Skeleton system types of bones in human system
- 1. SKELETON SYSTEM DR. DEEPANSHU SHUKLA -Assistant Professor
- 2. LEARNING OBJECTIVES= 1. Introduction 2. Divisions of the skeletal system 3. Definition and composition of bones 4. Functions of bones 5. Classification of bones 6. Gross structure of an adult long bone 7. Parts of a young growing bone 8. Blood supply of bones 9. Nerve supply of bones 10.Development and ossification of bones
- 3. INTRODUCTION • Skeleton is composed of bones and cartilages. • Skeleton forms the main supportive framework of the body. • Designed for a more effective production of movements by the attached muscles. • It provides protection to viscera.
- 5. Divisions Of The Skeletal System
- 6. BONES OF AXIAL SKELETON AXIAL SKELETON Cranial Bones 8 Facial Bones 14 Hyoid Bone 1 Ear ossicles (3 in each ear) 6 Vertebral Bones 26 Sternum 1 Ribs 24 Total 80
- 7. BONES OF APPENDICULAR SKELETON APPENDICULAR SKELETON Clavicle 2 Scapula 2 Humerus 2 Ulna 2 Radius 2 Carpals 16 Metacarpals 10 Phalanges 28 Hip Bone 2 Femur 2 Fibula 2 Tibia 2 Petella 2 Tarsals 14 Metatarsals 10 Phalanges 28 Total 12 6
- 8. Definition of Bone • Synonyms- 1. Os (L), 2. Osteon (G). • Bones are the hard structures, which forms the rigid framework of the body. • Bone is a highly vascular mineralized connective tissue. • Composed of organic and inorganic materials. • The inorganic salt calcium hydroxy apatite is removed by putting the bone in acid, it becomes flexible and can be tied as a “knot”. • If organic tissue is removed by burning, the bone crumples into small pieces.
- 9. FUNCTIONS OF BONES • Provide shape and support of the body. • Provide surface for the attachment of muscles, tendons, ligaments. • Serve as levers for muscles to bring about a movement. • Protect certain viscera, e.g. brain, spinal cord, heart, lungs, liver, bladder, etc. • Contain marrow which is factory of blood cells, e.g. W.B.Cs, R.B.Cs and platelets. • Store 97% of the body calcium and phosphorus.
- 11. Microscopic Structure Of Bones
- 12. Microscopic Structure Of Bones
- 13. Microscopic Structure Of Bones
- 15. (A) According to Shape 1. Long Bones 2. Short Bones 3. Flat Bones 4. Irregular Bones 5. Pneumatic Bones 6. Sesamoid bones 7. Accessory ( supernumerary ) Bones
- 16. 1. LONG BONES
- 20. 2. SHORT BONES
- 22. 3. FLAT BONES
- 25. 5.* PNEUMATIC BONES *
- 27. 6.* SESAMOID BONES *
- 32. WORMIAN BONE
- 33. OS TRIGONUM
- 34. OS VESALIANUM
- 35. PATELLA CUBITI
- 36. (B) Developmental Classification 1. Membranous Bones- membranous ossification. eg.- bones of cranial vault, Facial bones. 2. Cartilagenous Bones- endochondral ossification. eg.- ribs, sternum, vertebrae, bones of limbs. 3. Membrano-cartilaginous Bones- by both membranous and endochondral ossification. eg.- mandible, clavicle, occipital bone, temporal bone, sphenoid bone.
- 37. (C) Regional Classification 1. Axial Skeleton 2. Appendicular Skeleton
- 38. (D) Structural Classification Macroscopically : 1. Compact Bone 2. Cancellous ( Spongy/Trabecular ) Bone Microscopically : 3. Lamellar bone 4. Woven bone 5. Fibrous bone 6. Dentine 7. Cement
- 39. MACROSCOPICALLY
- 40. COMPACT BONE The texture of compact bone is dense, ivory- like with no visible spaces on naked eye examination. The compact bone consists of: a) Lamellae of collagenous sheets, b) Haversian system or osteons.
- 41. COMPACT BONE
- 42. COMPACT BONE
- 43. COMPACT BONE
- 44. HAVERSIAN SYSTEM ( OSTEON)
- 45. HAVERSIAN SYSTEM ( OSTEON) •Each haversian system consists of a haversian canal ( or central canal), surrounded by concentric lamellae of bone. •Haversian canal are lined by endosteum. •Haversian canals communicate with each other, with the medullary cavity and with the surface of bone by numerous Volkmann’s canal. •The volkmann’s canal run perpendicular to the long axis of the bone. •The blood vessels from the periosteum or endosteum enter the bone through Volkmann’s canal.
- 46. HAVERSIAN SYSTEM ( OSTEON)
- 49. MICROSCOPICALLY
- 51. WOVEN BONE
- 52. DENTINE & CEMENT
- 53. GROSS STRUCTURE OF AN ADULT LONG BONE 1. Shaft (diphysis) 2. Two ends (epiphysis): • Upper end • Lower end
- 54. Shaft: •It is elongated part between the two expanded ends. •It is made of an outer thick shell of compact bone enclosing a cavity called medullary cavity. Ends: •The ends are knobby (expanded) and largely made up of cancellous bone covered by a thin shell of a compact bone. •The ends of long bone are covered by an articular hyline cartilage and take part in the formation of joints.
- 56. PERIOSTEUM & ENDOSTEUM •The outer surfaces of all the bones are covered by a thick fibrous membrane called periosteum, •Whereas their inner surfaces are lined by a thin fibrous membrane called endosteum. •Both periosteum and endosteum contain osteoprogenitor cells, osteoblasts and osteoclasts which are essential for formation, remodeling and repair of bone. •The periosteum is a thick fibrous membrane covering the entire surface of bone except at the areas covered by an articular cartilage. •At the articular margin, the periosteum is continous with the joint capsule.
- 57. FUNCTIONS OF PERIOSTEUM • Protects and maintains the shape of the bone. • Provides attachment to ligaments, tendon, muscles and intermuscular septa. • Provides regenerative capability to the bone.
- 58. PARTS OF A YOUNG GROWING BONE 1. Epiphysis 2. Diaphysis 3. Metaphysis 4. Epiphysial plate of cartilage
- 59. EPIPHYSIS Types of Epiphysis: a. Pressure epiphysis b. Traction epiphysis c. Atavistic epiphysis d. Aberrant epiphysis
- 62. EPIPHYSEAL PLATE
- 64. METAPHYSIS
- 65. BLOOD SUPPLY OF BONES Arterial supply Young Long Bones a. Nutrient artery b. Periosteal arteries c. Epiphysial arteries d. Metaphyseal arteries
- 66. BLOOD SUPPLY OF BONES
- 67. BLOOD SUPPLY OF BONES
- 69. DEVELOPMENT AND OSSIFICATION OF BONES • All the bones develop from a mesenchyme (mesodermal embryonic tissue) by a process called ossification. Types Of Ossification=
- 70. • Flat bones of skull, viz. frontal, parietal, occipital, clavicle, etc. are ossified by intramembranous ossification. • All the long bones of limbs are ossified by intracartilagenous ossification.
- 76. OSSIFICATION (GROWTH) OF A LONG BONE
- 80. Growing End Of The Long Bone
- 82. • Write short notes on 1. Ossification. 2. Pneumatic bone. 3. Cartilage. 4. Epiphysis. 5. Sesamoid bone. 6. Haversian system or osteon QUESTIONS