Excretion Test - 1

The urine of a man suffering from diabetes insipidus is tasteless and watery due to deficiency of Anti Diuretic Hormone.

Excretion is mainly responsible for the removal of waste products of the animal's own metabolism. In vertebrates this is primarily carried out by the lungs, kidneys and skin.

pH value of human urine is 6. Humans on average excrete 1.4 L of urine per person per day.

Urine production per day increases on cold damp day as blood supply to the skin is decreased and to internal organs is increased to preserve the internal heat,so with more blood supply more urine is produced.

Nitrogenous wastes are produced by the utilisation of proteins.They are further broke down to amino acids which undergo deamination to produce ammonia.It is the further converted to urea to be eliminated by kidneys.

Apart from excretion, kidneys also perform osmoregulation. It is the physiological processes that an organism uses to maintain water balance; that is, to compensate for water loss, avoid excess water gain, and maintain the proper osmotic concentration (osmolarity) of the body fluids.

Filtration of wastes from the blood in human body is carried out by kidney. Kidneys are essential to the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and regulation of blood pressure (via maintaining the salt and water balance).

The amount of renal filterate formed by kidney tubules in a day is about 160 litres.

The formation of nephric filterate in the glomerulus is a passive process , nonselective process in which hydrostatic pressure forces fluids through the glomerular membrane.

An opening through which arteries and veins enter or leave the kidney is called hilum.