TISSUES & CANCER

Connective Tissue

CONNECTIVE TISSUE Many functions include:

Bind structuresProvide support, protection, and frameworkFill spaceStore fatMake red blood cells (RBCs)Fight infectionRepair damage

CONNECTIVE TISSUE Not as tightly spaced as epithelial cells

Separated by extracellular matrix (ECM) Most can divide Have good blood supply Cell types:

Fixed cellsWandering cells

FIBROBLASTS Most common fixed cell Large & star-shaped Make fibers by secreting proteins into

ECM

FIBROBLASTS MAKE 3 TYPES OF FIBERS Collangenous fibers Elastic fibers Reticular fibers

COLLAGENOUS FIBERS Made up of collagen holds structures together with great

tensile strength Grouped in long, parallel bundles Found in ligaments & tendons

ELASTIC FIBERS Stretch easily Made of the protein elastin Thin fibers branch to form a complex

network Common in body parts that are

frequently stretched, like your vocal cords

RETICULAR FIBERS Very thin collagenous fibers that lend

delicate support Highly branched Found in the spleen, as well as other

tissues

MACROPHAGES A type of white blood cell Scavenger & defense cells that clean up

foreign substances from tissues through phagocytosis

https://www.youtube.com/watch?v=BDr44vLNnPY

MAST CELLS Have allergies? Thank your mast cells! Large cells near blood vessels that secrete

heparin and histamine Heparin- prevents blood clotting Histamine- dilation of blood vessels &

increased mucous productionAllergic Response!Some foods have histamine! http://

www.michiganallergy.com/food_and_histamine.shtml

LOOSE CONNECTIVE TISSUE Less packed and separated by ECM Areolar tissue, adipose tissue, and

reticular connective tissue Areolar tissue- forms delicate thin

membranes, binding skin to underlying organs

Adipose tissue- cells that store fat droplets in their cytoplasm & enlarge (insulates, cushions, & serves as energy)

DENSE CONNECTIVE TISSUE Closely packed thick collagenous fibers

and a fine network of elastic fibers Very strong Tendons and ligaments

CARTILAGE Provides support and can protect

underlying tissue Forms structural models for bones Chondrocytes are the cartilage cells Cartilage is covered in the

perichondrium, which contains the blood vessels that supply nutrients to the chondrocytes

Do not heal easily because they don’t have a direct blood supply

3 TYPES OF CARTILAGE Hyaline cartilage- ends of bones in

many joints & end of nose Important in the development and growth of

bonesLooks like white glass of fine collagenous

fibers Elastic cartilage- ears and larynx

Dense network of flexible elastic fibers Fibrocartilage- disks in the spinal column

Tough collagenous fibers that act as shock absorber

In knees too

BONE Most rigid connective tissues due to

mineral salts (Calcium phosphate) between cells

Supports body structures and protects vital organs

Contains red marrow to form blood cells Osteocytes are bone cells

BONE Form in thin layers called lamellae which

form circles around central canals = osteon

Osteons cemented together form bone

BONE Each central canal contains a blood

vessel as a nutrient supply Thus bones heal quicker than cartilage

due to the access of a blood supply

BLOOD Functions in transporting nutrients, CO2

and O2, and materials Composed of red & white blood cells

and platelets suspended in a fluid ECM called blood plasma

Red and white blood cells form in the bone marrow of long bones