1. Skeletal System
Chapter 5

2. cranium
mandible
sternum
humerus
carpals
metacarpals

3. Functions of the Bone Support Protection Movement Storage
Form the internal framework for the body
Protection
Protect soft body organs
Example – Ribs and skull
Movement
Skeletal muscles, attach to skeleton by tendons, use the bones to move the body
Storage
Fat and calcium is stored in bones
Blood cell formation
Occurs in bone marrow

4. Classification of Bones
Adult skeleton has 206 bones.
Compact bone – dense and looks smooth and homogenous
Spongy bone – Composed of small needlelike pieces of bone and lots of open spaces

5. Classification of Bones (cont.)
Four different shapes of bone
Long bones – longer than they are wide

6. Classification of Bones (cont.)
Short bones – cube-shaped and contain mostly spongy bone

7. Classification of Bones (cont.)
Flat bones – thin, flattened, and usually curved

9. Classification of Bones (cont.)
Irregular bones – bones that don’t fit one of the preceding categories

10. Classification of Bones (cont.)
Skeleton system is divided into two categories
Axial skeleton – bones that form the longitudinal axis of the body
Cranium and vertebral column
Appendicular skeleton – bones of the limbs

11. Structure of a Long Bone
Diaphysis – shaft of bone
Made of compact bone
Periosteum – covers the
diaphysis
Epiphysis – the ends of the
long bone
Filled with spongy bone
Articular cartilage – covers the
external surface of the
epiphysis

12. Structure of a Long Bone (cont.)
Epiphyseal plate – cause
the lengthwise growth
of the long bone
Epiphyseal line – replaces
the epiphyseal plate after
puberty

13. Structure of a Long Bone (cont.)
Yellow marrow stores
adipose tissue
Found in the diaphysis
Made of compact bone
Red marrow produces
blood
Found in the epiphysis
Made of spongy bone

14. Bone Fractures Simple or closed Compound or open Bone breaks clearly
but does not penetrate
the skin
Compound or open
Broken ends of the bone
protrude through soft
tissues and the skin

15. Simple Fracture or Compound Fracture?

16. Bone Fractures (cont.) Comminuted Bone breaks into many fragments
Common in geriatrics with brittle bones

17. Bone Fractures (cont.)
Compression
Bone is crushed

18. Bone Fractures (cont.) Depression
Broken bone portion is pressed inward
Common fracture in skull

19. Bone Fractures (cont.) Impacted
Broken bone ends are forced into each other

20. Bone Fractures (cont.) Spiral Excessive twisting forces bone to break
Common sports fracture

21. Bone Fractures (cont.) Greenstick
Bone breaks incompletely, much in the way a green twig breaks
Common in children

22. Repairing Bone Fractures
Week 1
Blood vessels are
ruptured when bone
breaks.
Hematoma is formed
Blood-filled swelling

23. Repairing Bone Fractures (cont.)
Weeks 2-3
New blood vessels
form.
Hematoma hardens
forming fibrocartilage
callus (or soft callus).
Fibrocartilage callus
(made of some bone
and cartilage) forms
over the break.

24. Repairing Bone Fractures (cont.)
Weeks 4-16
The fibrocartilage
callus ossifies
(or hardens)
becoming spongy
bone.
This forms a bony
callus (or hard callus).

25. Repairing Bone Fractures (cont.)
Weeks 17 and more
Bony callus is
remodeled so that it
forms a “patch” over
the break.
The “fixed” part of the
bone will be the
strongest part.

26. Infant Skull Fontanel – soft spot
Skull is cartilaginous and hardens as an infant ages
As an individual grows, fontanels fuse to form sutures

27. Vertebral Column Cervical – neck Thoracic – chest Lumbar – lower back
7 vertebrae
C1 – C7
Thoracic – chest
12 vertebrae
T1 – T12
Lumbar – lower back
5 vertebrate
L1 – L5
Sacrum
5 fused vertebrae
Coccyx – tail bone
4 fused vertebrae

28. Vertebral Column Atlas – C1 Axis – C2 Supports weight of the skull
allows the head to turn

29. Vertebral Column Spinal problems
Bulging disk - extends outside the space it should normally occupy
Herniated disk - results when a disk ruptures