Connective Tissue Functions mainly to bind and support other tissues

Areolar Tissue is loose connective tissue that consists of a meshwork of collagen, elastic tissue, and reticular fibres - with many connective tissue cells in between the meshwork of fibres. Found in dermis also found in or around mucous membranes, and around blood vessels, nerves, and the organs of the body.blood vesselsnerves

Adipose Tissue loose fibrous connective tissue packed with many cells (called "adipocytes") specialized for storage of triglycerides more commonly referred to as "fats". Adipose tissue forms a thick layer under the skin, around the kidneys and in the buttocks. More generally, it is found at the same locations throughout the body as areolar connective tissue.skinkidneysareolar connective tissue Specific examples of the locations of adipose tissue include: o Subcutaneous layer deep to skin o Around the heart o Around the kidneys o Yellow marrow of the long bones o Padding around the joints o Inside the eye-socket, posterior to the eyeball.

White adipose tissue (WAT) or white fat is one of the two types of adipose tissue found in mammals. brown adipose tissue. o Found in newborns and hibernating animals

Connective tissues have a sparse population of cells scattered through an extracellular matrix Matrix generally consists of a web of fibers. o May be liquid, jellylike or solid In most cases, the connective tissue cells secrete the matrix

Connective Tissues Unlike epithelial tissues, connective tissues have abundant matrix (intercellular material) and have a good blood supply (expect cartilage)

Fibroblast is common cell type o Star shaped o Secretes high amounts of protein

Leukocytes are a type of white blood cell wonder around connective tissues Macrophages function as scavenger cell and defend against infection

macrophage

Leukocytes Neutrophils o Most numerous (~60%) o Only occasionally found outside of blood o Anti-bacterial cells which lyse bacterial cells o Rapidly gather during inflammation Eosinophils o 2-4% o Associated with allergies and parasites Basophils o >1% o Seems to function similar to mast cells, involved in inflammation Monocytes o largest WBC, 5% o Same function as macrophages – engulf and digest Lymphocytes o 30% o Commonly found in connective tissues o Respond to inflammation, mediating and regulating immune responses

Mast Cell located throughout connective tissues adjacent to blood vessel o Help release heparin and histamine

Proteins within the connective tissues Three kinds of connective tissue fibers o Collagenous fibers Made of collagen protein. Collagenous fibers are nonelastic and do NOT tear easily o Elastic fibers Made of protein called elastin o Long threads o Elastin fibers provide a rubbery quality o Reticular fibers Most thin highly branched Attached connective tissue to surrounding tissue

Collagenous fibers Elastic fibers Reticular fibers

loose connective, adipose tissue, fibrous connective tissue, cartilage, bone and blood

Loose Connective Tissue Found throughout body Binds body parts together Such as skin and underlying organs Majority are fibroblasts o separated by gel-like substance o Containing collagenous and elastic fibers

Loose connective tissue binds epithelia to underlying tissues and functions as packing materials, holding organs in place

Fibroblasts – secrete protein ingredients of the extracellular fibers Macrophages – WBC that roam the maze of fibers, engulfing bacteria and debris of dead cells

Adipose Tissue Specialized form of loose connective tissue Adipose tissue pads and insulates the body Stores fuel as fat molecules Each cell swells when fat is stored and shrinks when the body uses fate as fuel

Fibrous Connective Tissue Extremely dense due to large amounts of collagenous fibers Organized into parallel bundles to maximize strength Tendons Ligaments

Tendon

Cartilage Has an abundance of collagenous fibers embedded in rubbery matrix o Matrix is made of protein-carbohydrate complex Chondrocytes secrete collagen Collagenous fibers make cartilage strong yet flexible Skeleton of shark is made of cartilage Animals are made of embryonic skeletons are cartilaginous Flexible supports Pinna, vertebral disks

Cartilage Lacks a vascular system Heals slowly Cartilage cells (chondrocytes) lie within lacunae in the gel like fluid matrix

Hyaline Cartilage Most common cartilage White in color Abundant fine collagen fibers Found at the end of the bone Supports respiratory system

Hyaline cartilage in the trachea

Elastic Cartilage Stains a little darker Made with elastic fibers Provides framework for external ears & part of larynx

Fibrocartilage Helps absorb shock Found in intervertebral disks, knees and pelvis Tough tissue with many collagenous fibers

Bone Extremely dense! Most rigid connective tissue Deposits of mineral salts and collagen within the matrix Protein and salt ratio is just perfect Internal support of body Protects Forms muscle attachments Cite for blood cell formation Stores fats

Skeleton is made of bone, a mineralized connective tissue Matrix of collagen (flexible) and minerals (hard) o Calcium, magnesium, phosphate ions

bone Structure of bone - Repeating units called osteons Each osteon has a concentric layers of mineralized matrix deposited around a central canal containing blood vessels and nerves that service the bone Arranged into osteons or Haversian systems o Store calcium salts o Withdraw Lacking calcium in diet Create embryo

Blood Matrix called plasma Mainly water, salts and variety of dissolved proteins Suspended in plasma are erythrocytes (red blood cells), leukocytes (white blood cells) and cell fragments called platelets o Red blood cells carry oxygen o White cells function in defense against viruses, bacteria and other invaders o Platelets aid in blood clotting