connective tissue(most abundant tissue in body by weight)

areolar(aka loose connective tissue)

-"loose connective tissue" -mainly fibroblasts -elastic and collagenous fibers -binds skin to underlying organs -fills spaces between muscles

function of connective tissue

-binds structures together -protects against infection -provides support, protection and framework -fills spaces and stores fat -helps repair damaged tissue

adipose

-cells are adipocytes(store fat in droplets in cells) - cushions joints and some organs, insulates -found beneath the skin, around the kidney/heart, behind the eyes

bone

-composed of cells(osteocytes) in a hard calcified matrix -most rigid connective tissue -osteocytes deposit the bone matrix in layers, lamellae -supports, protects, provides a framework for muscle attachment -stores inorganic salts osteocytes, located in the lacuna, possess cytoplasmic process that pass through canals known as canaliculi -its found in the skeleton and middle ear

elastic connective tissue

-elastic fibers & fibroblasts in a solid gel matrix -connects vertebrae and is found in the walls of arteries and airways -supports, protects, and provides a flexible framework

cell types

-fibroblasts -mast cells -macrophages

elastic cartilage

-it's matrix contains many elastic fibers -found in the outer ear and part of the larynx -supports, protects and provides a flexible framework

elastic fibers

-made of bundles of elastin -air passages/ vocal cords -helps skin return to its original position when poked or pinched

collagenous fibers

-made of thick threads of collagen -they are strong flexible and inelastic -tendons and ligaments

hyaline cartilage

-most common -found in the ends of bones, nose and rings in the respiratory passages - supports, protects and provides a framework -looks like white glass

fibroblasts

-produce fibers by secreting proteins into matrix -most common "fixed" cell -large, star shaped

dense connective tissue

-thick collagenous fibers, thin elastic fibers & fibroblasts in a fluid-gel matrix -found in tendons, ligaments(regular) & the dermis of the skin(irregular) -binds organs together -poor blood supply

fibrocaritilage

-toughest -found between the vertebrae(intervertebral discs), in the knee and parts of the pelvic girdle -supports, protects and absorbs shock during movement

fiber types

collagenous fibers elastic fibers reticular fibers

blood

erythrocytes-RBC leukocytes-WBC -its found in blood vessels -composed of cells and platelets in a fluid matrix, the blood plasma - transports gases, nutrients and wastes, defends against disease and acts in clotting

3 types of cartilage

hyaline elastic fibrocartilage

macrophages

originate as WBC, they can move and phagocytize foreign particles

mast cells

release heparin-prevents blood clotting release histamine-which aids in inflammatory response

reticular fibers

thin collagenous fibers form branched networks for support