Accessory Excretory Organs-Role of other organs in human excretion

In human being other than the kidneys, lungs, liver and skin also help in the elimination of excretory wastes.These organs are called accessory excretory organs.

1.Lungs:Human lungs remove large amounts of carbondioxide (18 litres/day) and also significant quantities of water every day.

2.Liver :Liver, the largest gland in human body. It secretes bile which contains substances like bilirubin, biliverdin, cholesterol, degraded

steroid hormones, vitamins and drugs. Most of these substances ultimately pass out alongwith digestive wastes.

3.Skin:The sweat and sebaceous glands in the skin can eliminate certain substance through their secretions.Sweat produced by the sweat glands is a watery fluid containing NaCl, small amounts of urea, lactic acid, etc. though

the  majir role of sweat is to facilitate a cooling effect on the body surface.Sebaceous glands eliminate certain substances like sterols, hydrocarbons and waxes through sebum. This secretion

provides a protective oily covering for the skin.

4.Intestine:Epithelial lining cells of colon excrete excess salts of calcium, magnesium and iron along with faeces.

5.Salivary glands: Certain  heavy metals and drugs are eliminated through saliva.