CONNECTIVE TISSUE (C.T.) The excitement is building!  ** Connects! ** MOST ABUNDANT TISSUE TYPE IN BODY! 1

Binds together body tissues FUNCTIONS OF C.T. Protects organs Supports organs Binds together body tissues 3

Characteristics of C.T. 1) VARY IN BLOOD SUPPLY Most are vascularized (have a blood supply) Some exceptions: Tendons, ligaments, and cartilage are avascular (heal very slowly when injured!) 4

Characteristics of C.T. continued 2) Have an extracellular matrix (ECM) – which is a collection of molecules found outside of the cells that provide structural support to the surrounding cells Matrix can be liquid, semisolid, or solid depending on tissue type and enables C.T. to withstand weight and stretching 5

Collagen Fibers: Large fibers of the connective tissue (C.T.) matrix made of the protein collagen and are typically the most abundant fibers; promote tissue flexibility

Fibroblasts: Secrete fibers and ground substance of the matrix of C.T.

Mast cells: Cells that release histamine and other substances during inflammatory and allergic reactions Mast cell – Allergies visual video clip

Macrophages: white blood cells that engulf and digest cellular debris and foreign substances in a process called phagocytosis

Elastic fibers: Branching fibers of the C.T. matrix made of the protein elastin; allow for stretch and recoil

Blood vessels/blood cells: Arteries, veins, and capillaries transport oxygen and carbon dioxide; red blood cells transport oxygen & white blood cells are immune system cells

Adipocytes: Fat cells that store energy as fat (lipids); this fat insulates the body

Fill-in CONNECTIVE TISSUE CHART

1) LOOSE C.T. (AREOLAR) DESCRIPTION: Areola means small open space – most of the matrix of this tissue appears to be empty space FUNCTION: Wraps and cushions organs; holds internal organs together – acts as “glue” LOCATION: Around organs 15

2) ADIPOSE DESCRIPTION: FAT cells FUNCTION: is reserve “fuel” or energy, protects organ by cushioning them, and functions in insulation LOCATION: Found around organs, under skin, within abdomen, in breasts

3) DENSE C.T. DESCRIPTION: Collagen fibers in matrix give tissue flexibility, fibroblasts are cells that make the fibers FUNCTION: tendons connect muscle to bone and ligaments connect bone to bone; they withstand stress when pulled LOCATION: tendons, ligaments

4) HYALINE CARTILAGE DESCRIPTION: Hyaline cartilage is the most abundant type of cartilage; (elastic cartilage is found in ear and nose) - One cell is called a chondrocyte FUNCTION: supports and reinforces organs LOCATION: looks glass-like and covers ends of bones at joints and in ribs

5) BONE DESCRIPTION: Bone cells called osteocytes are in cavities called LACUNAE One large circle (unit of bone) is an OSTEON FUNCTION: Osseous tissue has a very strong and hard matrix that protects internal organs and supports the body; provides levers for the muscles to act on LOCATION: bones

6) BLOOD DESCRIPTION: Contains blood cells! Red blood cells appear pink on the slide and white blood cells are purple The fluid matrix is called blood plasma FUNCTION: transport for the circulatory system carrying nutrients and wastes LOCATION: Throughout the entire body