Connective Tissues. Copyright 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Transcription

1 C.T. are found in all parts of the body & diverse in structure & function. C.T. Functions: -connect structures -provide support -protect vital organs -fill space b/w structures -stores fat -defends body from infection -repairs tissue damage

2 Cells of C.T. are not packed tightly as epithelial tissue, but are separated by the matrix. The matrix consists of: - ground substance that varies from liquid to solid - 3 types of fibers: - Collagen, elastic, reticular

3 Figure 4 8 The Cells and Fibers of Connective Tissue Proper.

4 There are 4 types of C.T.: - Embryonic - C.T. proper - Solid C.T. - Fluid C.T.

5 Embryonic C.T. - One type of tissue, Mesenchyme (embryonic stem cells) are star shaped - Ground substance is gel-like w/fine protein fibers and immature cells; gives rise to all other C.T. - Location: Embryo/Fetus (not found in adults)

6 Figure 4 9 Connective Tissues in Embryos.

7 6 types of C.T. Proper: 1. Areolar C.T. - Gel-like ground substance w/collagen & elastic fibers - Cell types include fibroblasts (blast = forming), macrophages, mast cells, & white blood cells Located b/w skin & m.; b/w m., beneath epithelial layers, between adjacent organs

8 Gently pinch your skin & notice the lifted skin moves independently of the underlying m. b/c of areolar C.T. Connective Tissues

9 2. Adipose tissue - Specialized cells for fat storage Located b/w deep skin layers; walls of organs; around joints; bone cavities

10 3. Reticular C.T. - Gel-like ground substance; has network of reticular fibers with intervening reticular cells Location: wall of lymphatic organs (lymph nodes & spleen)

11 4. Dense regular C.T. - Fibroblasts arranged in parallel rows b/w densely packed bundles of collagen fibers Location: tendons, ligaments, aponeuroses (away of sinew) are layers of flat tendons

12 5. Dense irregular C.T. - Irregularly arranged collagen & elastic fibers with intervening fibroblasts Location: Dermis of skin; capsules around organs; coverings around brain, spinal cord, and nerves

13 6. Elastic Tissue - Parallel bundles of elastic fibers w/fibroblasts interspersed b/w them Location: Elastic ligaments b/w vertebrae (areas that need flexibility)

14 Two types of solid C.T.: Cartilage and bone 1. Cartilage - Chrondrocytes within cavities, called lacunae; lacunae separated by a solid matrix w/varying amounts of collagen & elastic fibers - No blood vessels: Chondrocytes produce antiangiogenesis factor - 3 types of cartilage: hyaline, elastic, & fibrocartilage

15 Supportive Connective Tissues Hyaline cartilage (hyalos = means glass) Stiff, flexible support Reduces friction between bones Found in synovial joints, rib tips, sternum, and trachea

16 Supportive Connective Tissues Elastic cartilage Supportive but bends easily Found in external ear and epiglottis

17 Supportive Connective Tissues Fibrous cartilage (fibrocartilage) Limits movement Prevents bone-to-bone contact Pads knee joints Found between pubic bones and intervertebral discs

18 The Growth of Cartilage Lacuna derived from lacus meaning hollow or lake Lacuna is a space in which a cell is located Figure 4 13 The Growth of Cartilage.

19 Bone C.T.: - Osteocytes w/in lacunae; lacunae separated by a solid matrix containing collagen fibers & calcium salts - Lamella is lamina meaning plate. Bone lamella is a layer of bone tissue Location: bones of the skeleton

20 Blood is a Fluid C.T. - Blood cells (red & white blood cells) in a fluid matrix (blood plasma) - red blood cells have no nuclei when mature, more space available to store hemoglobin - white blood cells do have nuclei