Health and Fitness: Human Anatomy

From The Human Body Book

The skeleton makes up almost one-fifth of a healthy body’s weight. This flexible inner framework supports all other parts and tissues, which would collapse without skeletal reinforcement. The skeleton also protects certain organs, such as the delicate brain inside the skull....

From The Human Body Book

Muscles are the body’s “flesh”. They bulge and ripple just under the skin, and are arranged in criss-crossing layers down to the bones. Their job is to contract and pull the bones to which they are anchored. Rarely working alone, they usually contract in groups, moving bones at accurate angles and by precise

From The Human Body Book

The heart is a powerful organ about the size of a clenched fist. Located just to the left of centre in between the lungs, it operates as two coordinated pumps that send blood around the body...

From The Human Body Book

he brain, in conjunction with the spinal cord, regulates both non-conscious processes and coordinates most voluntary movement. Furthermore, the brain is the site of consciousness, allowing humans to think and learn...

From The Human Body Book

The respiratory system, in close conjunction with the circulatory system, is responsible for supplying all body cells with essential oxygen and removing potentially harmful carbon dioxide from the body...

From The Human Body Book

The digestive system consists of a long passageway, known as the alimentary canal or digestive tract, and associated organs, including the liver, gallbladder, and pancreas. The digestive tract starts at the mouth and continues through the oesophagus...

System of vessels in an animal's body that transports essential substances (blood or other circulatory fluid) to and from the different parts of the body. MORE

In the body, all the organs and tissues involved in the digestion of food. MORE

Body control system composed of a group of glands that maintain a stable internal environment by producing chemical regulatory substances called hormones. MORE

The adaptable system of body defenses centers on specialized white blood cells called lymphocytes. These respond to invasion by varied microorganisms.

Network of vessels carrying lymph, or tissue-cleansing fluid, from the tissues into the veins of the circulatory system. The lymphatic system functions along with the circulatory system in absorbing nutrients from the small intestines.

From The McGraw-Hill Concise Encyclopedia of Science and Technology

The muscular system consists of muscular cells, the contractile elements with the specialized property of exerting tension during contraction, and associated connective tissues. The three morphologic types of muscles are voluntary muscle, involuntary muscle, and cardiac muscle.

Network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. MORE

In animals, the anatomical organs concerned with production of offspring. MORE

From the Britannica Concise Encyclopedia

Organ system involved in respiration. In humans, the diaphragm and, to a lesser extent, the muscles between the ribs generate a pumping action, moving air in and out of the lungs through a system of pipes (conducting airways), divided into upper and lower airway systems

Group of organs of the body concerned with excretion of urine, that is, water and the waste products of metabolism. MORE

Soft tissue filling the spongy interiors of animal bones. Red marrow is the principal organ that forms blood cells in mammals, including humans. As the skeleton matures, fat-storing yellow marrow displaces red marrow in the shafts of the long bones of the limbs.

The supervisory center of the nervous system in all vertebrates. MORE

Muscular organ that rhythmically contracts to force blood around the body of an animal with a circulatory system. MORE

Muscular hoselike portion of the gastrointestinal tract extending from the lower end of the stomach (pylorus) to the anal opening. MORE

Either of a pair of organs at the back of the abdomen whose function is the removal of waste pro-ducts from the blood, and the excretion of such compounds from the body, usually in the form of urine. MORE

Largest glandular organ of the body, weighing about 3 lb (1.36 kg). MORE

In mammals, large cavity of the body, used for gas exchange.

Glandular organ that secretes digestive enzymes and hormones. MORE

Saclike dilation in the gastrointestinal tract between the esophagus and the intestines , forming an organ of digestion. MORE

From Dorland's Illustrated Medical Dictionary

A large glandlike but ductless organ in the upper part of the abdominal cavity on the left side. It is the largest structure in the lymphoid system.

Organ of hearing and equilibrium. The human ear consists of outer, middle, and inner parts.

Organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation.

From the The Hutchinson Unabridged Encyclopedia with Atlas and Weather Guide

The organs of smell are confined to a small area in the roof of the nasal cavity. The olfactory cells are stimulated when certain molecules reach them.

The flexible tissue (integument) enclosing the body of vertebrate animals. In humans and other mammals, the skin operates a complex organ of numerous structures (sometimes called the integumentary system) serving vital protective and metabolic functions.

From Taber's Cyclopedic Medical Dictionary

A freely movable muscular organ that lies partly in the floor of the mouth and partly in the pharynx. It is the organ of taste and contributes also to chewing, swallowing, and speech.