Human anatomy and the body's systems

Human anatomy is the study of the structure of the body and the arrangement of its parts, while physiology examines how those parts function. The body is organised into levels of increasing complexity: cells form tissues, tissues combine into organs, and organs that work together form organ systems. This hierarchy makes a large and intricate body easier to understand by grouping its many structures according to the tasks they perform.

Several major systems carry out the body's essential work. The skeletal system of bones gives the body its frame, protects organs and provides attachment points for muscles. The muscular system produces movement, including the facial muscles that drive expression. The nervous system, centred on the brain and controlled through nerves, gathers information and coordinates responses, while the cardiovascular system, driven by the heart, circulates blood to deliver oxygen and nutrients and remove waste.

Other systems handle further vital roles: the respiratory system, including the larynx and lungs, exchanges gases; the digestive system breaks food down for absorption, with the salivary glands beginning the process; and the reproductive system enables the continuation of life. Anatomy is often studied region by region as well, examining areas such as the skull, neck, shoulder, hand and wrist, the vertebral column and the pelvis, along with sense organs like the eye and ear. Genetics underlies it all, since the DNA in every cell carries the instructions that build and run the body.

Frequently asked questions

What is the difference between anatomy and physiology?

Anatomy describes the structure and arrangement of the body's parts, while physiology explains how those parts work and interact.

How is the human body organised?

Cells form tissues, tissues form organs, and organs that cooperate make up organ systems such as the skeletal, muscular and nervous systems.

What does the nervous system do?

Centred on the brain and acting through nerves, it gathers information from the body and surroundings and coordinates the body's responses.