Skeletal System

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Skeletal System

• PA 481 C
• Anatomy Physiology
• Dr. Tony Serino

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Skeletal System

• Composed of mineralized CT and their supporting
  structures including bone, cartilage, ligaments,
  tendons, and bursae
• Functions support, protection, homeostasis
  (specifically Ca regulation) and hempoiesis

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General Osteology Composition

• Cells originate from mesechyme (undifferentiated
  mesodermal cells)
• Extracellular Matrix
• Ground substances water, salts, cementing
  substances, glycoproteins
• Fibers collagen and elastin

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Cartilage

• Avascular CT
• Appositional and interstitial growth possible

Perichondrium
Chondroblast
Lacuna
Chondrocyte
Matrix
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Hyaline Cartilage
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Elastic Cartilage
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Fibrocartilage
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Cartilage in Adult
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Bone

• Heavily mineralized CT
• Highly vascular
• Principle storage area of Calcium
• Provides strength and structural support to body

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Long Bone Anatomy
Fig. 6.3
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Compact vs. Spongy Bone
Trabeculae
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Bone Histology
Fig. 6.5
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Haversian System Lamellae
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Ossification

• Development of bony tissues
• First bone to form is woven (premature) bone
• This is eventually replace by mature bone
  (compact or spongy bone)
• Two methods for creating bones
• Intramembraneous (bone replaces mesoderm
  membrane)
• Endochondral (bone replaces an intervening
  cartilage model)

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Intramembranous Ossification(membrane bone)
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Endochondral Ossification(replacement bone)
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Epiphyseal (Growth) Plate

• Reserve Cartilage (distal perichondrium)
• Proliferating Cartilage(Growth zone)
• Hypertrophic zone(Transforming zone)
• Calcified matrix(Osteogenic zone)

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Epiphyseal Plate
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Fracture Healing
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Osteoporosis
Osteoporotic
Normal
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Divisions of Skeletal System
Axial Skeleton
Fig. 7.1
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Appendicular Skeleton
Fig. 7.21
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Types of Bones
Long Bones
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Short Bones
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Flat Bones
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Irregular bones
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Sesamoid Bones
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Accessory BonesWormian (Sutural) Bones and
other supernumerary bones
Results from failure of separate ossifications
centers to fuse (common in foot and
hand) Heterotropic bones arise in soft tissue
where bones not normally present
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Articulations

• Functional Classifications
• Synarthrotic (immovable)
• Amphiarthrotic (slightly movable)
• Diarthrotic (movable)
• Structural Classification
• Fibrous held by fibrous tissue
• Cartilaginous held by cartilage
• Synovial synovial cavity within joint

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Suture (synarthrotic, fibrous joint)
Found in bones of skull
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Gomphosis (synarthrotic, fibrous)
Ligament cemented to tooth surface
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Syndesmoses (amphiarthrotic, fibrous)
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Synchondroses (Synarthrotic, cartilaginous)
Epiphyseal Plate
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Synchondroses (synarthrotic, cartilaginous)
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Symphyses (amphiarthrotic, cartilaginous)
Includes pubic symphysis
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Synovial diarthrotic joints

• The synovial membrane filters the blood to create
  synovial fluid
• This fluid lubricates and nourishes the joint
• Some joints may have an additional wedge of
  cartilage within the joint (menisci)

Fig. 8.3
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Bursae and Tendon sheaths
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Arthritis