We know about the main excretory organs, the kidneys, urinary bladder etc. But did you know even Lungs are an excretory organ? And so are salivary glands. Surprised? Well, read on to know more about the role of other excretory organs in our bodies.
We have learnt about the excretory system in the body which is responsible for eliminating wastes and toxins from our body by the process of excretion. The excretory system primarily comprises of a pair of kidneys, a pair of ureters, the urinary bladder and the urethra. These together, along with chemical and hormonal regulation, help maintain homeostasis in the body. However, there are other organs who also perform excretion along with the excretory system. Let us learn more about the role of the other organs in excretion.
Browse more Topics under Excretory Products
- Introduction to Excretory System
- Human Excretory System
- Urine Formation
- Regulation of Excretion
- Disorders of the Excretory System
Other Excretory Organs
Let us now take a look at the various other organs involved in our excretory system.
The skin is the largest organ in our body. Its primary functions include regulation of body temperature, protects the body from harmful pathogens, protects the body from sunlight and harsh environmental conditions and provides the support to the mechanical framework of bones and muscles.
The skin contains multiple layers. These layers of the skin contain two types of glands: sweat glands and sebaceous glands. The sweat glands function to produce sweat. Also, sweat is a secretion of these glands which contains NaCl, water, amino acids, and glucose. The secretion of the sebaceous glands is known as sebum and it is a way to excrete excess fats such as sterols and waxes.
Lungs are the primary organs of respiration in humans. They facilitate gaseous exchange where oxygen is taken in whereas carbon dioxide is given out. Therefore, lungs help in expelling or eliminating carbon dioxide which is a waste substance for the body. Along with carbon dioxide, the lungs also give out water in the form of water vapour. The lungs eliminate around 18L of carbon dioxide per hour and 400ml of water as vapour per day.
The amount of water eliminated as vapour through the lungs depends upon the temperature of the environment and condition of the body. In cases where the water levels in the body are less, the amount of water vapour eliminated is also reduced.
Intestines and the GI tract
Apart from urine, another waste that is eliminated from the body is faeces. Faeces is the solid waste that the body eliminates via the rectum. The digestive system and primarily the intestines are responsible for the formation of faeces. Excess fibre, salts, glucose and minerals like calcium and iron are eliminated through faeces.
The liver plays a vital role in the formation and elimination of urea. This urea is then transported to the kidneys for elimination. The liver is known as the ‘graveyard of RBCs’ as it is here that they are destroyed. The by-products of RBC destruction, metabolized drug by-products, and hormonal metabolites are all synthesized in the liver and poured into the bile. Bile is then carried forward to the intestines which eliminate these wastes through faeces.
The main function of these glands is to secrete saliva. Saliva is a watery secretion that contains enzymes which help to digest the food as soon as it enters the oral cavity. Salivary glands are believed to take part in the excretion of heavy metal ions like mercury and lead.
Solved Example for You
Q: Which of the following is not an excretory organ?
(a) Lungs (b) Skin
(c) Intestine (d) Appendix
Sol. (d) Appendix. The appendix is a vestigial organ that has no role to play in excretion.