Excretion

Excretion is the process by which animals eliminate waste materials and nitrogenous metabolic by-products. Organisms maintain acid-base balance and control osmotic pressure (the balance between inorganic ions and water) through excretion. As a result, homeostasis, or the consistency of the organism’s internal environment, is promoted.

Every living thing, from the tiniest protist to the greatest mammal, has to get rid of the potentially dangerous by-products of its necessary functions. Elimination is the term used to describe the many systems and procedures by which living organisms dispose of or throw away waste products, harmful chemicals, and dead parts of the organism. The size and complexity of the organism influence the nature of the process and the specific structures developed for waste disposal.

Types Of Excretory Waste

• Metabolic wastes, such as oxygen in plants and perspiration in humans, are expelled in solid, liquid, and gas forms
• Non-metabolic wastes, such as urine and excreta, are substances in a living organism’s body that are no longer required or valuable to the body

Excretion In Humans

The urinary system of the human body is also known as the human excretory system. The kidneys, ureters, bladder, and urethra are all part of this system. The kidneys are the system’s major functioning unit. The nephron, which is a component of the kidney, assists in filtering the blood and collecting and storing waste in the kidney. In both kidneys, waste from the blood is deposited in the form of urine. Urine flows through the ureters and into the bladder after leaving the kidneys. The bladder can keep urine for a short time, but it cannot store it indefinitely. The bladder pressurises the urine to force it through the urethra and out of our bodies as urine. 

Functions of Kidney

• Toxic chemicals such as urea, uric acid, and ammonia are excreted in our sweat or urine as a result of metabolic activity
• Maintains our body’s homeostatic conditions, such as body temperature and extracellular fluid pH balance
• It also regulates the volume of extracellular fluid and aids in the ionic balance of the fluid
• It removes drugs from the body
• It releases hormones that regulate blood pressure in the body
• It controls the production of red blood cells in the body
• It balances the minerals and chemicals of the body

Disorder of the Excretory System

There are many disorder of excretory system like:

• Kidney Failure

It is one of the most basic problems amongst urinary system diseases and disorders. It mainly occurs when the kidney fails to filter urine by glomerular filtration. 

• Uraemia

This disease is mainly caused when the rate of urea increases in our blood level. This happens when the kidney is not capable of filtering waste.

• Kidney Stone

It is mainly caused due to the deposition of minerals and acid salts within the kidney .Drinking a lot of water regularly and taking some prescribed drug  can cure these diseases.

Excretion in Animals

Diffusion is the process by which excretion takes place in animals with a single layer of cells. Sponge creatures, for example, excrete through specialised cells despite being multicellular animals with a single layer of cells. Gaseous wastes are diffused into the water. It occurs at the site of the organism’s removal of its external environment. Excretion takes place through an extremely intricate excretory system in increasingly evolved creatures. In vertebrates, for example, wastes are excreted by an excretory organ such as the kidney and its associated urinary ducts. 

An elephant, for example, chews his food and then swallows it down his stomach. This is referred to as ingestion. Food is broken down into simpler and soluble compounds in the stomach. This is the process of digestion. The soluble portions are absorbed by the body through the assimilation process. After absorption, enzymes operate on the product, which then undergoes a chemical reaction through metabolism. This results in the production of carbon dioxide, which is exhaled into the atmosphere via the lungs in the respiratory system, the use of oxygen produced, and the excretion of nitrogenous wastes such as uric acid, ammonia, and other nitrogenous wastes through the excretory system and its organs—kidneys and various urinary ducts.

Excretion in Plants

It’s important to remember that plants are living beings with the ability to excrete. Small plants can use their cells to help them go through the excretory process. Wastes are excreted by these plants on the surface of their cells. Large plants are unable to employ these cells since they have limited access to the outside world. As a result, they utilise their cells, just like mammals, to secrete waste from the extracellular spaces, particularly in the leaves. The principal product of plant excretion is oxygen, or O2, which is essential for our survival. Plants exhale oxygen through stomata, which are huge apertures in the leaves. This is also a good summary of the photosynthesis process in plants. These stomata take in the carbon dioxide we exhale and expel the oxygen we take in. The key difference between plant and animal excretion through extracellular spaces is that, unlike animals, the principal byproduct of the plant excretory system is a gaseous form.   

Conclusion

Excretion is the process by which an organism’s metabolic waste is removed. The lungs, kidneys, and skin in vertebrates are principally responsible for this. This differs from secretion, in which the chemical may perform specialised functions after exiting the cell. In all kinds of life, excretion is a necessary activity.

Excretion is a generic phrase that refers to the separation and discharge of waste materials or hazardous compounds from a plant’s or animal’s cells and tissues. Secretion is the separation, elaboration, and removal of specific products resulting from cellular processes in multicellular organisms. Metabolic wastes, such as oxygen in plants and perspiration in humans, are expelled in solid, liquid, and gas forms. Non-metabolic wastes, such as urine and excreta, are substances in a living organism’s body that are no longer required or valuable to the body.