Learn the functions of the skeletal system.
The human skeletal system has 206 bones. The bones exist throughout the body, from the skull in the bones of the head to the bones in the toes. Some bones are small and others are large. Altogether, the skeletal system has many functions, including protection, assisting movement and blood cell production.
Protection
Vital organs are protected by the skeletal system. Starting at the top, the cranial bones, or cranium, protect the brain. The vertebrae (spinal column) encase the spine and also provide flexibility for movement. The rib cage and sternum offer protection for the heart, lungs and some digestive organs and allow for expanding and contracting as we breathe. The pelvis protects and also supports the digestive organs and reproductive organs. Bones also protect the marrow.
Movement
Three systems of the body act together to produce movement: the nervous system, muscular system and skeletal system. The nervous system sends the electrical impulses to tell the muscles to move, and the skeletal system acts as anchors and levers for the action. Some muscles will contract, while others will relax. In movement, there is a starting point, or the anchor, and an ending point, or the insertion. The anchor is the bone that remains stationary and the insertion is the bone that moves. Tendons connect muscles to bones, and ligaments connect bones to other bones at the joints. Since the muscular and skeletal systems work together, they can be grouped together as the musculoskeletal system.
Blood Cell Protection
Red and white blood cells are produced in the red marrow of the long bones in our body. This is called hematopoiesis. This is essential for our immune and circulation systems. The bone marrow stem cells are constantly dividing, making millions of cells that turn into red and white blood cells. Approximately 2.6 million red blood cells are produced each second to replace those that are worn out or destroyed by the spleen. If the marrow is making approximately the same number of cells as the spleen destroys, then there is perfect balance. Bone marrow is a soft, spongy tissue. As we age, about half of that marrow turns to yellow marrow, which is composed of fat cells. In the case of extreme blood loss, the body can change some of the yellow marrow back into red marrow to increase red blood cell production.
Tags: skeletal system, blood cells, blood cell, blood cell production, blood cells produced