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VCE Physical Education Unit 1. SKELETAL SYSTEM. Human Skeleton. FUNCTIONS. SUPPORT - organs and tissues of the body are held in place by the skeleton. PROTECTION – provides a rigid surface for protection of vital organs ie. cranium protects the brain
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VCE Physical EducationUnit 1 SKELETALSYSTEM
FUNCTIONS • SUPPORT - organs and tissues of the body are held in place by the skeleton. • PROTECTION – provides a rigid surface for protection of vital organs ie. cranium protects the brain • MOVEMENT – bones provide a base for muscle attachment. It allows movement of the body through using the bones as levers. • PRODUCTION & STORAGE – bones provide a site for manufacture of red & white blood cells and storage of minerals. Ie.calcium
STRUCTURE OF SKELETON • There are about 206 bones found in an adult skeleton. • The bones are divided into two main groups (1) AXIAL SKELETON (2) APPENDICULAR SKELETON
AXIAL SKELETON • The axial skeleton forms the basic structure supporting the rest of the skeleton. • It consists of: • Skull • Vertebral column • Rib cage
AXIAL SKELETON SKULL Cranium consists of 8 bones fused together. Face has 14 bones. Most are fused, whilst others like the mandible (lower jaw bone) can move independently
AXIAL SKELETON VERTEBRAL COLUMN Divided into 5 main regions • Cervical spine (7) • Thoracic spine (12) • Lumbar spine (5) • Sacrum (5) • Coccyx (4) The 5 sacrum vertebrae and 4 coccyx vertebrae are fused to form one solid bone.
AXIAL SKELETON • ATLAS – first cervical vertebra • AXIS – second cervical vertebra • Spinal chord runs down the canal formed by the vertebra being stacked on top of one another. • Intervertebral Discs are found between each vertebrae and keep spine flexible and they absorb shock • Coccyx remnance of a tail
AXIAL SKELETON THORAX • 12 pairs of ribs • Joined to thoracic vertebrae • Top 10 ribs joined to sternum • Remaining two have “free” ends – ‘floating’
APPENDICULAR SKELETON • Forms mainly the extremities of the body and their connections to the axial skeleton • Consists of - limbs (arms & legs) - shoulder and pelvic girdles
APPENDICULAR SKELETON THE ARM AND HAND
APPENDICULAR SKELETON THE LEG AND FOOT
TYPES OF BONE TISSUE • COMPACT BONE TISSUE • Heavy, dense, strong bone tissue • Ivory appearance & covers the complete bone • Thickest at the centre of the shaft
TYPES OF BONE TISSUE (2) CANCELLOUS BONE TISSUE or “spongy bone” • Honeycomb appearance • Strong, hard & less dense than compact bone • Found mainly ends of bones
TYPES OF BONES Bones are classified into 5 groups according to their shape: • LONG BONES – incl. humerus, radius, tibia and phalanges • SHORT BONES – incl. carpals and tarsals • FLAT BONES – incl. skull, pelvis, ribs and shoulder blades (Flat bones protect vital organs and provide sites for muscle attachment) • IRREGULAR BONES – incl. facial and vertebrae • SESAMOID BONES – incl. patella (bones which are found encased by muscle)
TYPES OF BONES Short bones (carpals)
BODY GROWTH • Changing rate of growth to the body is affected by two things – height and weight. • Differs from time to time during life and differs for various body parts.
LONG BONE GROWTH Two growth processes responsible for done development. First process: • OSTEOBLASTS (bone builders) – add bone to the outside surface, enlarging and elongating the bone. • OSTEOCLASTS (bone eaters) – tunnel out the marrow cavity and internal spaces (these work at the same time as osteoblasts.) Second process (greatest growth occurs): • EPIPHYSEAL PLATES (growth plates) found at either end of the bone where the shaft (diaphysis) meets the head or base (epiphysis). These growth plates are made of cartilage cells which multiply rapidly and the outside cells ossify, increasing the length of the shaft.
SKELETAL SYSTEM Reference: VCE Phys Ed Book 1 (your text) Chapter 1 pg 3-10 The End