SKELETAL SYSTEM STRUCTURE Learning Objectives 1 To be

SKELETAL SYSTEM STRUCTURE Learning Objectives 1. To be able to describe the functions of skeletal system. 2. To be able to describe the structure of bones within the skeletal system. 3. To be able to explain the use of the skeletal system within sport. Content 1. 1. 1 The functions of the skeleton applied to performance in physical activities and sports: protection of vital organs; muscle attachment; joints for movement; platelets; red and white blood cell production; storage of calcium and phosphorus 1. 1. 2 Classification of bones: long (leverage); short (weight bearing); flat (protection, broad surface for muscle attachment); irregular (protection and muscle attachment), applied to performance in physical activities and sports 1. 1. 3 Structure: cranium; clavicle; scapula; five regions of the vertebral column (cervical, thoracic, lumbar, sacrum, coccyx); ribs; sternum; humerus; radius; ulna; carpals; metacarpals; phalanges (in the hand); pelvis; femur; patella; tibia; fibula; tarsals; metatarsals; phalanges (in the foot); and their classification and use applied to performance in physical activities and sports

Functions of the skeletal system Protection The skeleton protects vital organs which is extremely important in sport. • The ribs and sternum protect heart and lungs. • The cranium protects the brain. Storing Minerals The bones store calcium and phosphorus which are important for keeping bones healthy and reducing the risk of osteoporosis. • If bones were not strong, performers would not be able to withstand the forces of sport, such as a fall from a judo throw. Osteoporosis is a condition where bones become brittle and more like to break.

Functions of the skeletal system Formation of Blood Cells Platelets, red blood cells and most white blood cells are produced in the bone marrow. • Platelets help to stop bleeding following a cut in their sport. As they reach the site of the cut they stick together to block the tear and stop any further loss of blood. (See here) • White Blood Cells carry antibodies that fight against bacteria, viruses and germs to help prevent infection. • Red Blood Cells carry the oxygen that performers need to produce energy for prolonged periods of time. Movement All of the complex movements involved in sport are a combination of our bones and muscles working together. (The different types of movement are covered later in the unit)

Bones of the Skeleton You will need to know the names and location of these major bones so that you can refer to them when describing sporting movements/actions.

Classification of Bones All of the bones in the body can be classified into one of four groups according to their function – long, short, flat or irregular. Long bones: are longer in length than they are wide and work as levers to produce movement. Short bones: are box shaped as they are as wide as they are long and they are designed for strength, to bear weight and absorb shock. Flat bones: are normally flat, thin and curved. They are a source of protection and also provide a large area for muscles to attach to. Irregular bones: are bones that don’t fit the description of the other three types. They are also used for protection and muscle attachment.

The Vertebral Column The vertebral column is made up of 5 regions. • Cervical • Thoracic • Lumbar • Sacral • Coccyx In each region the bones are different sizes and shapes, and are all irregular. They start off smaller at the neck and increase in size as they have to support more body weight.

Regions of the Vertebral Column Cervical Vertebrae (C 1 – C 7) C 1 is called Atlas – it supports the weight of the head and allows us to nod or head. C 2 is called Axis and allows us to shake or head. The cervical region provides attachment point for muscles (such as trapezius) and allows the most movement of the regions. Thoracic Vertebrae (T 1 – T 12) The main function of this region is to protect the heart and lungs - they join to the ribs to support this. There is movement – but not very much – so there are still muscles attached (e. g latissimus dorsi).

Regions of the Vertebral Column Lumbar Vertebrae (L 1 – L 5) The individual vertebrae within this region are the biggest, as they have to support the most weight. They are also used for movement so have muscles attached (e. g latissimus dorsi) Sacral Vertebrae The individual vertebrae in this region are fused together to make the sacrum. The sacrum transmits the body weight to the pelvic girdle. Coccyx Also known as the “tailbone”. It supports us when in a seated position. It provides a site for muscle attachment (e. g pelvic floor muscles).

Functions of the Vertebral Column The following movements are allowed at the spine due to the jointed vertebrae: • Flexion (bending forward) • Extension (bending backward) • Lateral Flexion (bending sideways) • Rotation (twisting and turning) Discs of cartilage sit between the vertebrae that move. In sport the vertebral column allows us to: • Move our head (Cervical) to perform specific techniques e. g spotting a landing/rotation. • Protection of heart and lungs by Thoracic vertebrae when landing e. g judo. • Move (due to attached muscles) by flexing, extending or rotating as required. • Weight bear through our Sacral vertebrae while running.

Discuss with a partner how the vertebral column contributes to these skills.

Questions 1. Explain the role of platelets in our blood during contact sports such as rugby. (2 marks) 2. Name describe a condition that could arise from a lack of calcium. (2 marks) 3. Name the 2 long bones of the lower leg (2 marks) 4. Lumbar, Sacral and Coccyx are all regions of the vertebrae. Name the other regions and explain their main role. (4 marks)

Explain the role of platelets in our blood during contact sports such as rugby. (2 marks) • Skin is broken during impact, causing bleeding. • Platelets bind to plug the wound and prevent further bleeding. Name describe a condition that could arise from a lack of calcium. (2 marks) • Osteporosis. • Bones are brittle/weaker and more likely to break. Name the 2 long bones of the lower leg. (2 marks) • Tibia • Fibula Lumbar, Sacral and Coccyx are all regions of the vertebrae. Name the other regions and explain their main role. (4 marks) • Cervical • Support for and movement of head. • Thoracic • Protection of heart and lungs.