron? |
basolateral membrane |
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where along the nephron does 60-70% of Na reabsorption occur? what are the two transporters? |
- PCT 1. NHE3 2. SGLT 1 and 2 |
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where along the nephron does 20-30% of Na reabsorption occur? what two transporters are used ? |
TAL 1.NKCC2 2.NHE3
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what transporter does the DCT use fro NA reabsorption ? |
NCC |
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What type of cells in the CD assist in Na reabsorption? What transporter do they use? |
principal cells ENaC |
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what needs to be regenerated in those on a meat containing diet? |
Bicarbonate |
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what is the problem with a vegetarian diet? |
Too much bicarbonate |
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How does the body overcome having too much bicarbonate? |
Less protons secreted into PCT therefore more bicarbonate escapes reabsorption |
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what are the three locations where potassium is reabsorbed? |
PCT, TAL, distal tubule |
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what cell type reabsorbs potassium? |
Intercalated cells |
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what 4 things does potassium secretion cause? |
1. increase with cell [K] 2. increase urine flow rate 3. increase urine electronegativity 4. increase apical potassium permeability (ROMK) |
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What is aldosterone? what precursor is it converted from? Where is it released from? Why is it released? What is its function? |
steroid hormone cholesterol zona glomerulosa in adrenal gland - Increase in plasma [K], increase in plasma [ANG2], decrease plasma [Na] Regulation of plasma [K] |
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what is the mode of action for aldosterone? |
binds to MR1 in cytoplasm (protected by 11beta-HSD2). This increase mRNA therefore protein sy thesis. Must first cross membrane to reach MR1. |
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what is the early response of aldosterone? |
the Na permeability is increased and more ENaC made. This causes depolarisation and urin becomes more electronegative. more Na reabsorption and more K brought into cell. |
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what is the late response of aldosterone? |
increases cell [Na]. causes synthesis of apical K channels(ROMK) and Na pumps. |
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what does ANG2 bind to? What ion does it conserve? What ion reabsorption does it incease? |
AT1 receptors Na Na |
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What ion reabsorption is increased by noradrenaline? |
Na |
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Where is atrial natruiteric peptide (ANP) released from? |
right atrium by stretch |
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what does ANP inhibit? |
Na channels in CD |
