Connective Tissue
-Connects body parts and is found everywhere in the body
-Most abundant of the tissue types
-Functions: protecting, supporting, binding together
-Characteristics:
-Variations in blood supply
-Well vascularized: have good blood supply
-Exceptions: tendons, ligaments, and cartilage
-Reason why they heal very slowly
-Extracellular matrix
-Non-living material that separates the living cells
-Withstands tension, bears weight, and endures trauma
-What is the Extracellular Matrix?
-Has two main elements:
1. Ground Substance: water, adhesion proteins, and
large (charged) polysaccharide molecules
-Proteins: glue to attach to connective tissue
-Polysaccharides: trap water
2. Fibers: collagen, elastic, and reticular
-Collagen: high strength
-Elastic: ability to stretch
-Reticular: form internal “skeleton” of organs
Types of Connective Tissue
1. Bone: osseous tissue
-Supports and protects softer tissue
-Most rigid of connective tissue
2. Cartilage
-Less hard and more flexible than bone
-Hyaline: larynx, attaches ribs to breast bone, cover ends
of bones where joints form
-Fibrocartilage: cushion-like discs between vertebrate
-Elastic: supports the external part of the ear
3. Dense
-Most connective tissue is dense
-Strong, rope-like structures
-Tendons: attach skeletal muscle to bone
-Ligaments: connect bones to bone joints
-Makes up lower layers of skin (dermis)
4. Loose
-Softer, have more cells and fewer fibers
-Areolar, Adipose, and Reticular
-Bone marrow, lymph, spleen
5. Blood: vascular tissue
-Blood cells surrounded by blood plasma (non-living)
-Fibers only become visible during blood clotting