biology presentation for the skeleton :: essays research papers

Intro slide 1 acetate rayon 1The skeleton of a human foetus is make from tough but flexible cartilage that acts as a draft for bone construction. During ossification ( the changing of cartilage to bone) which begins before birth, the cartilage is illogical down and the resulting space is filled by bone building mineral salts and protein fibres secreted by bone cells.Humans have a bony endoskeleton make up of 206 drum, although we ar born with up to 300, but many of these aggregate during childhood. slide 2 The skeleton is divided into two parts the axile and the appendiculur.Axial skeleton The axial skeleton consists of the skull, backbone and rib confine which forms the upright axis of the body. It helps to protect the brain, spinal cord and organs in the chest.Appendicular skeletonThe appendicular skeleton consists of the upper and lower limbs and the pectoralis (shoulder) and pelvis and girdles. The human pelvis is equal for an upright stance. the lower limbs reasse rt the upper body and enable walking and other locomotory questions to take place, where as the upper limbs ar used for manipulation.Slide threeJust infer off screenSlide four acetate 2Muscles are used to move your bones. Most muscles are joined at twain ends to bones. They are joined to bones by non elastic tendons. Bones are held in place by sloshed fibres called ligaments.Slide five acetate 3Joints are formed when two or more bones come together. Most joints lease bones to move. The amount of movement depends on the type of joint. The elbow joint is a hinge joint. Joints that allow movement are called synovial joints. A synovial joint s adapted to enable a joint to move easily. They contain cartilage, ligaments, bones, synovial bland and a synovial membrane. Slide six The bones provide the unbendable base on which the tendons and ligaments are fixed. They are very resistant to be monotone, bent and stretched.The cartilage is the smooth layer which do bys the ends of the bones and which stops the bones rubbing together. It has high tensile strength, but it is not rigid. Can compressed and is able to act as a shock absorber.The ligaments are strong fibres that hold bones firmly together. they form a protective cover around the joint. Are very strong and sufficiently elastic to allow movement when the bones in the joint move, so reducing the guess of dislocating a joint.