Excretion and Secretion: Introduction
In nature, "secretion" and "excretion" are similar since both entail the passage or movement of elements. These words and bodily processes are required to manage and sustain equilibrium. Both systems transport and remove waste from the body. Excretion in biology is defined as the elimination of nitrogenous waste material from the body. Secretion is the process of producing and releasing chemicals from a cell, gland, or organ. Human secretory products include substances such as hormones, enzymes, and saliva.
What is Excretion?
Excretion is the process by which all metabolic wastes are eliminated from the body. Excretion in humans occurs in a series of processes that involve various body parts and internal organs. Diffusion is the most common excretory process in lower organisms.
The breakdown of nitrogenous molecules such as proteins and nucleic acids results in the creation of NH3, uric acid, urea, and other chemicals.
The buildup of these excretory chemicals disrupts pH and homeostasis. This may result in slowed metabolism and cell poisoning, ultimately leading to the organism's death. As a result, these metabolic wastes must be expelled from the body through a process known as excretion.
CO2 and H2O are excreted through the respiratory system, and then skin excretion takes place. The role of skin in excretion is through the production of sweat by sweat glands. Sweating eliminates excess water and salts, as well as a small amount of urea, a byproduct of protein catabolism.
The excretory organ, the kidney, is a significant excretory organ. Humans have kidneys that are shaped like beans. They are located in the posterior abdominal area on each side of the spinal column. The right kidney is somewhat lower than the left.
Animals are classified into three Broad Classes based on Excretory Products:
Ammonotelic Animals: Ammonotelic animals are species whose primary excreta is ammonia, and ammonotelism is the process of eliminating ammonia. Ammonia is very poisonous and cannot be kept in the body for an extended period of time. Since it is easily soluble in water, it is the primary excreta of aquatic crustaceans, annelids, molluscs, echinoderms, bony fish, and amphibian larvae.
Uricotelic Animals: These are organisms whose primary excreta is uric acid, and uricotelism is the process by which uric acid is eliminated. Uric acid is the least poisonous and is soluble in water. As a result, it is the principal excreta in species that preserve water. Insects, land snails, reptiles, and birds are a few examples.
Ureotelic Animals: Ureotelic animals are those whose primary excreta is urea, and ureotelism is the act of eliminating urea. Urea is more poisonous than uric acid but less hazardous than ammonia. Ammonia combines with CO2 in the liver to create urea during the ornithine cycle. All cartilaginous fishes, mature amphibians, and mammals are ureotelic.
What is Secretion?
Secretion refers to the production and release of a functional material by a gland or cell. Body tissues release a variety of chemicals that provide lubrication and moisture, in addition to enzymes and hormones that enable and regulate complicated biochemical processes.
Skin secretions are produced by glands located in the dermal layer of the epidermis. Sweat is released by the sebaceous gland as physiological assistance to body temperature control. The skin lubricant sebum is produced by sebaceous glands.
Sebum is secreted onto the hair roots to keep them from breaking. It is largely made up of lipids. After spreading along and up the hair shaft, sebum is disseminated throughout the skin surface, lubricating and waterproofing the stratum corneum, the skin's outer layer.
Difference Between Secretion and Excretion
Conclusion
The terms "secretion" and "excretion" are comparable in nature since both entail the passage or movement of materials.
"Excretion" refers to the removal of material from a living entity, whereas "secretion" refers to the passage of material from one location to another.
Excreta are largely bodily wastes, whereas secretions are vital elements that our systems may convert and utilise.
FAQs on Difference Between Excretion and Secretion
1. What other organs are involved in excretion?
Apart from the kidneys, the lungs, liver, and skin contribute to excretory waste removal.
Lungs: In a normal state, the lungs excrete a considerable amount of CO2 (200 mL/min) as well as a significant amount of water. Water loss via the lungs is minimal in hot, humid regions and substantial in cold, dry areas.
Liver: The liver is our body's biggest gland. It is the primary location for the removal of cholesterol, bile pigments (bilirubin and biliverdin), degraded steroid hormones, some vitamins, and many medicines. These chemicals are secreted by the liver in the form of bile. Bile, in turn, transports these elements to the gut, where they are eventually removed with the faeces.
2. Where is urine produced?
Urine is formed by urea, water, and other waste substances travelling through the nephrons and through the renal tubules of the kidney. There are two ureters. These slender tubes transport urine from the kidneys to the bladder.
The kidney's nephrons filter blood and produce urine through a process of reabsorption, filtration, and secretion. Urine is composed of approximately 95% water and 5% waste materials. Urea, creatinine, ammonia, and uric acid are examples of nitrogenous wastes discharged in urine.
3. What are plant excretory products?
Unlike animals, plants do not have specialised excretory organs. Excess carbon dioxide and oxygen are excreted from the plant through the stomata in the leaves. The principal excretory products in plants are carbon dioxide, excess water produced during respiration, and nitrogenous chemicals created during protein metabolism. Plants can get rid of excess water by transpiration and guttation. It has been shown that the leaf acts as an "excretophore." In addition to being a primary organ of photosynthesis, leaves are also used as a method of excreting toxic waste via diffusion.
