Connective Tissue 1 General characteristics: _____________________________________________ Have many functions: Bind structures Provide support and protection Serve as frameworks Fill spaces Store fat Produce blood cells Protect against infections Help repair tissue damage ___________________________________________________

Extracellular Matrix There is an abundance of extracellular matrix (ECM) between the cells. *The ECM is a complex and changing mix of molecules that modifies the tissue to suit different organs and conditions. *Composed of many _____________________ and ground substance. *Serves as scaffolding to organize cells into tissues, and relays Biochemical signals that control cellular activities. ________________________________________ - consists of a variety of proteins, other molecules and fluid. Varies in consistency from fluid to semisolid to solid. *Binds, supports, and provides a medium through which substances

3 Major Cell Types 3 __________________________ Fixed cell Most common cell in C.T. Produce fibers by secreting protein into extracellular matrix ___________________________ Wandering cell Phagocytic Important in injury or infection – acts as a scavenger to clear foreign particles _____________________________ Fixed cell Release heparin - anticoagulant Release histamine – causes the itching and swelling associated with inflammation and allergies

3 Fiber Types Present 4 _________________________ Thick Composed of collagen Great tensile strength Abundant in dense CT Hold structures together Tendons, ligaments ____________________________ Bundles of microfibrils embedded in elastin Fibers branch Elastic Vocal cords, air passages __________________________________ Very thin collagenous fibers Highly branched Form supportive networks

Loose Connective Tissue 5 Loose Connective Tissue (3 kinds) 1)______________________________________ *Forms delicate, thin membranes throughout body *Fibroblast cells spread apart within a gel-like ground substance containing many collagen and elastic fibers *Binds skin to underlying tissue and fills spaces between muscles; Underlies most layers of epithelium where its many blood vessels ))

1) Areolar connective tissue

2 ) ______________________________________ Adipocytes (fat cells Stores fat; Cushions & insulate Beneath skin, behind eyeballs, around kidneys and heart

Collagenous Fibers White blood cell Fibroblast 3) _______________________________________ Composed of thin, collagenous fibers in a 3-Dimensional network Supportive framework of liver, spleen, and lymphatic organs

Dense Connective Tissue 9 Dense C.T. (3 kinds): 1) __________________________________________ many closely packed collagenous fibers & fine network of elastic fibers Few fibroblasts Very strong, able to withstand pulling forces Poor blood supply Binds body parts together as ________________________ __________________________________________________ (a

Fibroblasts Collagenous fibers Dense Regular C.T.

Collagen fibers Fibroblasts 2) __________________________________________ Collagen fibers are thicker, interwoven, and more randomly organized – allows tissue to sustain tension from many different directions Located in the ___________________________________

Collagen fibers Fibroblast Elastic fibers 3) ________________________________________ Abundant elastic fibers in parallel strands or branching networks; some collagenous fibers Fibroblasts ________________________________________________

Supporting Connective Tissue 13 A.______________________________ Rigid matrix ___________________________________ in lacunae Poor blood supply 3 types of cartilage

1) ____________________________________________ Looks like white glass, has very fine collagen fibers Most abundant type of cartilage Embryonic skeleton begins as “model” of hyaline cartilage ___________________________________________________

2) _____________________________________________ Dense network of elastic fibers Most flexible cartilage ______________________________________________

3) __________________________________________ Many collagenous fibers Very tough – shock absorber ________________________________________________

Supporting Connective Tissue B. _____________________________ Most rigid C.T. Hardness due to mineralization; Contains abundant collagenous fibers which are flexible and reinforce the bone Osteoblasts - deposit the bone matrix in concentric layers, (lamellae); Live in lacunae within the matrix Bones of Skeleton – Framework for body movement, protects, stores minerals, bone marrow makes blood cells

Fluid Connective Tissue Blood – 4 components: 1)_______________________– fluid matrix 2) ___________________________ – red blood cells Transport gases 3) ___________________________ - white blood cells Fight infection 4)___________________________ – Cell fragments Clot blood Fills the circulatory system to transport materials, fight infection, form clots

Blood – 4 Main Components

Muscle Tissue General characteristics: Muscle cells also called_______________________________ Contractile Three (3) types: Skeletal muscle Smooth muscle Cardiac muscle

Muscle Tissue 1) _______________________________________ Attached to bones Striated Voluntary

Muscle Tissue 2) ____________________________________________ Walls of organs, blood vessels Involuntary Non-striated

Muscle Tissue 3) ___________________________________________ Heart wall Involuntary Striated plus intercalated discs

Nervous Tissue Nervous tissue - found in the brain, spinal cord and peripheral nerves. A)_____________________________– highly specialized cells that sense changes and respond by transmitting nerve impulses. Coordinate, regulate and integrate body activities B) __________________________________– supportive cells

Nervous Tissue

4 Types of Membranes A.Epithelial membranes – Sheets of cells with underlying C.T. 3 types: 1) _____________________________________ – line body cavities that do not open to the outside and cover organs in these cavities (thoracic and abdominopelvic cavities). Secrete serous fluid that reduces friction. 2) _____________________________________– line body cavities that do open to the outside (oral and nasal cavities and tubes of the digestive, respiratory, urinary and reproductive systems). May contain goblet cells that secrete mucus. 3) ______________________________________ – Skin. Part of the integumentary system B. _________________________________________ – made entirely of C.T. Lines synovial joints.