Physiology | Definition & Bodily Function | Britannica
2024年11月15日 · physiology, study of the functioning of living organisms, animal or plant, and of the functioning of their constituent tissues or cells. The word physiology was first used by the Greeks around 600 bce to describe a philosophical inquiry into the nature of things. The use of the term with specific reference to vital activities of healthy humans ...
Human body | Organs, Systems, Structure, Diagram, & Facts
2024年11月24日 · The human body is the physical substance of the human organism. Characteristic of the vertebrate form, the human body has an internal skeleton with a backbone, and, as with the mammalian form, it has hair and mammary glands. Learn more about the composition, form, and physical adaptations of the human body.
Reflex | Physiology, Definition, Types & Examples | Britannica
human nervous system: Reflex actions In its simplest form, a reflex is viewed as a function of an idealized mechanism called the reflex arc . The primary components of the reflex arc are the sensory-nerve cells (or receptor s) that receive stimulation, in turn connecting to other nerve cells that activate muscle cells (or effectors), which ...
Human ear - Hearing, Anatomy, Physiology | Britannica
2024年11月21日 · Human ear - Hearing, Anatomy, Physiology: Hearing is the process by which the ear transforms sound vibrations in the external environment into nerve impulses that are conveyed to the brain, where they are interpreted as sounds.
Renal system | Definition, Function, Diagram, & Facts | Britannica
In many respects the human excretory, or urinary, system resembles those of other mammalian species, but it has its own unique structural and functional characteristics. The terms excretory and urinary emphasize the elimination function of the system.
Human behavior | Definition, Theories, Characteristics, Examples, …
2024年10月3日 · Human behavior, the potential and expressed capacity for physical, mental, and social activity throughout human life. Humans, like other animal species, have a typical life course that consists of successive phases of growth, each characterized by a distinct set of physical, physiological, and behavioral features.
Homeostasis | Definition, Function, Examples, & Facts | Britannica
2024年10月22日 · The “stability” that the organism reaches is rarely around an exact point (such as the idealized human body temperature of 37 °C [98.6 °F]). Stability takes place as part of a dynamic equilibrium , which can be thought of as a cloud of values within a tight range in which continuous change occurs.
Human cardiovascular system | Description, Anatomy, & Function
human cardiovascular system, organ system that conveys blood through vessels to and from all parts of the body, carrying nutrients and oxygen to tissues and removing carbon dioxide and other wastes. It is a closed tubular system in which the blood is propelled by a muscular heart.
Anatomy & Physiology Portal | Britannica
Human body, the physical substance of the human organism, composed of living cells and extracellular materials and organized into tissues, organs, and systems. Human anatomy and physiology are treated...
Human digestive system | Description, Parts, & Functions | Britannica
2024年10月25日 · The human digestive system is the series of structures and organs through which food and liquids pass during their processing into forms that can be absorbed into the bloodstream.