1. The Skeletal System

2. The Human Skeleton Made up of 206 bones
Bones come in many different forms
Many parts of the body are made up of several bones joined together i.e. Each hand is made up of 27 bones
Skeletal is hard and durable
Bones are composed primarily of calcium
Bones are able to repair themselves (with the help of casts, splints, pins, etc.)

3. Role of the Skeleton Provides structural support for the body
Protects vital organs i.e. Rib cage protects the lungs and heart
Red blood cells and platelets are produced in the marrow of bones
Bones serve as a reservoir to regulate calcium and other minerals
Works in conjunction with the muscular system to cause movement
*Table 2.1 – page 10

4. The Structure of the Skeleton
Divided into two main parts
Axial skeleton
Appendicular skeleton
Appendicular-->
Axial-->

5. The Axial Skeleton 80 bones
Made up of the vertebral column (spine), the skull, and the rib cage
Vertebrae protect the spinal cord
The skull/cranium protects the brain
Ribs protect the lungs and heart
7 “true” pairs
3 “false” pairs
2 “floating” pairs

6. The Appendicular Skeleton
126 bones
Includes movable limbs and supporting structures
Upper limbs are attached to the shoulder girdle
Two scapulae and two clavicles
The humerus attaches to move the arms
Lower limbs are attached to the pelvic girdle
Two hip bones and the sacrum
The femur attaches to move the legs

7. Types of Bones 1. Long bones – found in the arms and legs
2. Short bones – most common in the wrists and ankles
3. Flat bones – are flat and thin, often protect vital organs from injury
4. Irregular bones – odd-looking bones such the vertebrae
5. Sesamoid bones – small, flat bones wrapped within tendons that move over bony surfaces i.e. The patella

8. Types of Bones
Flat
Short
Sesamoid
Irregular
Long

9. Anatomy of a Long Bone
Articulating cartilage: located on both ends of the bone. Allows for smooth movement within joints
Periosteum: outer connective tissue, covers entire length of bone. Does not unite with articulating cartilage.
Medullary cavity: found inside the shaft of the bone. Filled with red (blood-cell formation) and yellow (adipose tissue) bone marrow.

10. Continued...
Compact bone: more dense part of the bone. Responsible for the bone's structural integrity
Diaphysis: shaft of the bone
Cancellous/spongy bone: filled with marrow
Epiphysis: the very ends of a long bone.