Outline and explain the various homeostatic functions of the liver in mammals.

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Deamination;  process  of  removal  of  an  amino  group  from  an  amino  acid  molecule;  the  process gets  rid  of  excess  amino  acids  in  the  body;  as  the  body  is  not  able  to  store  them;  the  amino  group enters  the  ornithine  cycle;  where  it  is  combined  with  carbon  (IV)  oxide  to  form  urea;  which  is excreted  in  urine  through  the  kidney;  Heat  production;  many  metabolic  activities  take  place  in the  liver;  releasing  heat  energy;  that  is  distributed  by  the  blood  to  other  parts  of  the  body;  this helps  in  thermoregulation;  Storage  of  vitamins  and  mineral  salts;  Vitamins  A,  B,  D,  E  and  K;  are stored  in  the  liver;  worn-out  red  blood  cells,  are  broken  down  to  yield  iron;  which  is  stored  in  the liver  in  form  of  ferritin;  this  is  used  later  in  case  of  shortage;  Formation  of  red  blood  cells;  occurs in  the  liver  of  the  foetus;  the  liver  also  breaks  down  old/exhausted  red  blood  cells;  leading  to formation  of  more  in  the  bone  marrow  to  replace  the  worn-out  cells;  to  enhance  oxygen  and carbon  (IV)  oxide  distribution;  Regulation  of  blood  sugar  level;  liver  cells  convert  excess glucose  into  glycogen  and  fats  under  the  influence  of  insulin  hormone;  the  stored  glycogen  is however  converted  back  to  glucose;  when  glucose  levels  are  low;  by  the  liver  cells;  under  the influence  of  glucagon  hormone;  Regulation  of  plasma  proteins;  plasma  proteins  such  as prothrombin  and  fibrinogen  are  manufactured  in  the  liver  using  the  amino  acids  found  in  the liver;  they  play  a  major  role  in  blood  clotting;  that  prevents  excessive  blood  loss  and  infection  at the  injured  area;  other  plasma  proteins  produced  by  the  liver  such  as  serum  and  albumen; contribute  to  the  maintenance  of  osmotic  pressure  in  the  body;  non-essential  amino  acids  are  also synthesized  by  the  liver;  for  use  by  the  body;  Storage  of  blood;  the  liver  is  highly  vascularised; hence  it  is  capable  of  holding  a  large  volume  of  blood  when  the  blood  vessels  dilate  during  hot conditions;  when  the  temperatures  are  low,  the  blood  vessels  constrict  under  the  influence  of  the endocrine  and  nervous  systems;  hence  less  blood  is  stored  in  the  liver;  this  contributes  to thermoregulation;  Detoxification;  this  is  the  process  where  harmful  compounds  such  as  drugs and  poisons;  are  converted  to  less  toxic  compounds  in  the  liver;  toxicity  is  caused  by  medication, drugs  and  microorganisms;  the  toxic  compounds  are  later  excreted  in  urine;  detoxification prevents  the  accumulation  of  toxins  in  body  cells;  which  could  lead  to  death  or  malfunctioning  of the  body  cells;  Max.  20  mks 

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