large system
81endocrine system, human — ▪ anatomy Introduction group of ductless glands (gland) that regulate body processes by secreting chemical substances called hormones (hormone). Hormones act on nearby tissues or are carried in the bloodstream to act on specific target organs… …
82nervous system, human — ▪ anatomy Introduction system that conducts stimuli from sensory receptors to the brain and spinal cord and that conducts impulses back to other parts of the body. As with other higher vertebrates, the human nervous system has two main… …
83nervous system — Anat., Zool. 1. the system of nerves and nerve centers in an animal or human, including the brain, spinal cord, nerves, and ganglia. 2. a particular part of this system. Cf. autonomic nervous system, central nervous system, peripheral nervous… …
84digestive system, human — Introduction the system used in the human body for the process of digestion. The human digestive system consists primarily of the digestive tract (alimentary canal), or the series of structures and organs through which food and liquids pass… …
85Solar System — This article is about the Sun and its planetary system. For other systems, see planetary system and star system. For a list of physical and orbital statistics for the Solar System s largest bodies, see List of gravitationally rounded objects of… …
86Formation and evolution of the Solar System — Artist s conception of a protoplanetary disk The formation and evolution of the Solar System is estimated to have begun 4.568 billion years ago with the gravitational collapse of a small part of a giant molecular cloud …
87immune system — Anat. a diffuse, complex network of interacting cells, cell products, and cell forming tissues that protects the body from pathogens and other foreign substances, destroys infected and malignant cells, and removes cellular debris: the system… …
88digestive system disease — Introduction any of the diseases that affect the human digestive tract. Such disorders may affect the esophagus, stomach, small intestine, large intestine (colon), pancreas, liver, or biliary tract. A prevalent disorder of the digestive… …
89political system — Introduction the set of formal legal institutions that constitute a “government” or a “ state.” This is the definition adopted by many studies of the legal or constitutional arrangements of advanced political orders. More broadly defined,… …
90Health care system — A health care system is the organization of people, institutions, and resources to deliver health care services to meet the health needs of target populations. There is a wide variety of health care systems around the world, with as many… …
