Cartilage Structure No nerves or blood vessels Surrounded by perichondrium Matrix Lacunae Chondrocyte

Cartilage Hyaline Support with flexibility & strength Most abundant Very fine collage fibers Articular cartilage Costal cartilage Respiratory cartilage/nasal cartilage Larynx

Cartilage Elastic Lots of elastic fibers Withstand repeated bending External ear Epiglottis

Cartilage Fibrocartilage Compressible Tensile strength Alternating rows of chondrocytes and collagen Meniscus Intervertebral disc Pubic Symphysis

Cartilage Growth of cartilage –Appositional growth –Interstitial growth

Skeletal System Divisions –Axial –Appendicular

Skeletal System Bone shapes –Long bones –Short bones –Flat bones –Irregular bones

Skeletal System Functions of bone –Support –Protection –Allow movement –Mineral storage –Hematopoiesis –Detoxification

Skeletal System Structure of a long bone –Diaphysis –Medullary cavity –Epiphysis

Skeletal System Structure of a long bone –Periosteum –Endosteum –Compact bone –Spongy bone –Nutrient foramen

Skeletal System Microscopic anatomy/Compact bone –Haversian system Lamella Haversian canal Volkmann’s canals Lacunae Osteocytes Canaliculi

Skeletal System Microscopic anatomy/Compact bone –Interstitial lamellae –Circumferential lamellae

Skeletal System Microscopic anatomy/Spongy bone –Trabeculae –Irregularly arranged lamellae –Osteocytes –Canaliculi –No osteons

Skeletal System Chemical Composition of Bone –Organic Osteoblasts Osteocytes Osteoclasts Osteoid –Proteoglycans –Glycoproteins –Collagen fibers –Sacrificial bonds

Skeletal System Chemical Composition of Bone –Inorganic compounds Hydroxyapatites –Calcium phosphates

Skeletal System Bone development –Intramembraneous ossification Ossification center appears in the fibrous connective tissue membrane Bone matrix (osteoid) is secreted within the fibrous matrix

Skeletal System Bone development –Intramembraneous ossification Woven bone and periosteum form Bone collar of compact bone forms and red marrow appears

Skeletal System Bone development –Endochondrial ossification Bony collar forms around the diaphysis of the hyaline cartilage model. Cartilage in the center of the diaphysis calcifies and cavitates

Skeletal System Bone development –Endochondrial ossification Periosteal bud invaded the internal cavities and spongy bone forms The diaphysis elongates and medullary cavity forms

Skeletal System Bone development –Endochondrial ossification The epiphysis ossify. Secondary ossification centers form.

Skeletal System Growth in Length –Growth zone –Transformation zone –Osteogenic zone

Skeletal System Growth in Width –Appositional growth –Osteoblasts beneath the periosteum secrete matrix. –Osteoclasts on endosteal surface remove bone. –Less breakdown than secretion.

Skeletal System Hormone Control –Growth hormones –Sex hormones

Skeletal System Remodeling –Bone deposition Osteoblasts Vitamin C, D, and A Ca, P, Mg, and Mn Alkaline phosphatase

Skeletal System Remodeling –Bone resorption Osteoclasts Resorption bays Ruffled border –Lysosomal enzymes –Hydrochloric acid

Skeletal System Remodeling –Hormonal control PTH –Stimulates osctoclasts –Calcium is released into blood stream Calcitonin –Inhibits bone resorptin –Encourages calcium deposition

Skeletal System Remodeling –Mechanical stress Wolff’s Law – Long bones are thickest midway along diaphysis – Curved bones are thickest where the are most likely to buckle – Trabeculae of spongy bone form struts along lines of compression. – Large, bony projections occur where heavy muscles attach.

Skeletal System Fracture Repair –Classification of fractures Position of ends – Displaced – Nondisplaced Degree of break – Complete – Incomplete

Skeletal System Fracture Repair –Classification of fractures Orientation of break – Linear – Transverse Soft tissue damage – Open – Closed

Skeletal System Fracture Repair –Healing process Hematoma formation Fibrocartilage callus forms Bony callus forms Bone remodeling

Skeletal System Disorders –Osteomalacia –Rickets –Osteoporosis –Paget’s disease