A2 biology excreation

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Excreation basic notes btw sorry for any spelling mistakes i cant tell somtimes cause i am dislexic 

The liver 

  • it is the center of many metabolic reactions in the body. 
  • the liver is split up ino sections called chambers that sorround the heptatic vein.  these are chabers of the liver  (http://o.quizlet.com/i/kRenfjUlmAzmEmgeJyTFNw_m.jpg)                      
  • These chambers are futher split up into lobles, these have the portal vein and portal atery running through them withliver cells surronding them allowing form mximum contact with the blood.
  • (http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/Image488.gif)
  • The cells surrounding the blood vessils have many villi and micro villi these are used to increse their surfcace area.
  • The kampfer cells are used to break down any old red blood cells 
  • The bile duct produces bile salts used as emusifires to aid enzymes in breaking down food in digestion.

The liver and deammination 

  • This occurs when their are protine rich diets. when their is excess protine it is broken down in the liver by a process called deamination. 
  • excess amino acids are broken down by a hydrolysis reaction 
  • This reaction is as follows: NH2CHRCOOH + H2O =====> NH3 + O=CRCOOH

The orthine cycel 

  • Ammonia a product of deammination is highly toxic as such it needs to be diluted or converted into something less toxic. the orthine cycel achives this 

The kidney why we need it?

  • the kidney is a bean shaped organ it is where urine is made one of the main productas that needs to be excreted from the body the other being carbon dioxide
  • carbon dioxide
  • this needs to be excreted as it can reduce heamaglobin's affinty for oxgen this will mean their will be less oxgne forr respireing cells 
  • itt can also lower the pH of the bblood as it can react with water to make carbonic acid 
  • as such it needs to be excreted by the body 
  • ammonia
  • is highly toxic to the humman body so it needs to be diluted into urea 
  • the urea can be toxic as well if allowed to build up as such it also needs to be excreted 

the structure of the kidney 

  • the  kidney has a outer layer that surounds it called the renal capsual 
  • inside the capsual is the renal cortex 
  • bellow the cortex is a darker layer of tissue called the renal medula
  • the medula is then connected to the renal pelvis by pyraminds


the nephron

  • this is the part of the kidney that is resonsael for the production of urine
  • the first step of makeing urine occurs in the bowmans capsual a blood vessil called the glourous the shape of the capsuals narrow entrance causes the blood to come in at high pressure 
  • this cause all small molucues to be forced out the blood vessils in a fluid form an molcules that are smaller than 69,000 dimers are then abel to pass the basment mebrane and enter the bowmans capsual 
  • the podcutes have finger like prtusions to makes space in the cells to allow the small molcules and


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