The Skin as an Excretory Organ Parts of the skin (epidermis, dermis, sweat glands, sweat ducts, pores, hair). Functions of the skin. Waste products excreted through the skin (sweat: water, salts, urea). Temperature regulation.

Excretion is the process of removal of toxic wastes from the body of an organism. The major wastes produced by us are: Carbon dioxide and Urea. Carbon dioxide is produced by the process of respiration and urea is produced by the decomposition of unused proteins in the liver. There are different organs which removes waste from the body. These are lungs and kidneys. Our lungs excrete carbon dioxide and kidneys urea. Urinary system The kidneys are large, bean-shaped organs which are present on each side of the vertebral column in the abdominal cavity. Humans have two kidneys and each kidney is supplied with blood from the renal artery. The kidneys remove from the blood the nitrogenous wastes such as urea, as well as salts and excess water, and excrete them in the form of urine. This is done with the help of millions of nephrons present in the kidney. The filtrated blood is carried away from the kidneys by the renal vein (or kidney vein). The urine from the kidney is collected by the ureter (or excretory tubes), one from each kidney, and is passed to the urinary bladder. The urinary bladder collects and stores the urine until urination. The urine collected in the bladder is passed into the external environment from the body through an opening called the urethra. Kidneys The kidney's primary function is the elimination of waste from the bloodstream by production of urine. They perform several homeostatic functions such as:- Maintain volume of extracellular fluid Maintain ionic balance in extracellular fluid Maintain pH and osmotic concentration of the extracellular fluid. Excrete toxic metabolic by-products such as urea, ammonia, and uric acid. The way the kidneys do this is with nephrons. There are over 1 million nephrons in each kidney; these nephrons act as filters inside the kidneys. The kidneys filter needed materials and waste, the needed materials go back into the bloodstream, and unneeded materials becomes urine and is gotten rid of. Ureter The ureters are muscular ducts that propel urine from the kidneys to the urinary bladder. In the human adult, the ureters are usually 25–30 cm (10–12 in) long. In humans, the ureters arise from the renal pelvis on the medial aspect of each kidney before descending towards the bladder. Urinary bladder The urinary bladder is the organ that collects waste excreted by the kidneys prior to disposal by urination. It is a hollow muscular, and distensible (or elastic) organ, and sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra. Urethra is a tube which connects the urinary bladder to the outside of the body. In humans, the urethra has an excretory function in both genders to pass. Respiratory system One of the main functions of the lungs is to diffuse gaseous wastes, such as carbon dioxide, from the bloodstream as a normal part of respiration. Biliary system The liver detoxifies and breaks down chemicals, poisons and other toxins that enter the body. For example, the liver transforms ammonia (which is poisonous) into urea in fish, amphibians and mammals, and into uric acid in birds and reptiles. Urea is filtered by the kidney into urine or through the gills in fish and tadpoles. Uric acid is paste-like and expelled as a semi-solid waste (the "white" in bird excrements). The liver also produces bile, and the body uses bile to break down fats into usable fats and unusable waste. Skin Sweat glands in the skin secrete a fluid waste called sweat or perspiration; however, its primary functions are temperature control and pheromone release. Therefore, its role as a part of the excretory system is minimal. Sweating also maintains the level of salt in the body.

In this part of our Biology series on "Excretory Products and Their Elimination," we dive into the world of excretory system diseases. Join me and as we explore various disorders and their impact on the excretory system. Gain a deeper understanding of the causes, symptoms, and treatments of these diseases, and learn how they affect the overall functioning of our bodies.

A clear, engaging PowerPoint Outline on Force and Electrical Energy – Sources of Electricity

Most electricity is generated by rotating turbines that are connected to generators that produce an electric current. This video explains how that electricity is generated and what kinds of fuels generate electricity in the United States and around the world.

Learners to use electrical apparatus to set up simple electrical circuits in series and in parallel

In this activity, learners use simple electrical apparatus—batteries, wires, bulbs, and a switch—to construct series and parallel circuits. In the series circuit, the components are connected one after another in a single path, so if one bulb goes off, the entire circuit stops working. In the parallel circuit, the components are connected side by side, giving electricity more than one path to flow; therefore, if one bulb goes off, the others continue to work. Through this practical, learners observe the differences in brightness of bulbs, reliability of each type of circuit, and understand how electricity flows depending on the circuit arrangement.

In this lesson, we will be learning how to classify matter according to its ability to conduct electric or thermal energy.

These notes introduce learners to the concepts of conductors and non-conductors (insulators) of electricity. They explain that conductors are materials—mainly metals such as copper, aluminium, and iron—that allow electricity to flow through them easily, while non-conductors like rubber, plastic, and wood prevent the flow of electricity.

Electricity is an essential part of modern life. It powers our homes, our schools, our workplaces, and our devices. But where does electricity come from, and how do we use it? Sources of Electricity: There are several sources of electricity. A common source is through the use of power stations, which burn fossil fuels like coal, oil, and natural gas to generate electricity. These power stations are often located near large cities and towns, and the electricity they produce is transported through power lines to homes and businesses. Renewable sources of electricity are becoming increasingly popular as concerns about the environment and climate change grow. Hydroelectric power plants use the energy of falling water to generate electricity. Solar panels use the energy of the sun to generate electricity, and wind turbines use the energy of the wind. These renewable sources of electricity are clean and sustainable, and they do not produce greenhouse gas emissions. Batteries are another common source of electricity. They are used to power small devices like toys, remote controls, and flashlights. They work by converting chemical energy into electrical energy. Uses of Electricity: Electricity has many uses in our daily lives. We use it to power lights, appliances, and devices like smartphones and computers. It powers the heating and cooling systems in our homes and buildings, and it is used to power public transportation systems like trains and trams. Electricity is also becoming an increasingly popular source of power for cars and other vehicles. These Electric vehicles (EVs) are powered by electricity stored in rechargeable batteries, rather than gasoline or diesel fuel. EVs are becoming more common on roads around the world, with many major automakers producing electric cars, trucks, and buses. Electricity is also used in industry, where it powers machines and equipment used in manufacturing and production. It is used to power medical equipment in hospitals and clinics, and it is used to power communication systems like radios, televisions, and the internet. Using Electricity Wisely and Safely: While electricity is incredibly useful, it is important to use it wisely and safely. One way to do this is to reduce our energy consumption. This can be done by turning off lights and appliances when they are not in use, and by choosing energy-efficient appliances. Another way to use electricity wisely is to generate our own electricity from renewable sources like solar and wind power. By installing solar panels on our homes, we can reduce our need to get electricity from power stations, which can help reduce our carbon footprint and lower our energy bills. It's also important to use electricity safely, especially when it comes to electrical installation and repairs. Only qualified electricians should be hired to install or repair electrical appliances or wiring. Always avoid touching electrical outlets or wires, and never use electrical appliances near water. It's also important to keep electrical cords in good condition. Electricity is a crucial aspect of modern life, and it powers almost everything we use and rely on daily. As we continue to innovate and find new ways to use and generate electricity sustainably, we'll ensure a bright future for generations to come.