1. Structure, Function, and Diseases
The Skeletal System:
Structure, Function, and Diseases
of the bones and joints

2. Is this the correct anatomical position?

3. The Skeletal System Parts of the skeletal system
Bones (skeleton)
Joints
Cartilages
Ligaments (bone to bone)(tendon=bone to muscle)
Divided into two divisions
Axial skeleton- skull, spinal column
Appendicular skeleton – limbs and girdle
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4. Functions of Bones Support of the body Protection of soft organs
Movement due to attached skeletal muscles
Storage of minerals and fats
Blood cell formation
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5. Bones of the Human Body The skeleton has 206 bones
Two basic types of bone tissue
Compact bone
Homogeneous
Spongy bone
Small needle-like pieces of bone
Many open spaces
Figure 5.2b
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6. Bones are classified by their shape:
Long- bones are longer than they are wide (femur, humerus)
Short- usually square in shape, cube like (carpals, tarsals)
Flat- flat, curved (skull, sternum, ribs)
Irregular- odd shapes (vertebrae, pelvis)

7. Classification of Bones on the Basis of Shape
Figure 5.1
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8. Classification of Bones
Long bones
Typically longer than wide
Have a shaft with heads at both ends
Contain mostly compact bone
Examples: Femur, humerus
Slide 5.4a
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9. Classification of Bones
Short bones
Generally cube-shape
Contain mostly spongy bone
Examples: Carpals, tarsals
Slide 5.4b
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10. Classification of Bones
Flat bones
Thin and flattened
Usually curved
Thin layers of compact bone around a layer of spongy bone
Examples: Skull, ribs, sternum
Slide 5.5a
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11. Classification of Bones
Irregular bones
Irregular shape
Do not fit into other bone classification categories
Example: Vertebrae and hip
Slide 5.5b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

12. Gross Anatomy of a Long Bone
Diaphysis
Shaft
Made of compact bone
Epiphysis
Expanded ends of long bones
Covered with dense bone
Internal structure is spongy bone
Figure 5.2a
Slide 5.6
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13. Structures of a Long Bone
Periosteum
Outside covering of the diaphysis
Fibrous connective tissue membrane
Arteries
Supply bone cells with nutrients
Figure 5.2c
Slide 5.7
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14. Structures of a Long Bone
Articular cartilage
Covers surface of epiphyses
Hyaline cartilage
Decreases friction at joint surfaces
Figure 5.2a
Slide 5.8a
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15. Types of Bone Cells Osteocytes Osteoblasts Osteoclasts
Mature bone cells
Osteoblasts
Bone-forming cells
Osteoclasts
Bone-destroying cells
Break down bone matrix for remodeling and release of calcium
Bone remodeling is a process by both osteoblasts and osteoclasts
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16. Changes in the Human Skeleton
In embryos, the skeleton is primarily hyaline cartilage
During development, much of this cartilage is replaced by bone
Cartilage remains in isolated areas
Bridge of the nose
Parts of ribs
Joints
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17. Long Bone Formation and Growth
Figure 5.4a
Slide 5.14a
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18. Repair of Bone Fractures
Hematoma (blood clot) is formed
Break is splinted by fibrocartilage
forms a callus (chondroblasts, other cells, and vessels)
Callus is replaced by a bone (osteoblasts)
Bony callus is remodeled (osteoclasts)
Slide 5.18
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19. Repair of Bone Fractures
Fracture Repair
Hematoma formation (A)
Callus formation (B)
Bone replacement (C )
Bone remodeling (D) A B C D
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20. Axial skeleton supports and protects organs of head, neck and trunk
skull (cranium and facial bones)
hyoid bone (anchors tongue and muscles associated with swallowing)
vertebral column (vertebrae and disks)
bony thorax (ribs and sternum)

21. Appendicular skeleton includes bones of limbs and bones that anchor them to the axial skeleton
shoulder girdle (clavicle, scapula)
upper limbs (arms)
pelvic girdle (sacrum, coccyx)
lower limbs (legs)
Articulation- where joints meet, connect, and are formed.

24. The Axial Skeleton Forms the longitudinal part of the body
Divided into three parts
Skull
Vertebral Column
Rib Cage
Slide 5.20a
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25. The Axial Skeleton Slide 5.20b Figure 5.6
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26. The Skull 8 sutured bones in cranium
Facial bones: 13 sutured bones 1 mandible
Cranium
encases brain
attachments for muscles
sinuses

28. Bones of the Skull Figure 5.11
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29. Allows for
growth

30. The Vertebral Column
Vertebrae separated by intervertebral discs made of cartilage
The spine has a normal S curvature
Each vertebrae is given a name according to its location
Figure 5.14
Slide 5.28
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32. Thoracic cage
ribs
thoracic Vertebrae
sternum
costal cartilages
True ribs are directly attached to the sternum
(first seven pairs)
Three false ribs are joined to the 7th rib
Two pairs of floating ribs

34. Joints
A joint, or articulation, is the place where two bones come together.
Fibrous- Immovable:connect bones, no movement. (skull and pelvis).
Cartilaginous- slightly movable, bones are attached by cartilage, a little movement (spine or ribs).
Synovial- freely movable, much more movement than cartilaginous joints. Cavities between bones are filled with synovial fluid. This fluid helps lubricate and protect the bones.

35. The Synovial Joint Slide 5.51 Figure 5.28
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36. Types of Synovial Joints Based on Shape
Figure 5.29a–c
Slide 5.52a
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37. Types of Synovial Joints Based on Shape
Figure 5.29d–f
Slide 5.52b
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38. Types of synovial joints
In ball and socket joints, the rounded end of one bone fits inside a cup-shaped ending on another bone.
Ball and socket joints allow movement in all directions and also rotation. The most mobile joints in the body are ball and socket joints.
Examples: Shoulders and hips.
Hip
Describe ball and socket joints at the hip and shoulder. Discuss the movements possible at these joints. How do they help during sport?

39. Types of synovial joints
Pivot joints have a ring of bone that fits over a bone protrusion, around which it can rotate.
These joints only allow rotation.
Atlas
Examples: The joint between the atlas and axis in the neck which allows you to shake your head.
Axis

40. Types of synovial joints
In saddle joints, the ends of the two bones fit together in a special way, allowing movement forwards and backwards and left to right, but not rotation.
Examples: The thumb is the only one.
Hinge joints – as their name suggests – only allow forwards and backwards movement.
Examples: The knee and elbow.
Elbow

41. Types of Joints
Hinge- 
A hinge joint allows extension and retraction of an appendage. (Elbow, Knee)

42. Ball and Socket- 
A ball and socket joint allows for radial movement in almost any direction. They are found in the hips and shoulders. (Hip, Shoulder)

43. Gliding- In a gliding or plane joint bones slide past each other
Gliding- 
In a gliding or plane joint bones slide past each other. Mid-carpal and mid-tarsal joints are gliding joints. (Hands, Feet)

44. Saddle- This type of joint occurs when the touching surfaces of two bones have both concave and convex regions with the shapes of the two bones complementing one other and allowing a wide range of movement. (Thumb)