13 Questions About How the Human Body Works Answered: Quick Facts

Written and fact-checked by

The Information Architects of Encyclopaedia Britannica

Photos and Videos

Pulmonary blood vessels

Several blood bags filled with human blood, labeled with barcodes and volume information, are lined up in storage.

Illustration of a blood vessel with a cutaway view showing red blood cells, white blood cells, platelets, and plasma, each labeled to highlight the main components of blood.

Labeled diagram of the human brain from a side view, highlighting regions for motor, sensory, auditory, visual, and speech functions, including Broca's and Wernicke's areas.

diaphragm; breathing

Detailed cross-section illustration of human skin showing layers including the epidermis, dermis, and subcutaneous fat, with labeled structures such as hair, pores, sweat gland, oil gland, nerves, blood vessels, and hair follicle.

A swimmer wearing goggles and a swim cap turns their head to breathe while swimming in open water, emphasizing the act of breathing during exercise.

See All Videos and Images →

Topics

human body 7 Vestigial Features of the Human Body human nervous system human eye human digestive system human respiratory system renal system human cardiovascular system human endocrine system human sensory reception human reproductive system