Physiology

Physiology is the branch of science that studies how living things function. It explains how organs, tissues, and cells work together to support life. Physiology helps describe how bodies grow, move, use energy, and respond to their environments. All living things, including plants, animals, and humans, have physiological processes that keep them alive.

Physiology is closely connected to anatomy, which describes the structure of body parts. Anatomy shows what organs look like and where they are located, while physiology explains what these organs do. For example, anatomy describes the shape of the heart, and physiology explains how the heart pumps blood. This relationship helps scientists understand how body structures and functions depend on one another.

Many physiological processes happen constantly. The respiratory system allows living things to take in gases such as oxygen and release carbon dioxide. The circulatory system moves blood, carrying nutrients and oxygen to cells. The digestive system breaks down food into smaller substances the body can use. The nervous system sends signals through the body to coordinate actions, such as moving muscles or reacting to sounds. These systems work together to maintain balance inside the body.

Plants also have physiological processes. They absorb water and nutrients from the soil and transport them through their stems and leaves. Plants use sunlight, carbon dioxide, and water to produce food through photosynthesis. They also release oxygen into the air, which supports other forms of life. Studying plant physiology helps explain how plants grow and respond to changes such as light or moisture.

Physiology can be influenced by many factors, including age, activity level, and the environment. For example, a person’s breathing and heart rate may increase during exercise because the body needs more oxygen and energy. In colder environments, organisms may use energy differently to stay warm. By observing these changes, scientists learn how organisms adapt to different conditions.

Researchers and health professionals use physiology to understand how the body works in both healthy and unhealthy states. This knowledge helps them describe illnesses, study body responses, and understand how treatments or medicines affect various systems. Physiology continues to support science, medicine, and environmental studies by explaining how living things function at many levels—from entire organs to tiny cells.