According to Essentials of Human Anatomy & Physiology: Essentials Of Human Anatomy And Physiology, The skeletal system is one of the most important systems of our body. If we didn’t have our internal skeleton, we would just be a puddle. We wouldn’t be able to stand up, walk or even move the way we move now.
Kids Health states that bones have many different purposes in our body. The Skeletal System consists of fused and individual bones that support and provide protection to muscles, and to organs such as the brain, lungs, and heart. The backbone provides the structure backbone provides the structure for us to stand straight. Bones serves as levers for the muscles to pull on to cause movement at joints. The bones also stores calcium, fats and other substances for the body. The skeleton contains red marrow, the side of blood cell production.
The bones are classified into four groups, the long, short, flat, and irregular a stated by the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health It is also divided into two parts, the Axial and Appendicular skeletons:
- The Axial Skeletal Forms the longitudinal axis of the body and it can be divided into three parts: the skull, the vertebral column, and the bony thorax, which are the ribs and the sternum.
Axial skeleton is shown in green
- Is made up of two sets of bones
- Cranium – encloses & protects brain
- Facial bones – holds eyes in anterior position & allows the facial muscles to show emotions.
- The Appendicular Skeleton is composed of 126 bones of the limbs the pectoral, and pelvic girdles, which attach the limbs to the axial skeleton. It’s divided into four sections. They are: bones of the shoulder girdle, bones of the upper limbs, bones of the pelvic girdle, and bones of the lower limbs. Bones of the shoulder girdle consist f two bones – a clavicle and a scapula. Bones of the upper limbs consist of the arm, forearm, and hand.
According to Essentials Of Human Anatomy & Physiology: Essentials Of Human Anatomy And Physiology A joint, also called an articulation, is where two bones meet. Joints have two functions: they hold the bones together securely but also give the rigid skeleton mobility.
- The fibrous joints are immovable joints. These joints are firmly held together by a thin layer of strong connective tissue. The sutures of the skull and the teeth in their sockets are an example of fibrous joints.
- Cartilaginous joints are joints that are attached to each other by means of white fibrocartilaginous discs and ligaments, which allow only a limited degree of movement.
- Synovial joints allow for much more movement than cartilaginous joints. Cavities between bones in synovial joints are filled with synovial fluid. This fluid helps lubricate and protect the bones.
- A hinge joint allows extensions and retraction of an appendage, while pivot joints allow rotation around an axis. The neck and forearms have pivot joints. In the neck the occipital bones spins over the top of the axis. In the forearms that radius and ulna twist around each other.
- A saddle joints allows movement back and forth and up and down, but does not allow for rotation like a ball and socket joint.
- Ball-and socket joints are formed where the rounded head of one bone fits into the hollow, cup-shaped socket of anther bone such as the shoulder joint and the hip joint. Such joints allow freedom of movement in all directions.