organele

Organele are specialized structures within an organism that perform distinct physiological functions necessary for growth, metabolism, and homeostasis. In humans and other vertebrates, organs are grouped into organ systems that coordinate the body's activities.

Most organs are composed of multiple tissue types—epithelial, connective, muscular, and nervous tissues—arranged to support a specific function. Some organs also contain specialized substructures, such as valves, ducts, or glands, that facilitate their role.

Examples of essential human organs and their primary functions include the heart, which pumps blood; the lungs, enabling gas exchange; the liver, which metabolizes nutrients and detoxifies substances and produces bile; the kidneys, which filter waste and regulate fluid balance; the brain and spinal cord, which coordinate thought, sensation, and movement; the stomach and intestines, which digest and absorb nutrients; and the skin, which protects the body and regulates temperature.

Organ systems reflect the integrated nature of organele: the circulatory, respiratory, digestive, nervous, endocrine, urinary, reproductive, muscular and skeletal, and integumentary systems work together to maintain homeostasis.

Developmentally, organs form through organogenesis during embryonic development from the three germ layers, and their structure adapts to life stage and environmental conditions. Across species, organ form and function vary with ecological needs and evolutionary history.

Clinical relevance: organ health is critical; organ damage or failure can be life-threatening. Medical advances include organ transplantation and regenerative therapies, alongside prevention and treatment strategies to preserve organ function.