Cartilage

StructureNo nerves or blood vesselsSurrounded by perichondriumMatrixLacunaeChondrocyte

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