According to About.com, water makes up between 65 and 90 percent of all cells in the human body. The remaining elements by mass include oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, chlorine, sodium, magnesium and trace amounts of iron, cob...
According to the Library of Congress, the human body has at least 650 skeletal muscles and as many as 840 depending on what counts as a muscle. Some sources count complex muscles as a single muscle, while others count complex muscles' individual parts as separate muscle...
Anatomists enumerate about 22 organs in the human body. Mainstream science designates five vital organs, including the brain, heart, kidneys, liver and lungs. Some educators raise the count of vital organs to ten, adding the pancreas, reproductive organs, stomach, small...
In the human body, a motor unit consists of a single motor neuron and all the skeletal muscle fibers it innervates. The axonal terminal of the motor neuron interfaces with skeletal muscle at the neuromuscular junction (NMJ).
Food is needed by the human body for energy, to repair and build cells and to prevent sickness and heal from it. While it is possible to obtain nutrients in a scientifically controlled manner, common food is the most efficient way of obtaining energy and nutrients.
The brain is important in the human body because it allows a person to think, feel and store memories, and it controls and coordinates the body’s actions and reactions, states the Atlanta Brain and Spine Care. The brain is an incredibly complex organ composed of many pa...
According to HowStuffWorks, nitrogen is important to humans and all other living organisms because it is an important component of amino acids. Humans use amino acids to build proteins that form the building blocks of many biological tissues.