Other muscle groups attach to the upper and lower limb bones. We have more than 600 skeletal muscles. Most attach to the bones, but some like the facial muscles attach to the skin. Trunk muscles are the muscles of abdominal wall, thorax, backbone and pelvic cavity. Other muscle groups attach to the upper and lower limb bones.
Blood cells originate from the stem cells which are located in bone marrow.
Blood cells Lymphatic system supplements blood circulation and protects the body against infections by delivering pathogens and cellular debris to lymph nodes - the disposal centers for such waste and dangerous products. It also brings back to blood vessels water and plasma proteins that have leaked away from blood. Lymph vascular system Digestive system provides food and water to the body tissues. In the mouth food is chewed, then stored and partially digested in the stomach. In the small intestine most of useful substances enter the body tissue.