Organs of the circulatory system are the heart, blood, and blood vessels (arteries and veins). The circulatory system interacts with other systems, such as the lungs (respiratory system), liver (digestive system), and kidneys (digestive system).
Skin, hair, nails, sweat and oil glands. Function: Serves as a barrier against infection and injury; helps to regulate body temperature; provides protection against ultraviolet radiation from the sun.
The barrier function becomes compromised, so that bacteria, viruses, undigested food particles and toxic waste products can leak from the inside of your intestines through the damaged digestive lining into your bloodstream, where they're transported throughout your body and can trigger your immune system to react.