The skeleton provides a frame for these to connect to, which allows for body movement.
Muscles
The circulatory system is a system of these that pass through your entire body to reach every cell.
Vessels
This system is usually the first line of defense against disease, providing a physical barrier to viruses.
Integumentary System (Skin)
This system includes the brain and spinal cord and provides instruction to all other tissues.
Nervous System
This process begins with chewing, which is a form of mechanical digestion that grinds food into a pulp.
Digestive System
These two systems interact when the mouth and pharynx are used to both swallow food and breathe air.
Digestive and Respiratory
When you breathe, the circulatory system carries oxygen to cells and carries this dissolved waste gas back to the lungs.
Carbon Dioxide (CO2)
Red and white blood cells are created in this part of the skeletal system.
Bone Marrow
The endocrine system is described as the "chemical brother" to this other system.
Nervous System
These smooth muscles help move food through your intestines.
Digestive system muscles
The circulatory system delivers these chemical signals, created by the endocrine system, to cells throughout the body.
Hormones
Unlike the circulatory system which moves blood in a loop, the lymph system moves fluid in this many directions.
One direction
These structures near the surface of the skin open to cool the body down and close to conserve heat.
Capillaries
This gland at the base of the skull releases hormones that control blood pressure and the excretory system.
Pituitary gland
Blood passes through these two bean-shaped organs to have urea and uric acid removed.
Kidneys
While the Digestive system removes undigested solids, this system filters compounds from the bloodstream to produce urine.
Excretory System
The lymph system connects to this specific large vein to return fluid to the heart.
Superior Vena Cava
This system is "relatively invisible" and made of many different cell types that patrol every organ and tissue.
Immune System
This gland in the neck controls your metabolism and the rate of bone growth.
Thyroid gland
This branching point structure directs food to the stomach and air to the lungs.
Epiglottis
The endocrine system interacts with this system when the hypothalamus sends messages to the pituitary to trigger the production of sperm and eggs.
Reproductive System
The lymph system transports this specific type of infection-fighting cell.
White blood cells
These glands in the skin secrete sweat and oil but are NOT part of the endocrine system.
Exocrine glands
The nervous system interacts with the respiratory system in this organ to allow for the sense of smell.
Nose
In the excretory system, most of this substance is put back into the system after being filtered from the blood.
Water