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 distances.
From The Human Body BookThe 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 lonThe digestive system consists of a long passageway, known as the alimentary canal or digestive tract, and associated organs, including the liver, gallbladder, and pancreas.
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 human body book: An illustrated guide to its structure, function and disorders
Muscle tissue creates bodily movements and it also powers internal processes, from the heartbeat and the movement of food through the intestines to the adjustment of artery diameter and focusing the eye.
From Britannica Concise EncyclopediaOrgan 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.
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 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.