BONES

1. BONES

2. Osteology= study of bones

3. Tissue: Connective • Functions: • Support • Protect soft tissue • Points of attachment for muscles • House blood producing cells • Store inorganic salts

4. 206 bones • 2 main divisions • Axial • Appendicular

5. Axial • Head, Neck, Trunk • Skull • Hyoid bone • Vertebral column • Thoracic Cage (ribs, 12 pairs) • Sternum

7. APPENDICULAR • limbs and bones connecting the limbs to the: PECTORAL GIRDLE (scapula & clavicle), UPPER LIMBS (arms)PELVIC GIRDLE (coxal bones), LOWER LIMBS (legs)

8. Bone Classification • Long bones • Short bones • Flat bones • Irregular bones * Sesamoid bones

9. 1. Long Bones- have long longitudinal axes ad expanded ends • EX: forearm, thigh bones 2. Short Bones- cube like with lengths/ widths roughly equal • Ex: wrist, ankles

10. 3. Flat Bones- platelike structures with broad surfaces Ex: Ribs, scapulae

11. 4. Irregular bones- variety of shapes, connected to several bones Ex: vertebrae, facial bones 5. Sesamoid or round bones- small and nodular Ex: kneecap

12. Long Bone • Epiphysis- expanded portion at each end of bone, articulates (forms a joint) • Diaphysis- shaft of bone • Articular cartilage- layer of hyaline cartilage • Proximal epiphysis – nearest to torso • Distal epiphysis- end furthest from torso • Periosteum- bone covered in a tough vascular covering of fibrous tissue

13. pg 194

14. Processes- bony projections for sites of attachment • Provide attachment sites, grooves/openings for passageways of blood vessels and nerves

15. 2 Bone Types • Compact bone (Cortical) - tightly packed tissue, solid, strong - Wall of diaphysis • Spongy Bone (cancellous) - many branching bone plates, covered with a layer of compact bone.

17. Medullar Cavity- hollow chamber within the diaphysis connects to spaces in spongy bone. Filled with soft specialized tissue called bone marrow. • Endosteum- thin membrane containing bone-forming cells lining medullar cavity

18. Marrow- Red Marrow - mainly in spongy bone in adults. Produces blood cells Yellow Marrow - fat storage. Replaces much of the red marrow in diaphysis through childhood

20. Microscopic Structures pg 196 • Bone Extracellular Matrix = collagen / inorganic salts • Osteocytes- located in tiny bony chambers called lacunae • Transport nutrients and waste

21. Compact Bone • Osteon- (harversian system) cylinder unit around central canal • Contain blood vessels, nerve tissue, loose CT • Central canals – extend longitudinally through bone • Perforating canal (Volkmann’s canals)- transverse canals connect central canals • Contain blood vessels and nerves

22. Spongy bone • Cells lie within trabeculae • Nutrients from subs. diffusing into the canaliculi

24. BONE DEVELOPMENT AND GROWTH

25. Two types of bones based on development • 1. INTRAMEMBRANOUS BONES = broad, flat bones of the skull. • form from membrane-like sheets of connective tissue • 2. ENDOCHONDRAL BONES =masses of cartilage that are later replaced by bone tissue • EX: long bones

26. Intramembranous Bones • Osteoblasts appear in CT • Bone forming cells • Fibers appear in matrix • Calcification occurs • Deposits of salts in matrix • Osteoblasts become osteocytes

27. Endochondral • Skeleton in cartilage • Bone replaces cartilage • Ossification centers • Areas where bone formation starts • Blood vessels penetrate cartilage

28. ALL BONES START AS HYALINE CARTILAGE, areas gradually turn to bone • PRIMARY OSSIFICATION CENTER (shaft) • SECONDARY OSSIFICATION CENTER (ends)

30. Epiphyseal disk (growth plate) is a band of cartilage b/w the epiphysis and diaphysis • These areas increase bone length as the cells ossify • Cartilage becomes osteoblasts become osteocytes

33. RESORPTION • OSTEOCLASTS - dissolve bone tissue to release minerals,  process is called RESORPTION

34. Factors Affecting Bone Growth • Absence of Calcium • Deforms bones • children= rickets • Adults= osteomalacia

35. Lack/Excess of growth hormone • Lack - Child= pituitary dwarfism • Excess- child= pituitary gigantism

36. Stress- causes bones to grow, lack of exercise causes bone tissue to waste away

37. BONE FRACTURES

38. Axial • Skull Cranium and facial bones • Hyoid bone- floats, helps with swallowing/ supports tongue • Vertebral Column • Sacrum • Coccyx • Thoracic Cage- 12 pairs of ribs and sternum

39. Appendicular • Pectoral girdle- scapula • Clavicle • Upper limbs- humerous, radius, ulna, carpals, metacarpals, phalanges • Pelvic girdle- coxa, pelvis • Lower Limbs- femur, tibia(large), fibula(slender), patella, tarsals, metatarsals, phalanges

41. 3 Basic Types of Joints (articulations):  1. SYNARTHROTIC – immoveable joint, such as bones in the skull, these junctions are called SUTURES 2. AMPHIARTHOTIC – slightly moveable joint, vertebrae 3. DIARTHROTIC – freely moveable joint, such as shoulders, hips, knees, elbows, wrists, fingers… --these joints are enclosed within a fibrous capsule which contains a lubricating fluid called SYNOVIAL fluid. These are called SYNOVIAL JOINTS.

43. Cranium Bones 1. Frontal - anterior portion above eyes 2. Parietal – one on each side of the skull, just behind frontal bone 3. Occipital – forms the back of the skull and base of the cranium 4. Temporal – forms parts of the sides and base of cranium • Sphenoid – wedged between several other bones in anterior portion of the cranium • Ethomoid – form roof of nasal cavity

44. Sutures • 1. Coronal – between frontal and parietal bones • 2. Lambdoidal – between occipital and parietal bones • 3. Squamous – between temporal and parietal bones • 4. Sagittal - between parietal bones

45. Facial Bones immovable and 1 movable jawbone • Maxillary bones • Palatine bones • Zygomatic bones • Lacrimal bones • Nasal bones • Vomer bones • Inferior nasal conchae • mandible

46. Foremens • Allow blood vessels/nerves to travel through bone • Supraorbital foremen • Infraorbital foremen • Mental foremen