Excretion System in Human
Excretory system is discharging process of waste matters that aren’t required by the body. Human excretory system consist of excretory organs as the throwing place of those waste matters. Excretory organs involve liver, lung, kidney and skin.
Liver is included into gland and the largest gland inside the body. Liver has reddish-brown color of weight in adult people is about 2 kg. Liver is located inside abdominal cavity to the right, under diaphragm.
Liver is included into secretory organ because the liver produce gall, while liver is called excretory organ because the gall discharged contains waste matters that come from broken red blood cell and destroyed in the lymph. The gall discharged by liver is received in gallbladder and then is flown to duodenum by gall duct.
The functions of liver:
- Destroying disease germs and neutralizing poison that enters into the body
- Controlling sugar level in the blood.
- As formation place of prothrombin and fibrinogen
- As place to change pro-vitamin A to be vitamin A
- As formation place of urea
Lungs are main organ in respiratory system because it functions to take oxygen. Besides that, the lung also has function as excretion organ. Respiratory process produces energy and by product of waste matter that is carbon dioxide (CO2) and water vapor (H2O). CO2 and H2O are released again through lung.
Kidney is main excretory organ in humans. Human kidney is one pair, shaped like kidney bean and has red color or purplish. The length of kidney is about 10 cm, and lies inside abdominal cavity to the right-left of vertebral column. Left kidney is higher than right kidney. The weight of kidney of adult people is about 200 grams
The functions of kidney:
- Filtering blood
- Keep water equilibrium inside the body
In normal condition urine contains:
- water of 95%
- urea, uric acid and ammonia that is waste of restore of protein
- the gill pigments (bilirubin and biliverdin) that give yellow color in urine
- excessive matters in blood (vitamin B and C, drugs, poison, and hormone)
- various kinds of salt, particularly common salt (NaCl)