The Skeletal System :The Skeletal System Functions and Structures


Skeletal System :Skeletal System Provides a basic framework for your body Made up of bones and joints


Functions :Functions Provides a living structure for your body Protects your internal tissues and organs from trauma Store minerals such as calcium and phosphorus Plays role in movement by providing a strong, stable, and mobile framework on which muscles can attach and work from.


Structures :Structures Axial 80 bones Skull Spine Ribs Vertebrae sternum Appendicular 126 bones upper and lower limbs Shoulders hips 206 bones classified in two main groups


Diagrams :Diagrams Axial Appendicular Image source: http://embryology.med.unsw.edu.au/notes/skmus7.htm Image source: http://facstaff.gpc.edu/~jaliff/anathom.htm


Bones :Bones Made up of layers Outer layer is hard, densely packed, compact bone Inner layer is spongy, less dense with cavities fills with red bone marrow Categorized by shape Long, short, flat, irregular Image source: http://www.dartmouth.edu/~humananatomy/figures/chapter_2/2-1.HTM


Types of Bones :Types of Bones Long bones = arms and legs Humerus, femur Short bones = equal length and width Wrist, ankle Flat bones = thinner, flatter - often protect internal organs Skull, scapula, ribs Irregular bones Facial, vertebrae


Cartilage :Cartilage Strong, flexible connective tissue Another part of skeletal system Found at ends of long bones, end of the nose, within the outer ears In joints, it acts as a cushion, reducing friction and allowing smooth movement


Joints :Joints Defined as where bones meet Some don’t move like space between skull bones Some have limited movement such as vertebrae Some are flexible in their movement with various limitations


Flexible JointsBall and Socket :Flexible JointsBall and Socket Formed when round head of bone fits into rounded cavity of adjoining bone Hip, shoulder Widest range of motion Images source: http://ovrt.nist.gov/projects/vrml/h-anim/joint1C.gif Image source: http://teachers.saschina.org/rderozario/files/2009/03/ballsocketjoint.JPG


Flexible JointsHinge :Flexible JointsHinge Elbow, knee, ankle, and fingers Allowed to bend and straighten, promoting rotation Image source: http://ovrt.nist.gov/projects/vrml/h-anim/joint1A.gif


Flexible JointsPivot :Flexible JointsPivot Limited rotation or turning of the head Image source: http://content.answers.com/main/content/img/oxford/Oxford_Sports/0199210896.pivot-joint.1.jp


Flexible JointEllipsoidal :Flexible JointEllipsoidal Wrist Oval-shaped part that fits into a curved space Gliding joints allow bones to slide over one another Image source: http://ovrt.nist.gov/projects/vrml/h-anim/joint1E.gif


Other Parts of Joints :Other Parts of Joints Ligament Band of fibrous, slightly elastic connective tissue that attaches bone to bone Help stabilize the movements of bones at a joint Tendon Fibrous cord that attaches muscle to the bone Movement happens because muscles attached to bones by tendons and ligaments


Adapted from :Adapted from Pruitt, Ed.D, B.E. Prentice Hall Health. Boston, Massachusetts: Pearson Prentice Hall, 2007. Print. Bronson, Ph.D., Mary H. Glencoe Health. Minneapolis, MN: McGraw-Hill, 2007. Print.