Organ Systems

Organ Systems Learning Objectives

  • List the organ systems of the human body, and identify the main organs for each.

In this lesson, you will learn about the organ systems that are necessary for the vital functions of life. You will also get a chance to practice using body planes and directional orientations to explain the anatomical integration and relative location of structures within organ systems. The next section will systematically describe the organ systems of the body, as well as the major anatomical structures and functions.

Organ System is defined as an integrated collection of organs in the body that work together to perform a vital function. This course will organize the organ systems of the body based on the vital functions defined earlier.

The major organ systems of the body are shown in the table below.

Major Organ Systems of the Body Grouped by Primary Function
Function Organ System
Exchange with the Environment Digestive System
Respiratory System
Fluid Transport within the Body Cardiovascular System
Lymphatic System and Immunity
Urinary System
Structure, Support, Protection and Movement Integumentary System
Skeletal System
Muscular System
Control and Regulation Nervous System
Endocrine System
Skeletal System

As an example of how the components of an organ system work together, let’s look at the skeletal system. The most obvious components of this system are the bones, which form a rigid framework for the body. The bones contribute to our ability to stand upright and move around, but they can’t do it alone. Ligaments and cartilage are also parts of the skeletal system. Ligaments connect the bones to each other. Cartilage cushions the spaces between the bones, allowing for smooth movement. And the bones couldn’t move at all without the skeletal muscles, and tendons that connect muscles to bones (parts of the muscular system). The bones provide the muscles with something to pull against.

If one component of an organ system is damaged or malfunctions, the function of the organ system will be affected. Think about a broken bone. If the femur breaks, it will be much harder to maintain an upright posture, or to walk or run. These might also be more difficult if the cartilage of the femur is destroyed by arthritis or a ligament in the knee is injured while playing a sport. If any component of the skeletal system is damaged—bone, ligament or cartilage—the knee will not function properly.


The sections that follow will describe the details of the organ systems that perform the vital functions of life. You will learn how they contribute to homeostasis and how imbalances in homeostasis lead to various disease states.