HUMAN SKELETON AN ENDOSKELETON

CARTILAGE HYALINE ELASTIC FIBROCARTILAGE

STRUCTURE OF CARTILAGE MATRIX CHONDROCYTES/ CHONDROBLASTS PERICHONDRIUM

MATRIX

CHONDROBLASTS

CHONDROCYTES

INTERSTITIAL VS APPOSITIONAL GROWTH

TYPES OF CARTILAGE HYALINE CARTILAGE ELASTIC CARTILAGE FIBROCARTILAGE

HYALINE CARTILAGE COVERS ARTICULAR SURFACES CARTILAGINOUS PORTION OF NOSE COSTAL CARTILAGE

HYALINE CARTILAGE MOST COMMON TYPE OF CARTILAGE CLOSELY PACKED COLLAGEN FIBERS TRANSLUCENT COSTAL CARTILAGES TRACHEAL CARTILAGES ARTICULAR CARTILAGES

ELASTIC CARTILAGE PINNA OF EAR EUSTACHIAN TUBES GLOTTIS CUNEIFORM CARTILAGES OF LARYNX

FIBROCARTILAGE LITTLE GROUND SUBSTANCE PREDOMINANTLY COLLAGEN FIBERS INTERVERTEBRAL DISCS SYMPHYSIS PUBIS MENISCI OF KNEE

FUNCTIONS OF THE SKELETON SUPPORT MOVEMENT PROTECTION MINERAL RESERVE HEMATOPOIESIS FAT STORAGE

BONE CLASSIFICATION LONG BONES SHORT BONES FLAT BONES IRREGULAR BONES SESAMOID BONES

LONG BONES HUMERUS RADIUS ULNA FEMUR TIBIA FIBULA PHALANGES

SHORT BONES CARPALS TARSALS SESAMOID BONES

SHORT BONES EMBEDDED IN TENDONS PATELLA

FLAT BONES CALVARIUM RIBS STERNUM

IRREGULAR BONES ETHMOID SPHENOID VERTEBRAE SCAPULA PELVIC BONES

LONG BONE STRUCTURE DIAPHYSIS EPIPHYSES MEDULLARY CAVITY ENDOSTEUM PERISOTEUM

PERIOSTEUM

SHARPEY’S FIBERS

ENDOSTEUM

YELLOW BONE MARROW

RED BONE MARROW

SPONGY BONE

COMPACT BONE

STRUCTURE OF COMPACT BONE

EPIPHYSEAL LINE

EPIPHYSEAL PLATE

FLAT BONE STRUCTURE

HISTOLOGY OF BONE

BONE MATRIX 35 PERCENT ORGANIC COLLAGEN PROTEOGLYCANS 65 PERCENT INORGANIC HYDROXYAPATITE

TYPES OF BONE CELLS OSTEOBLASTS OSTEOCYTES OSTEOCLASTS

OSTEOBLASTS EXTENSIVE ENDOPLASMIC RETICULUM LOTS OF RIBOSOMES PRODUCE COLLAGEN AND PROTEOGLYCANS PRODUCE HYDROXYAPATITE PRECURSORS

FUNCTION OF OSTEOBLASTS OSSIFICATION OR OSTEOGENESIS

OSTEOCYTES FORMED WHEN OSTEOBLASTS ARE SURROUNDED BY MATRIX MAINTAIN MATRIX AROUND THEMSELVES LACUNAE CANLICULI

OSTEOCLASTS

LARGE CELLS MULTINUCLEATE RUFFLED BORDER PUMP HYDROGEN IONS AND ENZYMES INTO MATRIX

RESORPTION OF BONE OSTEOCLAST PRIMARILY RESPONSIBLE OSTEOBLAST ASSIST

WHERE DO BONE CELLS COME FROM MESENCHYMAL CELLS STEM CELLS OSTEOGENIC/OSTEO PROGENITOR CELLS OSTEOCLASTS HAVE A DIFFERENT ORIGIN

ORGANIZATION OF BONY TISSUE WOVEN VS LAMELLAR CANCELLOUS VS COMPACT

CANCELLOUS BONE INTERCONNECTING RODS OR PLATES TRABECULAE SPONGY BONE

COMPACT BONE DENSER FEWER SPACES OSTEONS CENTRAL CANAL PERFORATING CANALS

HOW DOES BONE DEVELOP INTRAMEMBRANOUS VS ENDOCHONDRAL OSSIFICATION

INTRAMEMBRANOUS OSSIFICATION

MESENCHYMAL MEMBRANE FORMATION BEGINS ABOUT 5TH WEEK GESTATION

OSSIFICATION BEGINS AT ABOUT 8TH WEEK GESTATION

IS COMPLETED BY ABOUT TWO YEARS OF AGE

BONES FORMED BY INTRAMEMBRANOUS OSSIFICATION SKULL BONES MANDIBLE PARTS OF CLAVICLES

RED BONE MARROW

ENDOCHONDRAL OSSIFICATION

CARTILAGE FORMATION BEGINS AT ABOUT THE FOURTH WEEK OF GESTATION

OSSIFICATION BEGINS AT ABOUT 8 WEEKS OF GESTATION

SOME MAY NOT BEGIN OSSIFICATION UNTIL LATER

BONES FORMED BY ENDOCHONDRAL OSSIFICATION FEMUR HUMERUS ETC

BONE GROWTH APPOSITIONAL GROWTH

ROLE OF THE EPIPHYSEAL PLATE IN BONE GROWTH ZONE OF RESTING CARTILAGE ZONE OF PROLIFERATION ZONE OF HYPERTROPHY ZONE OF DIFFERENTIATION

