1. Orthopedics

2. Skeletal System Structures
Bone
Cartilage
Tendons and ligaments
Joints
What are the functions of the skeletal system?

3. Bone Tissue Specialized connective tissue Forms Cells-osteocytes
Bone forming and bone destroying
Matrix surrounding cells
Calcium salts and collagen for strength

4. Types of Bone Cortical (compact)-outer layer
Haversian system-circular rings of bone matrix
Canals with single venule and arteriole
Lacuna-spaces housing a single osteocyte
Volkman’s canal-canaliculi through which the filamental projections of the osteocyte extend
Cancellous (spongy)-inner layer
Composed of osteocytes and matrix
Trabeculae-bony matrix columns providing structure and strength in long columns

5. Periosteum Thin fibrous layer of connective tissue surrounding bone
2 cell layers
Cambium-inner
Forms new bone cells
Outer layer is protective
Infection
Collagen fibers anchor to bone and merge with tendons and ligaments
Nerves and blood vessels of periosteum supply underlying bone
Endosteum lines the marrow cavity

6. Bone Marrow Semi-solid tissue found in the spaces of cancellous bone
Red marrow
Infants to young adults
Ends of long bone, sternum, ribs, vertebrae
Produces-RBC, WBC, platelets
Yellow marrow
Slowly replaces red marrow in adulthood
Does not produce RBC
Reverts to red marrow in hemorrhagic trauma

7. Types of Bones Long Bones Which Bones are long bones? Segments
Diaphysis
Epiphyses
Articular cartilage, synovial fluid, and synovial membrane allow smooth motion
Bursa-sacks containing synovial fluid-cushion impact
Epiphyseal plate-active bone growth-endochondral ossification. Closes

8. Types of Bones (cont) Short bones (D) Flat bones (B) Occur in clusters
Aid in movement of an exctremity
Flat bones (B)

9. Types of Bones (cont) Irregular bones (C) Sesamoid (round) bones
Found within tendons

10. Types of Joints Articulation-area where 2 bones meet
Classified according to movement
Immovable-synarthrosis
Slightly Movable-amphiarthrosis
Disk of fibrous cartilage lies between bones
Freely moveable-diarthrosis (synovial joints)
All have a synovial membrane that secretes synovial fluid

11. Types of Freely Movable Joints
Ball and socket-rotational
Ball head articulates with a cup socket
Condyloid-moves in one plane only (some lateral movement)
Condyle fits into a fossa
Flex/extend, adduct/abduct/circumduct
Does not rotate

12. Types of Freely Movable Joints
Hinge-movement in only one plane
Flex/extend only
Pivot-rotation around a single axis
One bone rotated around the other.
Saddle Joint-movement in a variety of planes
Surfaces of both bones have a concave and convex surface

14. Joint Movement Terms Abduction Adduction Circumduction Rotation
Dorsiflexion
Plantar flexion
Eversion
Inversion
Flexion
Extension
Pronation
Supination

15. Bone Growth and Bone Cells

16. Intramembranous Bones
Cranial and facial bones
Start as fibrous connective tissue
Some of these cells (fibroblasts) become osteoblasts (later become osteocytes)
Osteoblasts form bone matrix-ossification
Deposit calcium salts-cancellous bone
Cells outside developing bone form periosteum
Cells inside periosteum form compact bone over the cancellous bone
Continues after birth-suture lines of cranium (fontanels)
Ossify by age 2

17. Endochondral Bone Most bones of the embryonic skeleton
Made of Cartilage
Osteoblasts generate bone matrix in the center of diaphyses (primary ossification center)-progress outward
Epiphyseal disk forms at junction of epiphyses and diaphyses
Cartilage is produced and bone grows in length
Ends at age 16 to 25
Osteoclasts breakdown and reabsorb bone allowing reshaping
During embryonic development osteoclasts reabsorb bone in center of diaphysis forming medullary canal
Later fills in with red bone marrow

18. Mineral Storage Bone stores calcium Other minerals
Necessary for many bodily functions
Calcium is removed from bones to blood stream
Parathyroid hormone stimulates osteoclasts to break down bone and release calcium
Calcitonin is released by the thyroid gland to inhibit osteoclast action
Osteoblast are stimulated to reform new bone
Balance between osteoblasts and osteoclasts keeps bone strong
Other minerals
Phosphorus, magnesium, sodium, potassium

19. Factors Affecting Bone Growth
Hormones
Heredity
Potential for height
Nutrition
Raw materials for bone formation from food
Vitamin D required to absorb calcium and phosphorus
Calcium, phosphorus and protein become part of bone matrix
Exercise
Weight-bearing and stress
Without it bones loose calcium faster than it is replaced
Walking is sufficient to maintain bone

20. Clinical Terms Ankylosis Arthralgia Arthrocentesis Arthrodesis
Arthroplasty
Arthroscopy
Colles’ fracture
Laminectomy
Osteochondritis
Osteogenesis
Osteogenisis imperfecta
Osteoma
Osteomalacia
Osteomyelitis
Osteomecrosis
Osteoporosis
Osteotomy
Synovectomy

21. Anatomical Landmarks and Terms for Bone
Appendicular skeleton
Axial skeleton
Condyle
Crest
Distal
Epicondyle
Foramen
Fossa
Fovea
Head
Process
Proximal
Trochanter
Tubercle
Tuberosity