Anatomy definition: 1. The scientific study of the body and how its parts are arranged: 2. The structure of an animal. 3D modeled by physicians and anatomy experts. Using the International Anatomical Terminology. +6000 anatomical structures. Add, Delete and Combine anatomical structures.

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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, seehuman blood; cardiovascular system; digestive system, human; endocrine system, human; renal system; skin; human muscle system; nervous system; reproductive system, human; respiration, human; sensory reception, human; skeletal system, human. For a description of how the body develops, from conception through old age, seeaging; growth; prenatal development; human development.

For detailed coverage of the body’s biochemical constituents, seeprotein; carbohydrate; lipid; nucleic acid; vitamin; and hormone. For information on the structure and function of the cells that constitute the body, seecell.

Many entries describe the body’s major structures. For example, seeabdominal cavity; adrenal gland; aorta; bone; brain; ear; eye; heart; kidney; large intestine; lung; nose; ovary; pancreas; pituitary gland; small intestine; spinal cord; spleen; stomach; testis; thymus; thyroid gland; tooth; uterus; vertebral column.

Humans are, of course, animals—more particularly, members of the order Primates in the subphylum Vertebrata of the phylum Chordata. Like all chordates, the human animal has a bilaterally symmetrical body that is characterized at some point during its development by a dorsal supporting rod (the notochord), gill slits in the region of the pharynx, and a hollow dorsal nerve cord. Of these features, the first two are present only during the embryonic stage in the human; the notochord is replaced by the vertebral column, and the pharyngeal gill slits are lost completely. The dorsal nerve cord is the spinal cord in humans; it remains throughout life.

Characteristic of the vertebrate form, the human body has an internal skeleton that includes a backbone of vertebrae. Typical of mammalian structure, the human body shows such characteristics as hair, mammary glands, and highly developed sense organs.

Beyond these similarities, however, lie some profound differences. Among the mammals, only humans have a predominantly two-legged (bipedal) posture, a fact that has greatly modified the general mammalian body plan. (Even the kangaroo, which hops on two legs when moving rapidly, walks on four legs and uses its tail as a “third leg” when standing.) Moreover, the human brain, particularly the neocortex, is far and away the most highly developed in the animal kingdom. As intelligent as are many other mammals—such as chimpanzees and dolphins—none have achieved the intellectual status of the human species.

Chemical composition of the body

Chemically, the human body consists mainly of water and of organic compounds—i.e., lipids, proteins, carbohydrates, and nucleic acids. Water is found in the extracellular fluids of the body (the blood plasma, the lymph, and the interstitial fluid) and within the cells themselves. It serves as a solvent without which the chemistry of life could not take place. The human body is about 60 percent water by weight.

Lipids—chiefly fats, phospholipids, and steroids—are major structural components of the human body. Fats provide an energy reserve for the body, and fat pads also serve as insulation and shock absorbers. Phospholipids and the steroid compoundcholesterol are major components of the membrane that surrounds each cell.

Proteins also serve as a major structural component of the body. Like lipids, proteins are an important constituent of the cell membrane. In addition, such extracellular materials as hair and nails are composed of protein. So also is collagen, the fibrous, elastic material that makes up much of the body’s skin, bones, tendons, and ligaments. Proteins also perform numerous functional roles in the body. Particularly important are cellular proteins called enzymes, which catalyze the chemical reactions necessary for life.

Carbohydrates are present in the human body largely as fuels, either as simple sugars circulating through the bloodstream or as glycogen, a storage compound found in the liver and the muscles. Small amounts of carbohydrates also occur in cell membranes, but, in contrast to plants and many invertebrate animals, humans have little structural carbohydrate in their bodies.

Nucleic acids make up the genetic materials of the body. Deoxyribonucleic acid (DNA) carries the body’s hereditary master code, the instructions according to which each cell operates. It is DNA, passed from parents to offspring, that dictates the inherited characteristics of each individual human. Ribonucleic acid (RNA), of which there are several types, helps carry out the instructions encoded in the DNA.

Along with water and organic compounds, the body’s constituents include various inorganic minerals. Chief among these are calcium, phosphorus, sodium, magnesium, and iron. Calcium and phosphorus, combined as calcium-phosphate crystals, form a large part of the body’s bones. Calcium is also present as ions in the blood and interstitial fluid, as is sodium. Ions of phosphorus, potassium, and magnesium, on the other hand, are abundant within the intercellular fluid. All of these ions play vital roles in the body’s metabolic processes. Iron is present mainly as part of hemoglobin, the oxygen-carrying pigment of the red blood cells. Other mineral constituents of the body, found in minute but necessary concentrations, include cobalt, copper, iodine, manganese, and zinc.

