Human excretory system performs a function of removing the waste from human body. Human excretory system is made up of specialized structures and capillary networks that are used to assist in the excretory process. It includes kidneys and their function unit that is known as a nephron. The excretory activity performed by the kidneys is regulated by specialized hormones that modulate the absorption within nephron.
Defecation is removal of the waste residue from the body. Excretion is the process through which metabolic waste which is not useful for the body is removed in the form of urine, sweat, or stool.
Even lungs are a part of human excretory system. Lung excretes metabolic waste in the form of CO2 and H2O gas. Liver produces bile which in turn secretes cholesterol, bilirubin pigmen and biliverdin. This provides colour to the feces and the stool produced.
Skin produces sweat and is hence known to be an excretory organ. Skin controls the body temperature as the produced sweat absorbs body heat. Skin also shields the body from the physical damage, germs, drought, light and evaporation etc. Skin can also feel the slight touch, pressure and the outside temperature.
Sweat is made up of water. The process of removal of sweat in the form of water vapors from our skin is known as perspiration. Sweat consists of water, salt, urea and solutes.
Emotional matters or excessive load can cause stress which in turn makes the skin sweat. Example, even the palms get sweaty while under emotional stress.
They are bean shaped organs that are located on either side of the backbone at the level of stomach and liver. Renal arteries allow the blood to enter the kidney while blood leaves from renal veins.
Ureters (tubes) carry the waste products from kidneys to the urinary bladder for release or storage. Kidneys’ by-product is urine that is water like solution containing waste products, salts, organic compounds, uric acid and urea.
FUNCTIONS OF KIDNEYS
- Kidneys remove nitrogenous waste urea from blood.
- Kidneys remove excess of water from body.
- Kidneys maintain proper pH of blood by removing the excess of acids and bases from blood.
- Kidneys maintain proper balance of concentration of salts in blood.
- Kidneys remove other toxic substances from blood like urea, uric acid and ammonia.
- It maintains volume of extracellular fluid.