14 poonam bones

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14 poonam bones

  1. 1. BONE CAPT DR POONAM SINGH
  2. 2. BONE 1. 2. 3. 4. 5. 6. 7. 8. INTRODUCTION FUNCTIONS CLASSIFICATIONS PARTS OF GROWING LONG BONE BLOOD SUPPLY OF A LONG BONE HISTOLOGY DEVELOPMENT APPLIED
  3. 3. INTRODUCTION • Specialized CT with a solid matrix which is mineralized & adapted for giving strength, support & helping in wt transmission. • Inorganic material ( calcium phosphate, traces of other salts..) provides hardness & rigidity to the bone radiopaque in XR.
  4. 4. FUNCTION 1. Shape & support ( forms framework) 2. Protection 3. Movement 4. Storage 5. Blood cell formation 6. PNS:- Resonance to voice
  5. 5. REGIONAL CLASSIFICATION Axial skeleton (80)  Skull & facial bones  Vertebral column  Thoracic cage Appendicular skeleton (126)  Upper limb: Girdle & free bones  Lower limb: Girdle & free bones  206 number is not exact; varies
  6. 6. DEVELOPMENTAL CLASSIFICATION 1) Membranous bones • Ossify in membrane • Derived from mesenchymal condensation Bones of skull vault & facial bones 2) Cartilaginous bones • Ossify from cartilage • Derived from preformed cartilage models Bones of limbs & vertebral column 3) Membrano-cartilaginous bones • Dev by both
  7. 7. STRUCTURAL CLASSIFICATION (MACROSCOPICALLY) 1. COMPACT BONE:- Hard & dense , resembles ivory - No visible spaces. • Consists of :- Lamellae of collagenous sheets - Haversian system / Osteons
  8. 8. COMPACT BONE Lamellae :- 3 types 1. Concentric: surrounds Haversian canal 2. Interstitial: lie between osteons 3. Circumferential: flat plates extend around the bone
  9. 9. STRUCTURAL CLASSIFICATION (MACROSCOPICALLY) 2. CANCELLOUS BONE:- Sponge work of trabeculae, trabeculae are oriented along lines of stress. - Large spaces filled with red bone marrow. - Osteoblasts +nt on their surfaces.
  10. 10. STRUCTURAL CLASSIFICATION (MICROSCOPICALLY) 1). Woven bone - Warp & weft of a woven fabric. - Eg.. Young fetal bones Callus at # sites 2). Lamellar bone - mineralized matrix arrange in thin layers. - 2 diff patterns a) concentric cylindrical units. Eg. Compact bone b) branching & anastomosing curved plates. Eg. Spongy bone
  11. 11. MORPHOLOGICAL CLASSIFICATION 1. 2. 3. 4. 5. 6. 7. Long bones Short bones Flat bones Irregular bones Pneumatic bones Sesamoid bones Accessory bones
  12. 12. LONG BONES - Length exceeds the breadth & thickness. - confined to limbs - one elongated shaft & 2 expanded ends - Shaft has medullary cavity, typically has 3 borders & 3 surfaces - Ossify in cartilage: 1 primary and 2 secondary ossification centre - Are weight bearing - May be – Typical- Humerus – Miniature- One epiphysis (Metatarsals) – Modified- No medullary cavity (Clavicle)
  13. 13. SHORT BONES • Cubical or modified cubes • Have generally 6 surfaces; 4/ less are articular, & 2/ more for attachments of ligaments & for blood vessels to enter • Develop in cartilage • Begin to ossify after birth – Eg..Carpals & tarsals
  14. 14. Flat bones • Resemble sandwiches • Consists of two layers of compact bone & marrow spread between them • Form boundaries of certain bony cavities – Eg..Bones of skull vault, Scapula
  15. 15. IRREGULAR BONE • Irregular or mixed shape • Composed of spongy bone & marrow in compact covering bone – Eg..Vertebrae, Hip bone
  16. 16. PNEUMATIC BONE • Irregular bones which contain air spaces lined with mucous membrane • Typically in skull bones • Make the skull light • Impart resonance to voice • Act as conditioning chambers for inspired air – Eg..Maxilla, Ethmoid
  17. 17. SESAMOID BONES -Develop in some tendons -Periosteum absent -Rubbing surface is covered with articular cartilage -Appear after birth usually by multiple centers -Lacks haversian systems. Functions 1) Minimize friction 2) Alter direction of pull of muscle 3) Act as pulleys for muscle contraction Eg….Patella, Pisiform
  18. 18. ACCESSORY BONES • Generally not +nt in our body • s/t clinicians confuse with fractures • Formed due to non fusion of epiphysis • Appearance of extra ossification centers in skull
  19. 19. GENERAL STRUCTURE 1. Outer surface: Periosteum ( dense fibrous CT) -Tendons & ligaments attach to bone & become continuous with fibers of periosteum. - Sharpy’s fibers: some collagen fibers of tendons or ligaments penetrate the periosteum and into the bone. Strengthen attachment of tendon or ligaments to bone. 2. Bony cavities: Endosteum (thin CT) Bone marrow ( red & yellow) More cellular
  20. 20. PARTS OF GROWING LONG BONE • 2 ends & a shaft. • Before ossification:1). Epiphysis - types 2). Epiphyseal plate 3). Metaphysis 4). Diaphysis
  21. 21. BLOOD SUPPLY OF LONG BONE 1. Nutrient / Medullary Artery • Main artery of shaft 3 4 • Enters at nutrient foramen; runs obliquely thru cortex • Divides into ascending & descending branches in medullary cavity • Each subdivides into small parallel channels terminating in metaphysis • Supplies: Medullary cavity, Inner 2/3 cortex & Metaphysis 1 2