Organization of the body

The cell is the basic living unit of the human body—indeed, of all organisms. The human body consists of trillions of cells, each capable of growth, metabolism, response to stimuli, and, with some exceptions, reproduction. Although there are some 200 different types of cells in the body, these can be grouped into four basic classes. These four basic cell types, together with their extracellular materials, form the fundamental tissues of the human body: (1) epithelial tissues, which cover the body’s surface and line the internal organs, body cavities, and passageways; (2) muscle tissues, which are capable of contraction and form the body’s musculature; (3) nerve tissues, which conduct electrical impulses and make up the nervous system; and (4) connective tissues, which are composed of widely spaced cells and large amounts of intercellular matrix and which bind together various body structures. (Bone and blood are considered specialized connective tissues, in which the intercellular matrix is, respectively, hard and liquid.)

The next level of organization in the body is that of the organ. An organ is a group of tissues that constitutes a distinct structural and functional unit. Thus, the heart is an organ composed of all four tissues, whose function is to pump blood throughout the body. Of course, the heart does not function in isolation; it is part of a system composed of blood and blood vessels as well. The highest level of body organization, then, is that of the organ system.

The body includes nine major organ systems, each composed of various organs and tissues that work together as a functional unit. The chief constituents and prime functions of each system are summarized below. (1) The integumentary system, composed of the skin and associated structures, protects the body from invasion by harmful microorganisms and chemicals; it also prevents water loss from the body. (2) The musculoskeletal system (also referred to separately as the muscle system and the skeletal system), composed of the skeletal muscles and bones (with about 206 of the latter in adults), moves the body and protectively houses its internal organs. (3) The respiratory system, composed of the breathing passages, lungs, and muscles of respiration, obtains from the air the oxygen necessary for cellular metabolism; it also returns to the air the carbon dioxide that forms as a waste product of such metabolism. (4) The circulatory system, composed of the heart, blood, and blood vessels, circulates a transport fluid throughout the body, providing the cells with a steady supply of oxygen and nutrients and carrying away waste products such as carbon dioxide and toxic nitrogen compounds. (5) The digestive system, composed of the mouth, esophagus, stomach, and intestines, breaks down food into usable substances (nutrients), which are then absorbed from the blood or lymph; this system also eliminates the unusable or excess portion of the food as fecal matter. (6) The excretory system, composed of the kidneys, ureters, urinary bladder, and urethra, removes toxic nitrogen compounds and other wastes from the blood. (7) The nervous system, composed of the sensory organs, brain, spinal cord, and nerves, transmits, integrates, and analyzes sensory information and carries impulses to effect the appropriate muscular or glandular responses. (8) The endocrine system, composed of the hormone-secreting glands and tissues, provides a chemical communications network for coordinating various body processes. (9) The reproductive system, composed of the male or female sex organs, enables reproduction and thereby ensures the continuation of the species.

did you know?

• The human femur can support a weight thirty times that of the human body, making it even stronger than steel.
  
• The evolution of the human eyebrows is believed to have prevented the influx of sweat into the eyes.
  
• Chronic stress produces high levels of cortisol, which may cause damage to the hippocampus in the brain, leading to memory loss.
  
• An increase in the volume of background noise has been correlated with the perception of food as less sweet or less salty.
  
• The human nervous system can relay electrochemical messages at a rate of 249 mph (400 km/hr).
  

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a·nat·o·my

(ə-năt′ə-mē)n.pl.a·nat·o·mies

anatomy

(əˈnætəmɪ) n, pl-mies

a•nat•o•my

(əˈnæt ə mi)
n., pl. -mies.

a·nat·o·my

(ə-năt′ə-mē)

