Bone and Cartilage

Slide 1 X50 Compact bone In this longitudinal section through compact bone note: Haversian canals (stained red) running parallel to the longitudinal axis of the bone The perpendicular Volkmann’s canals linking the Haversian canals to each other The lacunae in the bone matrix with fine canaliculi radiating from them What are contained in the Haversian and Volkmann canals? At what points in anatomical long bones do blood vessels enter compact bone? How do osteocytes get nourishment? Technique: Ground bone stained with acid Fuchsin. A 104

Slide 2 X100 Compact bone In this section of decalcified compact bone note: The coarse collagen fibres passing through the periosteum and inserting into the bone called Sharpey’s fibres The gray stained collagen fibres of the periosteum covering bone Blue stained compact bone The Haversian system in the bone matrix What is the function of Sharpey’s fibres? What is the function of periosteum? What type of fibre is found in bone matrix Technique: Decalcified bone stained with Iron Haematoxylin. A105

Slide 3 X100 Cancellous (Spongy) bone In this section through the internasal septum note: The trabeculae of eosinophilic cancellous bone The lamellae of bone which surround the large irregular marrow spaces The osteocytes in the lacunae in bone matrix What does trabeculum mean? What is contained in the marrow spaces? This field demonstrates a mucoperiosteum. What is a mucoperiosteum? How are the lamellae arranged in cancellous bone? How does cancellous bone differ in structure from compact bone? Technique:Haematoxylin and Eosin. CB 67

Slide 4 X400 Cartilage In this slide of external auditory meatus note: Dense irregular connective tissue forming the perichondrium (top) Lacunae in the cartilage matrix Basophilic matrix between the lacunae Oval chondroblasts at the transition of the perichondrium to cartilage matrix Rounded chondrocytes (singly or in nests) in the lacunae Abundant blue/black elastic fibres between the lacunae What is the function of perichondrium? What type(s) of growth occur(s) in cartilage? Where is the evidence of this? What do chondrocytes secrete? What similarities/differences are there between hyaline and elastic cartilage? Technique: Haematoxylin and Eosin. B101

OSTEOGENESIS In this longitudinal section of a rat embryo, note the mesenchymal cells. What is mesenchyme? What adult tissue(s) does it give rise to? What structures are seen to be arising from the mesenchyme in this field? Technique: Haematoxylin and Eosin. CB 102

Slide 6 X400 Fibrocartilage In this section of the meniscus from a knee note: The presence of chondrocytes in lacunae, arranged singly or in rows The thick eosinophilic collagen fibres around the cells? Why does fibrocartilage have such a high proportion of fibres? What collagen type are these fibres? How would you identify this tissue as cartilage? How does fibrocartilage grow? How is fibrocartilage nourished? How would you distinguish fibrocartilage from cancellous bone? Technique: Haematoxylin and Eosin. CB 79

Slide 7 X400 Cartilage In this cross section through the trachea note: The eosinophilic dense and fibrous irregular connective tissue surrounding the cartilage – called perichondrium Gradual transition from the perichondrium to the rigid cartilaginous matrix The chondrocytes which are isolated or in isogenous groups/nests The basophilic cartilaginous matrix Why does the matrix stain basophilically with H and E? What type of fibres are found in the matrix? What evidence is there of appositional/interstitial growth? How are chondrocytes nourished? What function does cartilage serve in the trachea? Technique: Haematoxylin and Eosin. A 93

Slide X400 Decalcified bone In this section of foetal skull note: Eosinophilic stained trabeculum of bone The parallel arrangement of the lamellae in the bone matrix The lacunae containing osteocytes in the matrix Single layer of cuboidal osteoblasts on the upper surface of the trabeculum 2 large multinucleated osteoclasts on the bottom of the trabeculum What is the function of osteoblasts, and how do they do this? What cell are osteoclasts derived from? What is their function in bone? Technique: Haematoxylin and Eosin. A 758

Slide 9 X100 Ground bone x3 slides In this section of ground bone note: Dark brown lumina of the Haversian canals Concentric and interstitial lamellae around and between the canals The lacunae at the borders of the lamellae with radiating weblike canaliculi Horizontal Volkmann’s canal What do Haversian canals contain? What forms the lamellae in bone? What do the lacunae contain, and what are the functions of the canaliculi? What is the function of the Volkmann’s canals? Technique: Silver Nitrate impregnation. B 53

X100 Ground bone. AGNO3 Impregnation. Haversian canals, Lamellae + canaliculi.

X400 AGNO3 Impregnation Ground Bone Haversian canal + canaliculi + Lamellae

Slide 3 x400 AGNO3 Impernation Bone with Haversian System + Volkmann’s Canal