Ekskreetio

Ekskreetio, also known as excretion, is the biological process by which an organism eliminates metabolic waste products and other non-essential substances from its body. These waste products are typically the result of cellular metabolism, which breaks down nutrients for energy and other functions. Without effective excretion, these waste substances can accumulate to toxic levels, harming the organism.

Different organisms have evolved various excretory systems to manage waste removal. In animals, common waste products include urea (from protein breakdown), carbon dioxide (from respiration), and excess salts and water. The primary organs involved in excretion in mammals are the kidneys, which filter blood to produce urine. The lungs excrete carbon dioxide, and the skin excretes some waste products through sweat. Invertebrates often possess simpler structures like nephridia or Malpighian tubules to perform similar functions.

Plants also produce metabolic wastes, though their systems differ. For instance, they can store some waste products in their leaves, which are then shed. Excess carbon dioxide is released through stomata, and oxygen, a byproduct of photosynthesis, is also excreted. The efficient removal of waste is crucial for maintaining homeostasis, the stable internal environment necessary for life.