Anatomy

anatomy

Noun	1.	anatomy - the branch of morphology that deals with the structure of animals apparatus - (anatomy) a group of body parts that work together to perform a given function; 'the breathing apparatus' vallecula, groove - (anatomy) any furrow or channel on a bodily structure or part partition - (anatomy) a structure that separates areas in an organism septum - (anatomy) a dividing partition between two tissues or cavities fissure - (anatomy) a long narrow slit or groove that divides an organ into lobes sulcus - (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain hilum, hilus - (anatomy) a depression or fissure where vessels or nerves or ducts enter a bodily organ; 'the hilus of the kidney' cingulum - (anatomy) an encircling structure (as the ridge around the base of a tooth) concha - (anatomy) a structure that resembles a shell in shape radicle - (anatomy) a small structure resembling a rootlet (such as a fibril of a nerve) tube-shaped structure, tube - (anatomy) any hollow cylindrical body structure fundus - (anatomy) the base of a hollow organ or that part of the organ farthest from its opening; 'the uterine fundus'; 'the fundus of the stomach' meniscus, semilunar cartilage - (anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint bodily cavity, cavum, cavity - (anatomy) a natural hollow or sinus within the body diaphragm, midriff - (anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration apophysis - (anatomy) a natural outgrowth or projection on an organ or body part such as the process of a vertebra lobe - (anatomy) a somewhat rounded subdivision of a bodily organ or part; 'ear lobe' pouch, pocket - (anatomy) saclike structure in any of various animals (as a marsupial or gopher or pelican) articulatio, joint, articulation - (anatomy) the point of connection between two bones or elements of a skeleton (especially if it allows motion) paries, wall - (anatomy) a layer (a lining or membrane) that encloses a structure; 'stomach walls' cornu - (anatomy) any structure that resembles a horn in shape corona - (anatomy) any structure that resembles a crown in shape ruga - (anatomy) a fold or wrinkle or crease; 'rugae of the stomach' tentorium - (anatomy) a fold of dura mater that covers the cerebellum and supports the occipital lobes of the cerebrum zona, zone - (anatomy) any encircling or beltlike structure applied anatomy, clinical anatomy - the practical application of anatomical knowledge to diagnosis and treatment comparative anatomy - the study of anatomical features of animals of different species developmental anatomy - the branch of anatomy that studies structural changes of an individual from fertilization to maturity functional anatomy, morphophysiology, physiological anatomy - the study of anatomy in its relation to function gross anatomy, macroscopic anatomy - the study of the structure of the body and its parts without the use of a microscope microscopic anatomy - the study of microscopic structures of tissues and organs osteology - the branch of anatomy that studies the bones of the vertebrate skeleton regional anatomy, topographic anatomy, topology - the study of anatomy based on regions or divisions of the body and emphasizing the relations between various structures (muscles and nerves and arteries etc.) in that region morphology - the branch of biology that deals with the structure of animals and plants base - (anatomy) the part of an organ nearest its point of attachment; 'the base of the skull' incisura, incisure - (anatomy) a notch or small hollow distal - situated farthest from point of attachment or origin, as of a limb or bone proximal - situated nearest to point of attachment or origin; 'the proximal end of a bone' distal - directed away from the midline or mesial plane of the body mesial - being in or directed toward the midline or mesial plane of the body mesomorphic, muscular - having a robust muscular body-build characterized by predominance of structures (bone and muscle and connective tissue) developed from the embryonic mesodermal layer oral - of or involving the mouth or mouth region or the surface on which the mouth is located; 'the oral cavity'; 'the oral mucous membrane'; 'the oral surface of a starfish' aboral - opposite to or away from the mouth; 'the aboral surface of a starfish'
2.	anatomy - alternative names for the body of a human being; 'Leonardo studied the human body'; 'he has a strong physique'; 'the spirit is willing but the flesh is weak' chassis, human body, material body, physical body, bod, build, physique, figure, flesh, shape, soma, frame, form individual, mortal, person, somebody, someone, soul - a human being; 'there was too much for one person to do' human, human being, man - any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage body, organic structure, physical structure - the entire structure of an organism (an animal, plant, or human being); 'he felt as if his whole body were on fire' person - a human body (usually including the clothing); 'a weapon was hidden on his person' adult body - the body of an adult human being female body - the body of a female human being
3.	anatomy - a detailed analysis; 'he studied the anatomy of crimes' analysis - an investigation of the component parts of a whole and their relations in making up the whole

anatomy

noun

anatomy

noun

anatomy

[əˈnætəmɪ]N

anatomy

[əˈnætəmi]n

anatomy

anatomy

(əˈnӕtəmi) nounanatomical (ӕnəˈtomikl) adjectiveˌanaˈtomically adverbaˈnatomist noun

a·nat·o·my

n. anatomía, ciencia que estudia la estructura del cuerpo humano y de sus órganos;

Anatomy Meaning

anatomy

Anatomy Of The Heart

n anatomía
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