This system circulates blood throughout the body

(a)  

The system that breaks down the components of food into smaller components that can be absorbed and taken into the body

(a)  

This system senses changes in the external environment and creates a reaction to them

(a)  

This system's function is primarily to provide oxygen to body tissues for cellular respiration, remove the waste product carbon dioxide, and help to maintain acid-base balance.

(a)  

The glands of this system secrete hormones, which are biological molecules that regulate cellular processes in other target tissues, so they require transportation by the circulatory system. Adequate nutrition is critical for the functioning of all the glands in this system.

(a)  

This system involves cleansing the blood and ridding the body of wastes.

There are additional, equally important functions played by this system. Take for example, regulation of pH, a function shared with the lungs and the buffers in the blood. Additionally, the regulation of blood pressure is a role shared with the heart and blood vessels.

(a)  

This system allows the body to move voluntarily, but also controls involuntary movements of other organ systems such as heartbeat in the circulatory system and peristaltic waves in the digestive system

(a)  

This system provides structural support and protection for all the other organ systems in the body.

It also synthesizes red and white blood cells and platelets in bone marrow.

Another vital function is that the structures of this system act as a storage depot for minerals such as calcium, phosphorous, and magnesium

(a)  

This system is also referred to as the immune system, and has its own vessel network with glands

(a)