1. The Skeletal System

9. Skeletal System Introduction Introduction Functions of the skeleton Functions of the skeleton Framework of bones Framework of bones The skeleton through life The skeleton through life

10. Functions of the Skeleton Support Support Framework for attachment of soft tissues Framework for attachment of soft tissues Protection Protection Delicate structures, especially flat bones Delicate structures, especially flat bones Movement Movement Storage areas Storage areas Minerals Minerals Lipids Lipids Hemopoiesis - blood cell production Hemopoiesis - blood cell production Red marrow Red marrow

11. Anatomy of a Long Bone Diaphysis - shaft Diaphysis - shaft Epiphysis – extremity of bone Epiphysis – extremity of bone Articular cartilage – covers epiphysis Articular cartilage – covers epiphysis Periosteum – covering around surface of bone Periosteum – covering around surface of bone Medullary cavity – marrow cavity in diaphysis Medullary cavity – marrow cavity in diaphysis Endosteum – lines medullary cavity Endosteum – lines medullary cavity

12. Anatomy of a Long Bone

13. The Periosteum

14. The Endosteum

15. Structure of Tissue Pores Pores Living cells Living cells Channels for blood vessels Channels for blood vessels Decrease weight of bone Decrease weight of bone Degree of porosity Degree of porosity Spongy bone Spongy bone Compact bone Compact bone

16. Internal Structure of a Long Bone

17. Compact Bone Haversian system Haversian system Location Location Outer surfaces of all bones Outer surfaces of all bones Most tissue of long bones Most tissue of long bones Function Function Support Support Protection Protection Movement Movement

18. Spongy bone Contains large spaces filled with red marrow Contains large spaces filled with red marrow Location Location Most tissue of short, flat, irregular bones Most tissue of short, flat, irregular bones Epiphyses of long bones Epiphyses of long bones Function Function Storage area for red marrow Storage area for red marrow Hemopoiesis Hemopoiesis

19. Microscopic Structure of Spongy Bone

20. Bone Development and Growth

21. Ossification Embryo skeleton Embryo skeleton Begins as cartilage & membrane Begins as cartilage & membrane 2 types 2 types Intramembranous ossification Intramembranous ossification Endochondral ossification Endochondral ossification

22. Intramembranous Ossification Mostly in flat bones Mostly in flat bones Connective tissue cells in membranes become osteoblasts Connective tissue cells in membranes become osteoblasts Begin to deposit bone matrix Begin to deposit bone matrix Matrix becomes mineralized Matrix becomes mineralized Formation of spongy bone Formation of spongy bone Original layer of connective tissue remains as periosteum Original layer of connective tissue remains as periosteum

23. Intramembranous Ossification

26. Endochondral Ossification Occurs within a hyaline cartilage model Occurs within a hyaline cartilage model Occurs in most bones of the body Occurs in most bones of the body Periosteum forms at about week 8 Periosteum forms at about week 8 Calcification begins in center of diaphysis Calcification begins in center of diaphysis Primary ossification center Primary ossification center Secondary ossification centers at epiphyses Secondary ossification centers at epiphyses Medullary cavity forms Medullary cavity forms

27. Endochondral Ossification

29. Fetus. 10 weeks

30. Fetus, 16 weeks

31. Remaining Cartilage Articular cartilage Articular cartilage Epiphyseal plate Epiphyseal plate Bone grows in length Bone grows in length

32. Epiphyseal Plates and Lines

33. Homeostasis Remodeling Remodeling Different rates in body Different rates in body Balance between osteoclasts and osteoblasts Balance between osteoclasts and osteoblasts Factors affecting bone growth Factors affecting bone growth Calcium & phosphorus in diet Calcium & phosphorus in diet Osteoporosis Osteoporosis Vitamins A, C, & D Vitamins A, C, & D Hormones Hormones Growth hormone – stimulates bone growth Growth hormone – stimulates bone growth Sex hormones – stimulate osteoblasts Sex hormones – stimulate osteoblasts

34. Organization of the Skeletal System Axial skeleton Skull Vertebral column Thoracic cage Appendicular skeleton Pectoral girdle Upper limbs Pelvic girdle Lower limbs

35. The Human Skeleton

36. Skull Cranium Cranium Protects brain Protects brain Facial bones Facial bones Protect sense organs Protect sense organs

37. Vertebral Column Vertebrae Vertebrae Separated by intervertebral discs Separated by intervertebral discs 4 regions 4 regions Cervical Cervical Thoracic Thoracic Lumbar Lumbar Sacral Sacral Sacrum Sacrum Several fused vertebrae Several fused vertebrae Coccyx Coccyx Rudimentary tailbone Rudimentary tailbone Function Function Protect spinal cord and nerves Protect spinal cord and nerves

38. The Vertebral Column

39. Intervertebral Discs

40. The Atlas and Axis

41. A Typical Vertebra

42. The Sacrum and Coccyx

43. Thoracic Cage Ribs (12 pairs) Ribs (12 pairs) Articulate with vertebrae Articulate with vertebrae Sternum (breastbone) Sternum (breastbone) Function Function Protect underlying organs Protect underlying organs

44. The Thoracic Cage

46. Pectoral Girdle Scapula (shoulder blade) Scapula (shoulder blade) Clavicle (collar bone) Clavicle (collar bone) Attached to posterior ribs and sternum Attached to posterior ribs and sternum Function Function Connects bones of arms to axial skeleton Connects bones of arms to axial skeleton Aids in arm movements Aids in arm movements

47. The Pectoral Girdle

48. Upper Limbs Humerus Humerus Radius Radius Ulna Ulna Carpals Carpals Metacarpals Metacarpals Phalanges Phalanges

49. The Pectoral Girdle and Upper Limb

50. The Radius and Ulna

51. Bones of the Wrist and Hand

52. Pelvic Girdle Coxal (hip) bones Coxal (hip) bones Ileum Ileum Ischium Ischium Pubis Pubis Attached to sacrum and coccyx Attached to sacrum and coccyx Function Function Connect bones of legs to axial skeleton Connect bones of legs to axial skeleton

53. The Pelvic Girdle

55. Lower Limbs Femur Femur Tibia Tibia Fibula Fibula Patella Patella Tarsals Tarsals Metatarsals Metatarsals Phalanges Phalanges

56. The Pelvic Girdle and Lower Limb

57. The Femur

58. Bones of the Lower Leg

59. The Patella

60. Bones of the Foot