1. The Skeletal System

2. Introduction Bones provide the body with structure and support
206 bones with joints and connective tissue
Divisions
Axial – 80 bones
Skull
Vertebral column
Rib cage
Appendicular – 126 bones
Arms and legs
Pectoral girdle
Pelvic girdle

3. The Skeletal System

4. Bone Structure Bones contain various kinds of tissues, including
Osseous tissue
Blood vessels
Nerves
Osseous tissue can appear compact or spongy

5. Bone Structure (cont.) Compact bone looks solid
Structures can be observed with a microscope
All bones are made up of both compact and spongy bone

6. Bone Structure (cont.) Classification by shape
Long bones – located primarily in the arms and legs
Femur (thigh bone)
Humerus (upper arm bone)
Short bones – small bones located in the wrists and ankles
Carpals (wrist bones)
Tarsals (ankle bones)

7. Bone Structure (cont.) Flat bones – located in the skull and rib cage
Ribs
Frontal bone
Irregular bones
Vertebrae
Bones of the pelvic girdle

8. Apply Your Knowledge Very Good! ANSWER: Match bone to classification.
___ Humerus L. Long bones
___ Rib S. Short bones
___ Femur F. Flat bones
___ Pelvic bones I. Irregular bones
___ Carpals
___ Frontal bone
___ Vertebra
___ Tarsals F L
Very Good! I S F I S

9. Functions of Bones Give shape to body parts
Support and protect soft structures
Examples – brain, lungs, heart
Allow body movement, because skeletal muscles attach to them
Allow for voluntary movement

10. Functions of Bones (cont.)
Red bone marrow of bone produces new blood cells – hematopoiesis
Store calcium

11. Correct! Apply Your Knowledge
Why is it important for the bones to store calcium?
ANSWER: Every cell in the body needs calcium, so the body must have a large supply readily available.
Correct!

12. Joints Junctions between bones Classification based on structure
Fibrous joints
Connected together with short fibers
Between cranial bones and facial bones
Sutures – fibrous joints in the skull

13. Joints Cartilaginous joints
Connected together with a disc of cartilage
Between vertebrae

14. Joints Synovial joints Covered with hyaline cartilage
Held together by a fibrous joint capsule lined with synovial membrane
Secretes synovial fluid so bones move easily against each other
Freely movable
Bones are also held together through tough, cord-like structures called ligaments

15. Apply Your Knowledge Yippee! ANSWER: A C B C A Match the following:
A. Fibrous joints B. Cartilaginous joints C. Synovial joints
____ Between cranial bones and facial bones
____ Covered with hyaline cartilage
____ Between vertebrae
____ Freely movable
____ Sutures in the skull C B
Yippee! C A

16. In Summary Skeletal system Two divisions
Bone growth through ossification
Functions
Supports the body
Protects internal organs
Attachment for muscles for movement
Stores minerals
Produces new blood cells by hematopoiesis
Joined by three types of joints