organen

Organen, the Dutch term for organs, are differentiated parts of an organism that are composed of two or more tissues and perform one or more specific biological functions. In multicellular animals, organs are organized into organ systems, such as the circulatory system or the digestive system. Common human organs include the heart, lungs, liver, kidneys, brain, and stomach.

Organs are structured to carry out their functions efficiently. They typically contain parenchymal tissue, which carries out the organ's primary task, and supporting tissues such as connective tissue, muscle, and blood vessels that supply oxygen and nutrients and remove waste. The arrangement of tissues varies by organ and species.

Organs develop through embryonic growth and maturation, and their size, shape, and function may vary between individuals and species. Some organs are paired (kidneys, lungs), while others are singular (the brain, liver).

Understanding organ function is central to medicine and biology. The health of organs can be assessed by imaging, histology, and functional tests. Diseases can impair the structure or function of organs, and in some cases organs may be replaced or supported through procedures such as transplantation or assistive devices.

Organ is from Latin organum, meaning a tool or instrument. The concept of organs also applies to plants, where organs such as leaves, roots, stems, and reproductive structures perform specific functions necessary for growth and reproduction.