Breaks down food into nutrients for energy

Includes major organs like the stomach, intestines, and liver

Interacts with the circulatory system by absorbing nutrients into the bloodstream

Transports oxygen, nutrients, and hormones via blood

Heart pumps blood through arteries and veins

Interacts with the respiratory system to exchange oxygen and carbon dioxide in the lungs

Responsible for breathing and gas exchange

Includes lungs, trachea, and diaphragm

Interacts with the muscular system, as the diaphragm contracts to allow breathing

Produces hormones that regulate body functions

Includes glands like the thyroid, pancreas, and adrenal glands

Interacts with the nervous system to regulate responses to stimuli (e.g., stress response via adrenal glands)

Provides structure, movement, and protection

Includes bones, muscles, and joints

Interacts with the nervous system as nerves signal muscles to contract for movement

Controls body functions and transmits signals

Includes the brain, spinal cord, and nerves

Interacts with the endocrine system by regulating hormone release through the hypothalamus

Defends against pathogens and diseases

Includes white blood cells, lymph nodes, and the spleen

Interacts with the circulatory system as immune cells travel via the bloodstream to fight infections

Responsible for producing offspring

Includes testes (male) and ovaries (female)

Interacts with the endocrine system, as hormones regulate reproductive functions