Muscles of the Pectoral & Shoulder region Dr. Sama-ul-Haque Dr. Rania Jabr.
Dr. Sama ul Haque
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Transcript of Dr. Sama ul Haque
Bone and cartilage
Histology of Bone and CartilageDr. Sama ul HaqueUnderstand the histology of bone.
Understand the histology of cartilage.
ObjectivesComposition of BonesCollagen: chief organic constituent (protein)Inorganic Calcium Salts: Vitamin D essential for absorption
A Chemical Analysis of Bone
Cells Osteoblasts: bone building, bone repairing cells in the periosteum and synthesize new matrix (Osteogenesis)
Osteocytes: osteoblast embedded within the bone matrix (mature bone cells)
Osteoclasts: cells that cause absorption of bone or dissolve bone matrix (Osteolysis)
PeriosteumDense, fibrous membrane covering bone
Contains blood vessels
Essential for bone cell survival and bone formation
Endosteum
Histological or MicroscopicallyCompact bone (dense)
Basic unit of compact bone is an osteon.
Osteocytes within lacunae arranged in concentric circles called lamellae.
This surround a central canal; complex is called Haversian system.
Weight Bearing.
Histological or MicroscopicallySpongy bone (cancellous)Contains trabeculaeFound at ends of Long Bones, Ribs, Sternum, Hips, Vertebrae, CraniumWeb-Like ArrangementLow Stress Areas Where Weight of Bone Would Be a Problem.
Compact and Spongy Bone
Compact and Spongy Bone
Compact and Spongy BoneOsteoblasts and Osteocytes
Lacunae and Canaliculi Communication
Periosteum and Endosteum
Mature Bone (Compact)
Mature Bone (Spongy)
Osteon
Lacunae (L)Canaliculi (C)Osteocytes (O)
CartilageType of Dense connective tissue ( Cells and fibers)
Perichondrium ( Fibro-vasculo-cellular membrane)
Cells = Characterized by Rigid with flexibility and Resilience. Avascular
Nerves and lymphatics are absent
Cells (Chondroblasts and chondrocytes)
Matrix => Connective tissue fibers (Collagen, Elastin)
Hyaline Cartilage Hyaline (Glass) Commonest form Bluish white, translucent and homogenous in appearance with collagen fibers. Sites:=> Articular cartilage=> Costal cartilage=> Tracheal cartilage
Ossifies to form bone in young age
Hyaline Cartilage and Perichondrium
Elastic Cartilage Yellow; Elastin fibers More elastic than hyaline Sites:=> Pinna of the ear=> Epiglottis=> Auditory tube Never ossifies
Elastic CartilageFibro-cartilage White, Opaque with collagen fibers Sites=> Intervertebral disc=> Intra articular disc => Menisci Ossifies in old age
Collagen (c)
Fibrocartilage Cartilages
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