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Excretion - Coggle Diagram

- - - - nephrons
        
        responsible for urine formation
        
        structure of nephron
        
        bowman capsule
        
        proximal convoluted tubule
        
        glomerulus (a network of capillaries)
        
        loop of henle
        
        distal convoluted tubule
      - medulla
        
        holds the renal pyramids
      - renal pyramid
        
        contains nephrons
      - renal pelvis
        
        enlarged portion of ureter in the kidneys
- - - - mostly due to home conditions: not ideal or clean enough
      - also need a lot of bags of fluid
      - expensive+ tedious
  - - - external cleanse
      - arteriovenous fistular/graft
      - vascular abso-?
      - dialysate
    - - blood drawn thru a fistula
      - blood is passed through a dialyser
      - dialysis fluid in contact with tbig carrying patients blood, diffusion of waste materials fro blood into surrounding fluids
      - small molecules like urea and metabolic waste products diffuse out of the tubing into dialysis fluid, blood cells platelets and large molecules remain in the tubing
      - blood is then returned into a vein in patients arm
      - dialyser
        
        long narrow tubing to increase SA to vol ratio, speed up rate of diffusion between blood and dialysis fluid
        
        blood flow direction opposite to dialysis fluid flow, maintains concentration gradient for waste products removal
      - dialysis fluid
        
        same concentration of essential substances as healthy blood so essential substances will not diffuse out of blood into dialysis fluid
        
        if person is lacking, then substances can diffuse into patients blood
        
        does not contain waste products like urea, so waste products will diffuse out of the tubing into dialysis fluid down a conc gradient
  - - - diabetic need insulin or meds, dialysis only for diabetes people with kidney failure. diabetes just increase risk
- - - - excreted by lungs as gas in expired air
    - - excreted by kidneys/skin as urine and sweat
    - - excreted by kidneys, skin and lungs in urine, sweat and water vapour in expired air
    - - from liver excreted in shit
- - - - blood pressure fforces fluid from glomerulus into the lumen of bowmas capsule
      - capillaries and specialized cells of bowmanns capsule allow water and small solutes to pass through the bowman's capsule
      - blood cells and large molecules and plasma proteins stay in the bloodstream
    - - renal artery splits into nurmourse afferent arterioles, each leading into a nephron. The arteriole splits into the glomerulus
      - 2.the lumen of the afferent arteriole that brings blood into the glomerulus is wider than the efferent arteriole that brings blood away
      - blood enters the glomerulus more readily through wider afferent arteriole than it leaves through the narrower efferent arteriole
        
        blood damns up in the glomerulus, creating high blood pressure
        
        main force for ultrafiltration to happen
      - the pressure forces blood plasma out of the glomerular capillaries into the bowman's capsule along the entire length of the glomerulus
      - Blood plasma forced out contains water and small molecules (glucose, amino acids, minerals and nitrogenous products) and forms glomerular filtrate in the bowman's capsule
      - Blood cells, platelets, ad large molecules such as blood proteins and fats remain in the blood and leave the glomerulus via the efferent arteriole
  - - - useful solutes (e.g glucose vitamin amino acids salts) absorbed back through facilitated diffusion or active transport
      - water absorbed back through osmosis
    - - most reabsorption of useful substances are completed at proximal convoluted tubule
        
        healthy: all glucose, vitamins, amino acids reabsorbed through walls of nephron into surrounding capillaries
      - 85% of sodium ions , chloride ions and water are readsorbed, active uptake of sodium and other ions into the blood increase water potential in the nephron, causing water to leave nephron by osmosis
      - some water and ions are reabsorbed back at the loop of henle
      - water and a smaller concentration of sodium ions and chloride ions are reabsorbed at the distal convoluted tubule
      - remaining water as required by body is reabsorbed at collecting duct
- - - - break up complex molecules into simpler molecules
      - examples
        
        hydrolysis (digestion in alimentary canal)
        
        respiration (glucose broken down to release energy, produces H2O+CO2)
        
        deamination (excess amino acids deaminated in the liver to produce urea)
    - - build up simpler molecules into complex molecules
      - examples
        
        condensation reaction (synthesis of protein from amino acids)
        
        photosynthesis (CO2 is reduced to glucose in presence of H2O and sunlight)