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.
E. Muscle Any or all of these layers just described may be involved in infections. 3. DEFENSES OF SKIN AND SOFT TISSUE (review Host Defense Against Bacterial Pathogens: Defenses of Body Surfaces, pp.7-8.) A. Skin is an important anatomic barrier â bacteria and viruses cannot penetrate intact skin.