Kideny
- Created by: Emilyburkee
- Created on: 22-05-22 12:12
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- The Kidney
- structure
- simple
- cortex, helieum and the nephron
- the nephron
- is the functional unit of the kidney
- renal corpuscle = bowman's capsule and golmerus
- role = filtration
- renal tubules= PCT and loop of henel
- role = reabsorbtion
- collecting duct
- PCT
- 80% reabsorbed
- reabsorption of nacl ect and regulation of PH
- na
- antiporters
- transported with K into cell from blood
- transported with H+ into tubule
- antiporters
- Glucose
- symporters
- with NA
- has a max rate as transporters can be saturated
- with NA
- symporters
- simple
- GFR
- amount of filtrate filtered across golmerus to BC per min
- normal = 125ml/min
- factors effecting
- filtration barrier - made up of podcytes
- volumes and pressure
- if vas resistance increases in the aff arterioles = less Bf into golmerus = decrease GFR
- if Vas res increases in eff arterioles = more RBF in glomerus and higher pressure in golmerus = higher GFR
- methods for estimation
- creatine
- measure filtration of a substance
- must be freely filtered
- not secreted ect by the kidney
- present a stable concentrations in plasma
- inert
- control
- autoregulation
- myogenic= osmatic changes
- tubulargolmera feedback
- GFR increases- detected , paracrine, aff arteriole constricts and decreases GFR
- sympathetic nerves inv in stress responses
- nervous - sympathetic and noradrenaline
- hormonal - agngeotenisn
- autoregulation
- amount of filtrate filtered across golmerus to BC per min
- control of osmolarity
- as filtrate moves down loop of henel = more concentrated as water is removed
- counter current system
- solutes punped out in asending limb - hypoosmotic
- if the collecting duct = permeable to water the urine becomes more concentrated as water moves out
- ADH controls osmolarity of collecting duct
- thrist mechanicm
- dry mouth, increase in osmolarity, decrease in bv and BP
- stimulates thirst center in hypothalamus
- dry mouth, increase in osmolarity, decrease in bv and BP
- as filtrate moves down loop of henel = more concentrated as water is removed
- regulating blood composition
- ADH
- osmoreceptors detect an increase in osmolarity
- stimulates ADH relase form posterior pituitary gland
- travels in blood to kidney = increase number of water channels open
- decrease osmolarity
- PH
- H+ buffer system = co2+H2o - H+ +hco3-
- increase in co2 = shidt to right
- renal mechanism
- nephrone secretes H+ into lumen - combines with Hco3 making Co2 and water
- Co2 diffuses back into cell - + water back to H+ and hco3
- H+ secreted again and hco3 = reabsobed with NA
- H+ = extreted with Nh4
- H+ secreted again and hco3 = reabsobed with NA
- Co2 diffuses back into cell - + water back to H+ and hco3
- nephrone secretes H+ into lumen - combines with Hco3 making Co2 and water
- H+ buffer system = co2+H2o - H+ +hco3-
- Blood volume
- RAAS
- dehydration of na+ deficency stimulates
- rennin released and cleaves angeotensinogen into angeotensin 1
- travels to lungs where ACE converts it to agngeotensin 2
- vasoconstriction increasing BP or
- stimulates relase of aldosterone which increases NA retension = increasing water reabsorption increasing BV
- vasoconstriction increasing BP or
- travels to lungs where ACE converts it to agngeotensin 2
- rennin released and cleaves angeotensinogen into angeotensin 1
- dehydration of na+ deficency stimulates
- RAAS
- Sympathetic nerves innervate afferent and efferent arterioles as well as cells of the nephron. ? Sympathetic activity is increased as part of the efferent arm of the baroreceptor reflex
- ADH
- ? Erythropoietin ? Production stimulated by decrease in PO2 ? Produced in interstitial cells in the kidney ? Stimulates erythrocyte production through differentiation of CFU-E into proerythroblast. ? Calcitriol ? Active form of vitamin D ? Produced by hydrolysis from stored forms released from the liver ? Essential in maintenance of calcium uptake from the GI tract.
- Bladder
- Filling
- 2 uters - wave of peristalsis =pushes urine down
- parasympathetic = inactive
- sympathetic = active and keep relax
- Pudendal nerve fibres from sacral segments maintain closure of the external sphincter- active
- Micturition:
- Parasympathetic nerves are now active, ? they release acetylcholine and the bladder contracts ? they relax the outflow tract
- ?Sympathetic nerves are now inactive ?Pudendal nerve fibres are less active and the external sphincter open
- Filling
- structure
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