cartilage and bone

Cartilage lab 7

- Hyaline cartilage ( trachea) x40.

- Elastic cartilage( ear pinna) x40.

- Fibro cartilage x40.

Hyaline cartilage

- Has homogeneous basophilic matrix. -Chondrocytes present in isogenous groups inside the

lacunae . -Its covered by perichondrium.

-Chondroblasts are beneath the Perichondrium.

Elastic cartilage -Has an abundant network of elastic fibers in addition to collagen type II.- Chondrocytes present in isogenous groups inside lacunae.-Covered by perichondrium.

Fibro cartilage- Fibro-cartilage does not have perichondrium.- The ground substance is little in amount.-The matrix contains acidophilic bundles of type I collagen fibers.- Chondrocytes present in rows in their lacunae between the collagen bundles.

Bone lab 81- Compact bone x40.

2- Cancellous bone x10.

3- Intramembranous ossification x40

4- Endochondral ossification. x 10

Compact Bone-Haversian system, consisting of bone lamellae organized concentrically around a central canal called Haversian canal.- Outer circumferential lamellae beneath the periosteum.- Inner circumferential lamellae directly under the periosteum.-Interstitial lamellae in-between the neighboring Haversian systems.- Osteocyte present in lacunae between or within the bone lamellae.

Cancellous (spongy ) bone- composed of branching and anastomosing bone trabeculae with bone marrow spaces in between them. -Haversian systems are absent in the thin trabeculae of cancellous bone.- The bone trabeculae are formed of irregularly arranged bone lamellae with osteocytes inside lacunae in between.- The bone marrow cavities are lined by endosteum.

Intramembranous ossification

-It takes place within membranous condensations of mesenchymal tissue.-In the ossification center, several bone spicules appear simultaneously and fuse together.-the bone formed has a spongy structure.

Endochondral ossificationShowing epiphyseal plate , it contains 5 zone from epiphysis to diaphysis :1. Resting zone. 2.Proliferative zone.3.Hyperatrophic zone. 4.Calcification zone.5.Ossification zone