Histology_(6)__Skeletal_Connecti_tissue.pptx

Histology

1. Skeletal (supportive) Connective Tissues Skeletal connective tissues Cartilages bones Cartilages: Cartilage is a tough, flexible form of connective tissue, characterized by Jelly-like matrix (chondroitin sulfate) containing collagen and elastic fibers. Collagen fibers make the tissue strong and chondroitin sulfate makes it resilient Poor in blood supply and nerves It provides support, frameworks, attachments, serves as template for developing bones Cartilage is enclosed by a dense CT called Perichondrium , except in articular surfaces of the joints. Cartilage cells: Condrogenic ( perichondrial cell), chondroblast and chondrocyte. there are 3 types of cartilages; hyaline, elastic and fibrocartilage

2. Hyaline cartilage Hyaline (Gr. hyalos , glassy) cartilage, the most common of the three forms, is homogeneous and semi-transparent in the fresh state Found in the respiratory tract, ribs, end of long bones, and skeleton of the Embryos and in the latyx . Cartilage cell(chondrocyte) is located in Lacunae-holes in the matrix in which the cells sit ( 2,4,8 ) Weakest of the 3 types of cartilage

3. Elastic cartilage Elastic cartilage is essentially similar to hyaline cartilage except that it contains an abundant network of elastic fibers in addition to collagen type II, which give fresh elastic cartilage a yellowish color. Elastic cartilage is found in the auricle of the ear, the walls of the external auditory canals, the eustachian tubes, and in the epiglottis.

4. Fibrocartilage Fibrocartilage takes various forms but is essentially a combination of hyaline cartilage and dense connective tissue with gradual transitions between these tissues Chondrocytes of fibrocartilage occur singly among visible bundles of collagen fibers and in small lacunae aligned in rows. No perichondrium Fibrocartilage provides very tough , strong support at tendon insertions and in intervertebral discs and certain other joints. Strongest of the 3 types of cartilage

5. Bone Tissue (osseous tissue) Bone is a specialized connective tissue composed of calcified extracellular material, the bone matrix, and bone cells Most rigid type f connective tissues Mineral salts between cells Supports, protects body structures Houses marrow (where blood cells form) serves as a reservoir of calcium, phosphate, and other ions that can be released or stored in a controlled fashion to maintain constant concentrations in body fluids. External and internal surfaces of bone are covered by tissue layers with bone-forming cells, called periosteum and endosteum, respectively.

6. Types of the bone: according to their structure: primary (woven) or secondary (lamellar) b) according to their architecture bone are either: Spongy or compact All bone tissues begins as primary(woven) bone, and then replaced by secondary(lamellar) Shape of the bone : long, short, flat, or irregular bone

7. There are 2 types of the bone: – compact bone and spongy bone Compact bone : Osteon – basic unit of compact bone Lamellae – concentric circles of matrix Lacunae – spaces in the matrix that house cells Osteocytes – mature bone cells

8. Spongy bone: Trabeculae – columns of bone with spaces filled with red bone marrow