Connective Tissues Most diverse abundant tissue Main Role

Connective Tissues Most diverse & abundant tissue

Main Role n Strength against forces n Protect organs n Maintain organ shape n Provide frame for muscle pull

2 Components n Cells + matrix ¨Cells ¨Matrix ~ ground substance n. Fibers + “Protein Glue” + Water n. Non-living

Origin of Connective. Tissue Just notice that the cells, thus tissue, thus system originates from the mesoderm, as you learned previously

Connective Tissue Cells n Fibrocyte n Chondrocyte n Osteocyte n Hematopoietic stem cell (in bone marrow) red blood cell makers

Types of Fibers n Reticular keeps cells in place n Collagen resists stretch n Elastic allows stretch

Tissues Described By : n Amount of fibers : # of cells n Arrangement of fibers in matrix n Type(s) of fiber in matrix n Ability, function or location

Types ¨Connective ¨Cartilage ¨Blood ¨Bone proper

Connective Tissue Proper (1/4) Loose few fibers : more cells

Loose & Adipose Fiber type: almost none Function: Energy storage, protection n Location ¨Under skin ¨Around organs ¨Behind eyeballs ¨Fastens kidneys

Loose & Reticular Fibers: reticular Function: scaffold for cell migration Location: lymph organs Lymph nodes bone marrow spleen

Loose & Areolar Fiber Type: Function: collagen, reticular, elastic retains water; connects epithelium to …? Location ¨Under epithelia ¨Around organs ¨Surround capillaries

Connective Tissue Proper (1/4) Dense more fibers : few cells

Dense & Regular n Description ¨Parallel direction ¨collagen & some elastic fibers ¨High stretch strength ¨Poor vascular supply Function ¨stress in one direction n Location ¨Tendons & ligaments ¨Bundle ends of muscles n

Dense & Irregular Description ¨Multi direction ¨collagen & elastic fibers ¨Resist stretch n Function ¨Withstand tension ¨structural strength n Location ¨Dermis of skin ¨digestive tract ¨joints and organs n

Dense & Elastic n Description ¨ Elastic fibers, very little collagen ¨ High elasticity n Function ¨ n Allow stretch Location ¨ Alveoli of lungs ¨ Arteries

*Cartilage 3 types n Description ¨Avascular, no nerves ¨Matrix up to 80% water n (1/4)

A. Hyaline (Glassy) Description ¨ a few collagen fibers n Function ¨Resist repetitive stress ¨Support & reinforce ¨cushion n Location ¨End of long bones ¨Costal cartilage of ribs ¨nose, trachea, & larynx n

B. Elastic Description ¨More elastic fibers ¨A Few collagen n Function ¨Maintain shape ¨Great flexibility n Location ¨external ear ¨Epiglottis n

C. Fibrous n Description ¨Thick collagen fibers n Function ¨Tensile strength ¨Absorb compression n Location ¨Intervertebral discs ¨Pubis symphysis ¨Disc of knee joint

*Blood Tissue n Description ¨Cells + fluid matrix + dissolved fibers Function ¨transport gases, nutrients, & waste n Location ¨blood vessels n (1/1)