ZONE OF RESTING CARTILAGE

ZONE OF PROLIFERATION

ZONE OF HYPERTROPHY

ZONE OF DIFFERENTIATION

HOW THE ARTICULAR CARTILAGE GROWS SIMILAR TO PROCESS IN EPIPHYSEAL PLATE COLUMNS ARE NOT AS PRONOUNCED

HOW BONES INCREASE IN DIAMETER APPOSITIONAL GROWTH

FACTORS THAT AFFECT BONE GROWTH NUTRITION HORMONES

NUTRITION VITAMIN D VITAMIN C

VITAMIN D NECESSARY FOR ABSORPTION OF CALCIUM SYNTHESIZED BY BODY OR INGESTED LACK CAN CAUSE RICKETS OR OSTEOMALACIA

VITAMIN C NEEDED FOR COLLAGEN SYNTHESIS

HORMONES GROWTH HORMONE THYROID HORMONE ESTROGENS ANDROGENS

GROWTH HORMONE INCREASE TISSUE GROWTH INCREASE BONE GROWTH STIMULATES INTERSTITIAL CARTILAGE GROWTH STIMULATES BONE GROWTH

THYROID HORMONE STIMULATES NORMAL CARTILAGE GROWTH

ESTROGENS STIMULATE GROWTH CAUSES RAPID GROWTH AT EPIPHYSEAL PLATE CAUSE QUICKER CLOSURE OF EPIPHYSEAL PLATE THIS IS WHY FEMALES ARE GENERALLY SMALLER THAN MALES

TESTOSTERONE STIMULATES BONE GROWTH SLOWER TO CLOSE EPIPHYSEAL PLATE THAT IS WHY MALES ARE GENERALLY TALLER

BONE REMODELING REMOVAL OF OLD BONE BY OSTEOCLASTS DEPOSITION OF NEW BONE BY OSTEOBLASTS

FUNCTIONS OF REMODELING CONVERTS WOVEN BONE INTO LAMELLAR BONE BONE GROWTH CHANGES IN BONE SHAPE ADJUSTMENTS TO STRESS BONE REPAIR CALCIUM ION REGULATION

CALCIUM HOMEOSTASIS PARATHYROID HORMONE CALCITONIN

PARATHYROID HORMONE MAJOR REGULATOR OF BLOOD CALCIUM LEVELS DIRECT EFFECT ON OSTEOBLASTS INDIRECT EFFECT ON OSTEOCLASTS INCREASES UPTAKE OF CALCIUM BY GI TRACT PROMOTES FORMATION OF VITAMIN D BY KIDNEYS INCREASES REABSORPTION OF CALCIUM BY KIDNEYS

CALCITONIN DECREASES OSTEOCLAST ACTIVITY INCREASES CALCIUM STORAGE

BONE FRACTURES AND REPAIR

TYPES OF FRACTURES

SIMPLE

COMPOUND

COMMINUTED

DEPRESSED FRACTURE

IMPACTED

SPIRAL

GREENSTICK

COLLE’S FRACTURE

POTTS FRACTURE

COMPRESSION FRACTURE

Repair of a Fracture (1) Formation of fracture hematoma –damaged blood vessels produce clot in 6-8 hours, bone cells die –inflammation brings in phagocytic cells for clean-up duty –new capillaries grow into damaged area Formation of fibrocartilagenous callus formation –fibroblasts invade the procallus & lay down collagen fibers –chondroblasts produce fibrocartilage to span the broken ends of the bone

Repair of a Fracture (2) Formation of bony callus –osteoblasts secrete spongy bone that joins 2 broken ends of bone –lasts 3-4 months Bone remodeling –compact bone replaces the spongy in the bony callus –surface is remodeled back to normal shape

BONE REPAIR HEMATOMA FORMATION INTERNAL CALLUS FORMATION EXTERNAL CALLUS FORMATION CARTILAGE OSSIFICATION BONE REMODELING

HEMATOMA

CALLOUS FORMATION

CARTILAGINOUS CALLUS

CONVERSION TO BONY CALLUS

BONE REMODELING

IMPORTANCE OF STRESS IN BONE REPAIR

EFFECTS OF AGING ON THE SKELETAL SYSTEM LOSS OF CALCIUM FROM BONE MORE SEVERE IN WOMEN THAN MEN PROTEIN SYNTHESIS MAY SLOW LEADING TO BRITTLE BONES