What is the skeleton? made up of bones -300 at birth  206 by adulthood -why? -some fuse over time (ex. Plates in the skull and lower parts of the vertebral column) The main functions of the skeletal system are: Structural support-support for muscles and skin Protection-protects the sensitive/delicate parts of body (brain, heart, lungs,etc) Growth centre for cells -red blood cells and platelets Reservoir for minerals -stores calcium and phosphorus Movement-contracting muscles pull on bones for movement

Structure of the Skeleton the human skeleton is divided into 2 main sections: the AXIAL and APPENDICULAR AXIAL from “axis”  centreline comprised of the vertebral column (spine), the spinal column and skull the “core” of the body protects the most important parts of the body: heart, lungs, spinal cord, brain, etc most muscles will originate from parts of the axial skeleton

APPENDICULAR think of appendage includes the moveable limbs and the supporting structures (girdles) shoulder pelvis plays a key role in allowing movement There are 5 types of bones you need to be familiar with...

Using page 11 in your text, label each on of these bones, and provide a short description Long bone -found in arms and legs Short bones -commonly found in wrists Flat bones -flat and thin -protect vital organs Irregular bones - “odd-looking” bones not otherwise classified Sesamoid bones -small, flat and wrapped in tendons -glide over body surfaces

The Anatomy of a Bone Bones may look like they are dead, but in fact are very much alive, growing and changing all the time. Before we talk about how bones grow and change, we first need to understand the various parts of a bone. Using figure 2.3 on page 12 in your text, label the picture below, and using the information on page 12, complete the structure function chart. Articular cartilagePeriosteum Cancellous boneMedullary cavity Compact bone Epiphyseal plate EpiphysisDiaphysis (shaft) Epiphysis (head)

StructureFunction Articular cartilage Cancellous bone Epiphyseal plate Medullary cavity Periosteum Compact bone Epiphysis Diaphysis -covers/protects ends of bones; allows smooth movement of joints; no blood/nerve endings -spongy, marrow-filled; will strengthen with resistance training -cartilage at each end of bone (growth plate); allows longitudinal bone growth -inside shaft; contains red and yellow marrow; production of red blood cells -outer connective tissue;covers length of bone; connects bone to bone or muscle -most dense bone; structural integrity happiest -ends of bone; compact; articulates with another bone -thickest part of bone; shaft