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taoyk32
17-05-09, 12:34 AM
Germ Cell Origin: Mesoderm (mesenchymal cells).

Structural Characteristics:
As its name suggests, connective tissue is the substance found between cells, and the material that helps hold different tissues together in organs.


Functions and distribution
* Connect and bind cells giving the body structural support and helping tissues resist mechanical stresses. Common examples include bone, cartilage, tendons, ligaments, and fibrous capsules encasing visceral organs.
* Functions as a physical barrier to the entry of microorganisms into the body (e.g., the dermis of the skin).
* Many connective tissue cells play a role in the defense of the body by mediating inflammation, immunity, and wound repair (macrophages, lymphocytes, fibroblasts, etc.).


Classification. There are five general categories of mature connective tissue:
o Loose connective tissue has abundant cells among few or loosely arranged fibers and a sparse to abundant gelatinous ground substance.
o Dense connective tissue has few cells among a dense network of fibers with little ground substance.
o Cartilage has cells distributed among fibers in a firm jellylike ground substance. Cartilage is tough, but flexible, avascular, and without nerves.
o Bone has cells distributed among abundant fibers in a solid ground substance containing minerals, mostly calcium phosphate. Bone is organized in units, called osteons (Haversian system). Each osteon consists of a central canal (Haversian canal), which contains blood vessels and nerves, surrounded by concentric rings (lamellae) of hard matrix and collagen fibers. Between the lamellae are cavities (lacunae) that contain bone cells (osteocytes). Canals (canaliculi) radiate from the central canal and allow nutrient and waste exchange with the osteocytes.
o Blood is composed of various blood cells and cell fragments (platelets) distributed in a fluid matrix called blood plasma.

Các bạn xem phần sửa lại của thầy nhé, còn đây là hình minh họa cho BONE, hơi khó hình dung thật:
http://www.web-books.com/eLibrary/Medicine/Physiology/Skeletal/compact_spongy_bone.jpg

Các bạn đọc cho ý kiến nhé.
Xem thêm hình minh họa:
http://medinfo.ufl.edu/pa/chuck/summer/handouts/connect.htm
http://www.cliffsnotes.com/WileyCDA/CliffsReviewTopic/Connective-Tissue.topicArticleId-22032,articleId-21890.html