Connective Tissue

Functions

• metabolic and structural connections between other tissues

• Protective sheath around organs

• Reserve for energy

• Framework to support the body

• Insulation for the body

• Medium for transporting substances from one region of the body to another’

Characteristics of connective tissue

Most abundant tissue by weight

• Vascularized

• 3 distinct components

• Ground substance   - medium through which cells exchange nutrients and waste in blood

• Extracellular fibers  - collagenous, reticular, elastic

• Cells    - fixed cell

ex. tendons, bloods, fat, cartilage, bone

ground substance

• medium through which cells exchange nutrients and waste with blood

• envelopes and protects delicate cells

• Effective obstacle for invading microorganisms

extracellular fibers: collagenous fibers

• strong thick strands of protein collagen

• organized into bundles

• varying density and arrangement of fibers

surrounds organs, tendons and ligaments

extracellular fibers: Reticular fibers

• thin, delicate branched networks of collagen

• provides support for highly cellular organs (endocrine glands, lymph nodes, spleen, liver, bone marrow)

• also found around nerves, blood vessels, muscle fibers, and capillaries.

extracellular fibers: elastic fibers

• composed primarily of the protein elastin

• branched to form complex networks occur in tissues subjected to stretching

(vocal chords, lungs, skin. walls of blood vessels)