Skeletal and Muscular System
The skeletal system could be seen as a super frame which holds the entire body. In absence of this strong structure the body could collapse under the influence of gravity. It protects various key organs in the body. For example, the ribs in the upper body part protect heart and lungs. The skull shields the brain. Comprising of bones and cartilages, the skeletal system supports movement in the body. It also stores minerals like calcium and phosphorous, and release them when needed. In an average adult body, there are 206 long and short bones.
There are 80 bones in the axial skeletal system and 126 in the appendicular skeletal system. While the axial skeleton consists of the bones of the head and trunk, the appendicular skeleton system consists of the bones of the shoulder girdle, the upper limbs, the pelvic girdle, and the lower limbs.
A joint is a place where two bones are fitted together. It is supported by cartilages and reinforced with ligaments. The joints are primarily of three types — fibrous, cartilaginous and synovial. Fibrous joints are immoveable while cartilaginous joints allow some movement. The synovial joints are freely moveable. There are six types of synovial joints — hinge, saddle, plane, pivot, condyloid and ball and socket. Ball and socket joint facilitates a wide range of movements.
The muscles in the body have three main functions — movement, production of heat and maintaining postures. Most muscles such as skeletal muscles in the body are voluntary which means they can be moved as per a person’s will. But there are involuntary muscles such as cardiac muscles which are involuntary. This means they cannot be controlled by conscious thought.
There are three different types of muscles namely skeletal, cardiac and visceral. There are about 700 muscles that are connected to the bones of the skeletal system. The skeletal muscles help in a wide range of physical actions such as running, walking and lifting. Cardiac or heart muscles are responsible for pumping of the heart. It is therefore vital for circulation of blood across the body. The visceral muscles are involuntary and are found within organs such as intestines. These muscles help in the transportation of materials within the organs.