Q: What did the skeleton say while riding his Harley Davidson motorcycle?

1. Q: What did the skeleton say while riding his Harley Davidson motorcycle? A: I'm bone to be wild! Q: What do you call a cold skeleton? A: A numb-skull!

2. Functions of Bones Support -pillars & cradles soft organs Protection -skull, vertebrae, rib cage Movement -attachment for muscles Storage -Ca2+, P3-; fat in bone marrow Hematopoiesis -blood cell formation in marrow cavities

3. Classification of Bones • AXIAL SKELETON • SKULL • VERTEBRAL COLUMN • RIB CAGE • APPENDICULAR SKELETON • UPPER LIMBS • LOWER LIMBS • SHOULDER BONES • HIP BONES

4. Classification of Bones • Compact • Dense • Looks smooth • homogeneous • Spongy • Open spaces • Small needle like pieces

5. Classification of Bones Shape • long bones • short bones • flat bones • irregular bones 5

6. Long Bones • longer than • wide • shaft • compact bone • ends • spongy bone • bones of • limbs & digits

7. Short Bones • cube-like • spongy bone • with compact • shell • bones of • wrist and • ankle

8. Flat Bones • thin, flattened • slightly curved • spongy bone • between • compact bone • sternum, • cranial bones

9. Irregular Bones • odd-shaped • spongy bone • surrounded by • compact bone • vertebra, hip • bones

10. Structure of Long Bone • Long bones consist of a diaphysis and an epiphysis • Diaphysis • Tubular shaft that forms the axis of long bones • Composed of compact bone that surrounds the medullary cavity • Yellow bone marrow (fat) is contained in the medullary cavity

12. Structure of Long Bone • Epiphyses • Ends of long bones • Exterior is compact bone, and the interior is spongy bone • Joint surface is covered with articular (hyaline) cartilage • Epiphyseal line separates the diaphysis from the epiphyses • Remnant of epiphyseal plate seen in young growing bones before puberty.

13. Bone Membranes • Periosteum – double-layered protective membrane • Outer fibrous layer is dense regular connective tissue • Inner osteogenic layer is composed of osteoblasts and osteoclasts • Richly supplied with nerve fibers, blood, and lymphatic vessels, which enter the bone via nutrient foramina • Secured to underlying bone by Sharpey’s (perforating) fibers • Endosteum – delicate membrane covering internal surfaces of bone

14. Structure of Short, Irregular, and Flat Bones • Thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone (diploë) on the inside • Have no diaphysis or epiphyses • Contain bone marrow between the trabeculae

15. Structure of a Flat Bone Figure 6.4

16. Location of Hematopoietic Tissue (Red Marrow) • In infants • Found in the medullary cavity and all areas of spongy bone • In adults • Found in the diploë of flat bones, and the head of the femur and humerus

17. Microscopic Structure of Bone: Compact Bone • Haversian system, or osteon – the structural unit of compact bone • Lamella – weight-bearing, column-like matrix tubes composed mainly of collagen • Haversian, or central canal – central channel containing blood vessels and nerves • Volkmann’s canals – channels lying at right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal

19. Microscopic Structure of Bone: Compact Bone • Lacunae – small cavities in bone that contain osteocytes • Canaliculi – hairlike canals that connect lacunae to each other and the central canal

20. Chemical Composition of Bone: Organic • Osteoblasts – bone-forming cells • Osteocytes – mature bone cells • Osteoclasts – large cells that resorb or break down bone matrix • Osteoid – unmineralized bone matrix composed of proteoglycans, glycoproteins, and collagen

21. Bone Remodeling Cycle

22. Osteoporosis

23. Chemical Composition of Bone: Inorganic • Mineral salts • Sixty-five percent of bone by mass • Mainly calcium phosphates • Responsible for bone hardness and its resistance to compression

24. Bone Markings • Bulges, depressions, and holes that serve as: • Sites of attachment for muscles, ligaments, and tendons • Joint surfaces • Conduits for blood vessels and nerves

25. The Axial Skeleton • Eighty bones segregated into three regions • Skull • Vertebral column • Bony thorax

26. The Skull • The skull, the body’s most complex bony structure, is formed by the cranium and facial bones • Cranium – protects the brain and is the site of attachment for head and neck muscles • Facial bones • Supply the framework of the face, the sense organs, and the teeth • Provide openings for the passage of air and food • Anchor the facial muscles of expression

27. Anatomy of the Cranium • Eight cranial bones – two parietal, two temporal, frontal, occipital, sphenoid, and ethmoid • Cranial bones are thin and remarkably strong for their weight

28. Skull: Anterior View

29. Skull: Posterior View

30. Skull: Lateral View Figure 7.3a

31. Frontal (1) glabella frontal sinuses Parietal (2) Occipital (1) foramen magnum occipital condyles external occipital protuberance Temporal (2) zygomatic process mandibular fossa external acoustic meatus styloid process mastoid process carotid canal Sphenoid (1) optic canal sella turcica Ethmoid (1) crista galli nasal concha Maxilla (2) alveolar margin infraorbital foramen Palantine (2) Zygomatic (2) Lacrimal (2) lacrimal fossa Nasal (2) Inferior nasal concha (2) Vomer (1) Mandible (1) mandibular notch ramus coronoid process alveolar margin mental foramen Cranial & Facial Bones & Markings • Hyoid bone • Paranasal sinuses • Sutures

43. Bones and Cartilages of the Human Body Figure 6.1

44. Skeletal Cartilages All bones begin as cartilage or fibrous connective tissue membranes Basic structure • mostly water (resiliency) • avascular, no nerves • surrounded by perichondrium • chondrocytes in matrix

45. Hyaline cartilage • fine collagen fibers • flexibility and resilience • bone ends, costal, nasal, etc Elastic cartilage • elastic fibers • ear, epiglottis Fibrocartilage • thick collagen fibers--pressure • vertebral discs, menisci

46. Cartilage Growth Appositional • new cells under perichondrium • increase thickness Interstitial • chondrocytes divide, new matrix • increases length

47. Human Anat-Phys Oct. 2010

50. Adolescence--growth stops With aging cartilage calcifies • normal to certain extent • not bone