Structure and Functions (Magill’s Medical Guide, Sixth Edition)
The body’s parts can be categorized either regionally or functionally. Regionally, the body consists of a trunk to which are attached two upper extremities, two lower extremities, and a head, attached by means of a neck. Functionally, the body consists of a digestive system, a circulatory system, an excretory system, a respiratory system, a reproductive system, a nervous system, an endocrine system, an integument (skin), a skeleton, and a series of muscles.
Regionally, the body consists of a central portion called the trunk, to which other parts are attached. The trunk itself may be divided into an upper portion called the chest (or thorax), containing ribs, and a lower, rib-free portion called the abdomen. Internally, the thorax and abdomen are separated by a muscular sheet called the diaphragm. Attached to the trunk are two upper extremities, two lower extremities, and a head. The upper extremities include the arms, forearms, and hands; the lower extremities include the thighs, lower legs, and feet. The head includes the brain and the major sense organs such as the eyes and ears; the neck is the narrower, flexible part that connects the head to the trunk. The ventral (front) surface of the abdomen is often divided around the umbilicus into upper-left, upper-right, lower-left, and lower-right quadrants.
Functionally, the body consists of a number of organ systems: a digestive system, a circulatory system, an...
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Disorders and Diseases (Magill’s Medical Guide, Sixth Edition)
Diseases or disorders that affect the entire body are called systemic or multisystem diseases. For example, fevers or febrile diseases raise the body’s temperature. Many fevers are caused by infectious diseases such as influenza (actually a series of different viral infections). Influenzas cause fever, sore throat, muscle aches, coughs, headache, fatigue, and a general feeling of malaise.
Edema, or tissue swelling, is marked by an increase in the amount of extracellular fluid in several parts of the body at once. In the case of pulmonary edema, the fluid stains pink and fills the usually empty lung spaces (alveoli).
Most cancers are recognized by abnormalities of the cells in which they occur. The most dangerous cancers are marked by large tumors with ill-defined, irregular margins. If the cancer tumor is well defined, is small, and has a smooth, circular margin, then it is much less of a threat. Cancers are especially dangerous when they undergo metastasis, a process by which they produce wandering cells that spread throughout the body.
Juvenile diabetes mellitus (also called diabetes mellitus, type 1, and insulin-dependent diabetes mellitus, or IDDM), like most endocrine disorders, has systemic consequences throughout the body, including damage to nearly all the blood vessels. The primary defect in this disorder is a lack of insulin, which impairs the body’s ability to use glucose. Another endocrine...
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Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
The Latin names that are used today for most body parts are derived in large measure from the writings of Galen, or Caius Galenus, the physician to the Roman army in the second century. The study of anatomy was furthered in the Renaissance by artists such as Leonardo da Vinci (1452-1519) and Michelangelo (1475-1564), both of whom dissected human corpses illegally in order to gain further knowledge of the anatomical structures visible on the body’s surface. Such studies were followed by the well-illustrated anatomical texts of Andreas Vesalius (1514-1564), who corrected many of Galen’s errors regarding the structure of the human body.
A medical understanding of the circulatory system began with the studies of the Renaissance physician William Harvey (1578-1657), who examined the veins in the arms of many patients. It was Harvey who first described the presence of valves in the veins and who proved that the blood circulates outward from the heart, throughout the body, and then back again to the heart.
Microscopes were first developed around 1700 by Antoni van Leeuwenhoek (1632-1723) and others. Electron microscopes first became commercially available in the 1950’s. Microscopy using instruments of these two types was widely used for distinguishing between healthy and diseased tissue, in tissue taken either from bodies at autopsy or from biopsies of living patients. Modern diagnostic radiology began with...
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For Further Information: (Magill’s Medical Guide, Sixth Edition)
Abrahams, Peter H., Sandy C. Marks, Jr., and Ralph Hutchings. McMinn’s Color Atlas of Human Anatomy. 6th ed. St. Louis, Mo.: Mosby/Elsevier, 2008. A useful set of color illustrations covering all parts of the body.
Agur, Anne M. R., and Arthur F. Dalley. Grant’s Atlas of Anatomy. 12th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2009. Offers many excellent, detailed illustrations of the human body.
Crouch, James E. Functional Human Anatomy. 4th ed. Philadelphia: Lea & Febiger, 1985. An easy-to-read book that offers helpful explanations. A good reference source for the beginning anatomy student or nonscientist.
Marieb, Elaine N. Essentials of Human Anatomy and Physiology. 9th ed. San Francisco: Pearson/Benjamin Cummings, 2009. This introductory anatomy and physiology textbook, easily accessible to those with little science background, is richly illustrated with diagrams and photographs, which help to illuminate body systems and processes.
Moore, Keith L., and Anne M. R. Agur. Essential Clinical Anatomy. 4th ed. Philadelphia: Lippincott Williams & Wilkins, 2011. A basic text that examines the importance and function of anatomy.
Netter, Frank H. The CIBA Collection of Medical Illustrations. 8 vols. West Caldwell, N.J.: CIBA Pharmaceutical, 1995. A large-format set of excellent medical illustrations...
(The entire section is 291 words.)
Anatomy (Encyclopedia of Science)
Anatomy is a branch of biology that deals with the structure of plants and animals. Comparative anatomy is a related field in which the structures of different animals are studied and compared. There are three main areas of anatomy: gross anatomy deals with organs and organ groupings called systems that are visible to the naked eye; cytology is the study of cell structure; and histology examines the structure of tissues. Microscopes are used in both cytology and histology to study cell and tissue structures.
History of anatomy
Attempts to understand the structure of living things go as far back as Aristotle (38422 B.C.), the famous Greek philosopher and biologist. His dissection (cutting into pieces to examine the parts) and study of animals and plants led to his formation of a classification system that was used by scientists for almost 2,000 years.
Some of the first human dissections were carried out by Greek anatomists and physicians Herophilus (late fourth century B.C.) and his younger follower Erasistratus. Herophilus made many anatomical studies of the brain. He distinguished the cerebrum (larger portion) from the cerebellum (smaller portion), suggested that the brain was the seat of intelligence, and identified and named several structures of the brain, some of which still carry the names he gave them. He also discovered that nerves...
(The entire section is 1282 words.)