According to Minnesota State University's Emuseum, one of the most important ways the skeletal system works with other systems is via protection. Of particular importance is the skeletal system's ability to protect the central nervous system, which is made up of the spinal cord and the brain. The skeletal system surrounds these organs and safeguards delicate nerve tissue from trauma. The skeletal system also protects the heart and lungs in the chest via the ribs.
The interaction between the skeletal system and the muscular system is so constant that sometimes the two organ systems are referred to as one system--the musculoskeletal system. Skeletal muscles must be attached to something at either end to give them support while they contract. Typically this means each end of a skeletal muscle is attached to a bone. According to Hillendale Health, when a muscle contracts, it brings the two bones closer together. Skeletal muscles are connected to bones via bands of connective tissue called tendons. If a tendon is severed, the muscle no longer has anything to contract against and becomes essentially useless.
The skeletal system is important to the composition of the blood, notes Minnesota State University's Emusuem. Inside the bones is a substance called bone marrow. Bone marrow is responsible for making new blood cells. Red blood cells are needed for the transport of oxygen throughout the body. White blood cells play a critical role in the immune system. Because the bone marrow is the area where these cells are made, problems with the skeletal system can have a huge effect on the hematological system (the blood).
McGraw-Hill notes that the skeletal system also plays an important role in the body's regulation of calcium. Calcium levels in the blood have to stay within a very narrow range for muscles and nerves to work correctly. The skeletal system serves as the biggest reservoir for calcium in the body, which allows the body to get extra calcium when blood levels are low and to deposit excess calcium if too much winds up in the blood. The thyroid and parathyroid glands secrete hormones that tell cells within the bones (osteoclasts and osteoblasts) if calcium needs to be released or stored in the bones.