A2 biology excreation
- Created by: Andrei stephen
- Created on: 17-09-14 18:46
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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 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.
- 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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