  22. 22. BLOOD SUPPLY OF LONG BONE 2. Periosteal arteries: • Enter at many points , numerous, ramify beneath the Periosteum • Enter the bone thru Volkmann's canal • Supply: Outer 1/3rd cortex 3. Epiphyseal arteries: From periarticular vascular arcade 4. Metaphyseal arteries: derived from neighboring arteries & enter the metaphysis directly along the attachment of jt capsule
  23. 23. MICROSCOPIC STRUCTURE OF BONE • Cells + Matrix ( ground substance + fibers) Fibers:- Type I collagen fibers -mechanical strength & elasticity Ground substance:1) 1/3 Organic:- Proteoglycans, glycoprotein,.. 2) 2/3 inorganic:- Hydroxyapatite CaPO4 crystals IN MATURE BONE 10-20%= Water 60-70%= Inorganic mineral salts 30% = Collagen Remainder= Non-collagenous protein & carbohydrates
  24. 24. BONE CELLS • CELLS:- 5 Types 1. Osteoprogenitor cells 2. Osteoblasts 3. Osteocytes 4. Bone lining cells 5. Osteoclasts
  25. 25. OSTEOPROGENITOR CELLS • Derived from mesenchymal stem cells. • Osteoblasts precursor cells. • Flattened , elongated ovoid nuclei. • Transcription factor CBFA1 ( RUNTX2) • Location:- Periosteum, endosteum, stromal component of BM.
  26. 26. OSTEOBLAST • Differentiated bone- forming cell that secretes bone matrix. • Shape:- Cuboidal / polygonal. • Nucleus:- eccentric • fxns: 1.Synthesize & secrete osteoid 2. Mineralization of matrix
  27. 27. OSTEOCYTES • Mature bone cell enclosed by bone matrix. • Oval, 25µ in long axis • Prominent nucleus • Cell lacunae Processes Canaliculi • Fxn:- 1)Maintains bone tissue. 2)Mechanotransduction. 3)Calcium homeostasis
  28. 28. BONE LINING CELLS • Inactive Osteoblasts. • Flattened • 2 types:-Periosteal cells -Endosteal cells
  29. 29. OSTEOCLASTS • Large , multinucleated cells found at sites where bone is being removed. • Cells lie in pit:Resorption bay (Howship’s lacunae). • Helps in resorption of bone and remodeling.
  30. 30. OSTEON
  31. 31. Bone Ground Section T.S
  32. 32. Bone Ground Section L.S
  33. 33. Compact Bone TS (H&E)
  34. 34. Spongy Bone/ Trabecular Bone
  35. 35. Bone Development • All the bones develop from a mesenchyme. • Two types of ossification:1) Intramembranous -Takes place in connective tissue membrane. 2) Intracartilaginous/ Endochondral -Takes place in cartilage.
  36. 36. INTRAMEMBRANOUS OSSIFICATION • Takes place in CT membrane formed from embryonic mesenchyme • Skull bones, Part of mandible, Diaphyses of clavicles • Centers of ossification: appear in membrane where ossification begins (centers of ossification expand outwards to form a bone by gradually ossifying the membrane) • Fontanels: large membrane-covered spaces between developing skull bones; unossified (bones eventually grow together & all fontanels have closed by 2 years of age)
  37. 37. INTRACARTILAGINOUS OSSIFICATION • Cartilage formation begins at end of 4th wk of development. • Some ossification begins at about 8th wk; some does not begin until 18-20 years of age. • Bones of the base of the skull, Part of the mandible, Epiphyses of the clavicles, Remaining bones of skeletal system.
  38. 38. INTRACARTILAGINOUS OSSIFICATION
  39. 39. Zones of the Epiphyseal Plate
  40. 40. Growth in Bone Length
  41. 41. FRACTURE OF BONE 1. Simple / closed # 2. Compound / open # T/t :- realigning the broken ends & then immobilizing them until # is healed.
  42. 42. REPAIR OF FRACTURE
  43. 43. RICKETS • Softening of bones in immature mammals • Frequent chilhood disease in many developing countries • Cause:1). deficiency or impaired metabolism of vitD, phosphorous or Ca++ fractures and deformity. 2). severe diarrhea and vomiting may be the cause of the deficiency 3). severe malnutrition
  44. 44. OSTEOMALACIA • softening of the bones caused by defective bone mineralization. • Cause:- inadequate amounts of available phosphorus and calcium - overactive resorption of calcium from the bone as a result of hyperparathyroidism. - vitamin D deficiency • Signs:- diffuse body pains muscle weakness fragility of the bones
  45. 45. OSTEOMYELITIS • infection and inflammation of the bone or bone marrow. OSTEOPOROSIS • Bone mineral density(BMD) is reduced • bone micro architecture deteriorates • the amount and variety of proteins in bone are altered. • Fractures are the most dangerous aspect of osteoporosis.
  46. 46. OSTEOPHYTE (bone spur) -commonly referred to as bone spurs or parrot beak -bony projections that form along joint margins Sites:1) Back of the spine. 2) Feet either along toes or heel. 3) Hands. Osteophytes on the fingers & toes :Heberden’s node,if +nt on the distal interphalangeal joint & Bouchard’s node, if +nt on the proximal IP jt.
  47. 47. POSHITIS • Poshitis is a concept conceived in 2013 describing a Girl that Carry a heavy handbag and get sick of it. • The name is derived from Victoria Beckham's use of heavy handbag's.
  48. 48. THANK YOU

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