Human Body Systems: Overview, Functions & Organs

Many different human body systems work together to allow our bodies to function and thrive under various positions.  Let’s explore the 11 primary human body systems and review the related processes and organs associated with each system.

Nervous System

Here is where all the information is processed and transmitted throughout the body. It is responsible for the collection of data in the internal and external environment, the processing of the data, and the response. The nervous system has two main components: the central nervous system and the peripheral nervous system. The central nervous system contains the brain and spinal cord, while the peripheral nervous system encompasses the nerves not present in the brain and spinal cord exclusively as this system transmits information to muscles, glands, and other organs.

Endocrine System

This human body system is responsible for the production of chemicals known as hormones, which contain the capability to have systemic effects on the human body. Glands within the endocrine system secrete hormones which are transported through the bloodstream and are able to control actions of organs, cells, and tissues. Generally, glands in this system release hormones directly into the bloodstream. Exocrine glands secrete tears and digestive enzymes, excreted through tube-like structures known as ducts).

Integumentary System

Everyone assumes this is just the skin, but it is so much more than that. This human body system’s purpose is to regulate internal body temperature, protect the body from pathogens, and protect the body from the sun’s UV light. Structures within this system include oil glands, skin, nails, hair, and sweat.

Lymphatic System

The lymphatic system is very important for immunity. This system protects the body from diseases or illnesses, collects fluids lost from blood vessels, and returns them back into the circulatory system. Structures include the spleen, white blood cells, thymus, lymph nodes (glands), lymph vessels, and bone marrow.

Muscular System

This human body system is most important for helping our bodies move. Voluntary movement is achieved when the muscular system works in conjunction with the skeletal system. Also, this system circulates food in the digestive system and blood within the circulatory system. Structural pieces present in this system include cardiac, smooth, and skeletal muscles.

Circulatory System

Circulation is the transportation of nutrients, blood, and oxygen to cells. Also, this human body system is responsible for moving cell excretion, defending the body against infections, and stabilizing body temperature. The blood vessels, heart, and blood are the main components of this system.

Skeletal System

This human body system is primarily involved in making the structure of our body the way it is. This system also has the ability to store materials, specifically mineral reserves, and to have cells that can make blood. The functions of this system focus on the support of the body, by protecting organs within and allowing movement of the body. Structural pieces are tendons, cartilage, bones, as well as ligaments.

Respiratory System

The Respiratory System is responsible for bringing oxygen into the body where it’s needed, which is necessary for cellular respiration and removing excess carbon dioxide within the body. The gas exchange process is also part of this human body system. Structures inside this system are lungs, bronchioles, bronchi, trachea, nose, larynx, and the pharynx.

Digestive System

This human body system is involved in the breakdown of food and nutrients, before passing it off to the other systems. The responsibilities of this system focus on the circulation of food within the body. This includes the excretion of materials that were consumed, the chemical and physical breakdown of foods, and the absorption of nutrients. Structural parts within the digestive system are the stomach, esophagus, pharynx, small and large intestines, rectum, and mouth.

Excretory System

The Excretory System has a primary function to eliminate all variations of waste to maintain homeostasis. The skin, liver, lungs, urethra, kidneys, and urinary bladder all are in this system. Since waste comes from many sources, the skin is responsible for removing waste through sweat and the kidney filters out waste in the blood. There are many other ways the excretory system eliminates waste from the human body.


Reproductive System

The Reproductive System has significant variations between the male and female body. The functions of this system include the development and protection of the embryo and the production of gametes. Organs within this system include the Fallopian tubes, vagina, and the uterus in a female body). In male bodies, there are specific organs that are present such as epididymis, urethra, penis, and the testes.

Author: Maaida Kirmani