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Anatomy & Physiology

Human beings have long been curious about the way that things work, and that curiosity includes wondering about how we ourselves work. The fields of anatomy and physiology involve studying the structures of bodies and the way that those structures and bodies function.

Anatomy & Physiology Encyclopedia Articles

Featured Articles

Human body
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 in many different articles. For detailed discussions of specific tissues, organs, and systems, see...
Encyclopedia / Anatomy & Physiology
human body; human anatomy
Anatomy
Anatomy, a field in the biological sciences concerned with the identification and description of the body structures of living things. Gross anatomy involves the study of major body structures by dissection and observation and in its narrowest sense is concerned only with the human body. “Gross...
Encyclopedia / Anatomy & Physiology
Superficial arteries and veins of the face and scalp.
Comparative anatomy
Comparative anatomy, the comparative study of the body structures of different species of animals in order to understand the adaptive changes they have undergone in the course of evolution from common ancestors. Modern comparative anatomy dates from the work of French naturalist Pierre Belon, who...
Encyclopedia / Anatomy & Physiology
skeletons of humans and gorillas compared
Cell cycle
Cell cycle, the ordered sequence of events that occur in a cell in preparation for cell division. The cell cycle is a four-stage process in which the cell increases in size (gap 1, or G1, stage), copies its DNA (synthesis, or S, stage), prepares to divide (gap 2, or G2, stage), and divides...
Encyclopedia / Anatomy & Physiology
Physiology
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...
Encyclopedia / Anatomy & Physiology
adenosine triphosphate; physiology
Blood
Blood, fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products. Technically, blood is a transport liquid pumped by the heart (or an equivalent structure) to all parts of the body, after which it is returned to the heart to repeat the process....
Encyclopedia / Anatomy & Physiology
Blood is made up of multiple components, including red blood cells, white blood cells, platelets, and plasma.
Brain
Brain, the mass of nerve tissue in the anterior end of an organism. The brain integrates sensory information and directs motor responses; in higher vertebrates it is also the centre of learning. The human brain weighs approximately 1.4 kg (3 pounds) and is made up of billions of cells called...
Encyclopedia / Anatomy & Physiology
right cerebral hemisphere of the human brain
Mitochondrion
Mitochondrion, membrane-bound organelle found in the cytoplasm of almost all eukaryotic cells (cells with clearly defined nuclei), the primary function of which is to generate large quantities of energy in the form of adenosine triphosphate (ATP). Mitochondria are typically round to oval in shape...
Encyclopedia / Anatomy & Physiology
mitochondria
Meiosis
Meiosis, division of a germ cell involving two fissions of the nucleus and giving rise to four gametes, or sex cells, each possessing half the number of chromosomes of the original cell. A brief treatment of meiosis follows. For further discussion, see cell: Cell division and growth. The process of...
Encyclopedia / Anatomy & Physiology
meiosis
Human skeleton
Human skeleton, the internal skeleton that serves as a framework for the body. This framework consists of many individual bones and cartilages. There also are bands of fibrous connective tissue—the ligaments and the tendons—in intimate relationship with the parts of the skeleton. This article is...
Encyclopedia / Anatomy & Physiology
skeletal system, human
Immune system
Immune system, the complex group of defense responses found in humans and other advanced vertebrates that helps repel disease-causing organisms (pathogens). Immunity from disease is actually conferred by two cooperative defense systems, called nonspecific, innate immunity and specific, acquired...
Encyclopedia / Anatomy & Physiology
Stimulation of immune response by activated helper T cellsActivated by complex interaction with molecules on the surface of a macrophage or some other antigen-presenting cell, a helper T cell proliferates into two general subtypes, TH1 and TH2. These in turn stimulate the complex pathways of the cell-mediated immune response and the humoral immune response, respectively.
Human eye
Human eye, in humans, specialized sense organ capable of receiving visual images, which are then carried to the brain. The eye is protected from mechanical injury by being enclosed in a socket, or orbit, which is made up of portions of several of the bones of the skull to form a four-sided pyramid,...
Encyclopedia / Anatomy & Physiology
A horizontal cross section of the human eye, showing the major parts of the eye, including the protective covering of the cornea over the front of the eye.

Anatomy & Physiology Encyclopedia Articles

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