What is Excretion?
Excretion is the physiological process of elimination of metabolic waste from the body. This process is strictly found only in animals. The excretory products include amino acids, urea, uric acid, carbon dioxide, water, and ammonia.
Some Molluscs and Echinoderms excrete waste products from the body in the form of amino acids. Ammonia is the primary excretory product in animals, it is derived from the proteins present in the food we eat. It is the most toxic nitrogenous waste and is excreted by diffusion by most of the amphibians and aquatic animals.
Mammals excrete nitrogenous waste as urea. It is less toxic and comparatively less soluble in water. Birds and reptiles excrete nitrogenous waste as uric acid.
Also Read: Excretion And Its Importance
Let us have a detailed look at the different excretory products and their elimination in different organisms.
Excretory Products of Different Organisms
The excretory products and organs of different organisms are mentioned below:
|Organisms||Excretory Products||Excretory Organs|
|Hydra||Ammonia||General body surface|
|Periplaneta||Uric acid||Malpighian tubule|
|Palaemon||Uric acid||Antennary gland|
|Spider||Uric acid||Coxal glands, Malpighia tubule|
|Leucon||Ammonia||General body surface|
Human Excretory Organs
The human excretory system comprises of the following excretory organs:
- A pair of kidneys
- A pair of ureters
- Urinary Bladder
Also Read: Human Excretory System
These are the primary excretory organs in humans located on the left and right side of the spine, near the liver. They are divided into the renal cortex, renal medulla, and renal pelvis. Renal pelvis carries urine from the kidney to the ureter. A nephron is the functional unit of a kidney.
Also Refer: Regulation Of Kidney Function
It is a thin tube that comes out of each kidney carrying urine to the urinary bladder.
It is a sac-like structure that stores urine until micturition. The Process Of Urination or expelling urine from the body.
It is a tube-like structure that extends from the urinary bladder and helps in expelling urine outside the body. It is usually shorter in females and longer in males.
Also Read: Disorders of the Excretory System
Other Excretory Organs
Besides the above mentioned excretory organs, humans have other excretory organs as well. These excretory organs include:
Skin is known to be the largest organ in the human body. It contains sweat glands and the sebaceous glands. The sweat glands produce sweat which contains sodium chloride, amino acids, water, and glucose. The sebaceous glands excrete excess fat such as sterol and wax.
Also Refer: Structure And Functions Of Skin
Lungs facilitate gaseous exchange. They help in inhaling oxygen and eliminating carbon dioxide and water vapour from the body.
Around 18L of carbon dioxide per hour and 400ml water per day is eliminated from the body.
These glands participate in the excretion of heavy metal ions such as lead and mercury.
Gastrointestinal tract and Intestines
The intestines eliminate the nitrogenous waste in the form of faeces. Salts, glucose, calcium, iron, fibre is excreted through faeces.
Also Read: Gastrointestinal tract
This was brief information related to Excretory Products and their Elimination. Learn more in detail about Excretion, its producst and other related topics @ BYJU’S Biology