Cambridge tech The skeletal system

• Cranium
• Sternum
• Ribs 
• Vertebrae column
• Cervical vertebrae
• Thoratic vertebrae
• Lumbar vertebrae
• Sacrum
• Coccyx

The function of the axial skeleton is to protect the organs that lie within it.

• Clavicle                                  
• Scapula                                 
• Humerus
• Radius
• Ulna
• Carpals
• Metacarpals
• Phalanges
• Pelvis
• Ilium
• Ishium
• Pubis
• Femur
• Patella
• Tibia
• Fibula
• Talus
• Tarsals
• Metatarsals

The appendicular skeletons function is the movement of the human body

• Shape. Your bones give you shape, including defining the shape of your face and how tall you are.
• Support. Your skeleton also provides support for your organs, something for them to attach to or suspend from, how the ribs are attached to the lungs supporting them by kepping them open.
• Protection. Your bones provide essential protection, if the brain wasnt cocered by the cranium, it would be vulnerable.
• Movement. Bones provide the attachment points for muscles that make the bones move.
• Blood cell production. As well asbeing incredibly strong, bones are also lightweight. This is because they are not solid. Inside bones is a central core of marrow, where red and white blood cells are created.
• Mineral storage. Your bones also provide a place for your body to store calcium and phosphorous, which can be used later in other parts of the body for other functions such as nerve transmission and metabolism.

• Long bones.  Bones that are longer than they are wide, The femur
• Short bones. Bones that are short and almost cubic in shape, The carpal bones 
• Flat bones. Bones that are flatter than they are wide, The scapula
• Irregular bones. Bones that do not fit into any other category, The vertebrae
• Sesamoid bones. Simular to short bones however they are within a tendon, The patella

They allow no movement. A fixed joint is important in allowing our skeleton to grow and develop, with an example being your cranium. As a child, your cranium protects your brain but also needs to grow with the rest of your body, reaching 90% of adult growth by age 1 and 100% by the age of 7. To achieve this, the bones of the cranium grow and develop to accomodate the brain. Fusing fully once fully grown.

They join bones together with cartilage only. These joints allow small movements, usually in a number of different directions. A good example of a cartilaginous joint is the vertebrae of the spine. Each vertebra is able to move slightly against each other; however, as you inrease the number of vertebrae the range of movemetn increases overall.

They allow a much more greater range of movement, and these types are further subdivided on the kind of movement they are able to achieve.

• Hinge joints move in one plane e.g elbows, knees and ankle 
• Ball and socket joints allow movement in 4 planes e.g shoulder and hip
• pivot joints move in one plane. The bones move together as a pin in a grove e.g neck and radioulna
• Condyloid/ellipsoid joints allow movement in 3 planes, and have the apperence of a shallow pestle and mortar e.g wrist
• Saddle joints are strong and allow movement in 3 planes, having the apperence of 2 saddles put together e.g thumbs
• Plane joint/gliding occurs when 2 relativley flat bones come together. They allow little movement in a number of different ways e.g the lower vertebrae, carpals and tarsal bones.

• Articular/hyaline cartilage is hard, smooth and bulish-white in colour, covering the end of the bones where they meet. The smooth and glossy consistency enables bones to move against each other without friction
• Ligaments hold 2 ends of bones together, ensuring stability while enabling while enabling movement. Very strong and slightly elastic.
• Synovial membrane is a layer that lines the synovial joint producing and containing the synovial fluid within in
• Synovial membrane is a thick, white fluid that helps to reduce the friction in a joint
• Menisci are pads of tissue that lie between the articular cartilage and sit within the synovial fluid. They act as shock absorbers, reducing the impact on the bone ends
• Pads of fat also act as friction reducers. In the knee they fill the space below the patella and the ends of the femur and tibia
• Bursae are small sacks filled with fluid. They are located where skin, ligaments or bone could cause friction e.g between the patella and skin on the front of the knee
• Joint capsules are the protectie layers around a joint

• Flexion and extention. The bending of a joint where the bones are brought closer together or moved apart
• Lateral flexion. Refers specifically to the spine, related to bending from side to side
• Abduction and adduction. The movement of a body part away from and towards the midline of the body
• Horrizontal abduction and adduction or horrizontal flexion and extention. Refers specifically to ball and socket joints e.g a forehand drive in tennis
• Medial and lateral rotation. Refers specifically to ball and socket joints; movement away from and toward the midline of the body
• Circumduction. Combination of flexion, extention, abduction and adduction
• Pronation and supination. Refers specifically to the radioulna joint, e.g turning the palm face down or face up
• dorsidlexion and plantar flexion. Refers specifically to the ankle joint; pointing foot and toes towards the ground and up towards the tibia

Ligaments get warmer and are more stretchy.

• Increased range of momement at joints 
• Less likely to be injured 
• Bones heal quicker after an injury
• Increase in synovial fluid 
• More calcium in the bone
• Increased bone density
• Increased mineral content 
• Increased thickness in hyaline cartilage

• Increased osteoblast activity
• Increased range of movement at the joint
• Less likely to be injured