anatomy and physiology: connective tissues

connective tissue components

-specialized cells,
-extracellular protein fibers
-ground substance

connective tissue function

-provide structural support
-fills internal spaces
-stores energy
-transport materials
-blood supply can be vascular or avascular

extracellular matrix

-Non-living material that surrounds living cells
-ground substance and fibers
-determines special function

Ground substance

-mostly water along with adhesion proteins and polysaccharide molecules
-clear, colorless, and viscous
-fills cell space and slow pathogen movement

fibers

-produced by cells
-collagen (white)
-elastic (yellow)
-reticular

collagen fiber

-Strongest and most abundant type (flexible)
-long, straight, unbranched
-Provides high tensile strength
-resist force in one direction

elastic fiber

-Long, thin fibers that form branching networks
-branched and wacky elastin
-allows them to stretch and recoil.

reticular fibers

-short, fine and highly branched collagenous fibers.
-network of interwoven fibers
-resist force in many directions
-strong and flexible

connective tissues categories

-proper: connect and protect
-fluid: transport
-supporting: structural strength

proper connective tissue: loose

-more ground substance, fewer fiber
-packing materials
-areolar
-adipose
-reticular

areolar connective tissue function

-soft packing material web wraps and cushions organs
-support permits independent movement
-can soak excess fluid

areolar connective tissue location

widely distributed under epithelia of body

reticular connective tissue

-Delicate network of interwoven fibers
-Forms stroma (internal supporting network) of lymphoid organs

reticular connective tissue location

lymph nodes, spleen, bone marrow, liver and kidney

adipose connective tissue

-Acts as a storage depot for fat (expand and shrinks)
-provide insulation against heat loss
-padding and cushions shocks
-mesenchymal cells divide & differentiate for more fat & storage

adipose connective tissue location

-under skin
-around kidneys and eyeballs;
-butttocks and breasts

Blood (vascular tissue)

-fluid matrix called blood plasma
-Fibers are visible during clotting
-transport vehicle for materials
-found in blood vessels

red blood cells (erythrocytes)

-transport oxygen and carbon dioxide
-no nucleus

white blood cells (leukocytes)

-respond to injury or infection
-nucleus

Platelets (thrombocytes)

blood clotting

proper connective tissue: dense

-more fibers, less ground substance
-COLLAGEN
-regular
-irregular
-elastic

dense regular connective tissue

-Tightly packed, PARALLEL collagen fibers
-FIRM attachment and stability
-reduce muscle friction

dense regular connective tissue location

-TENDONS: attach muscles to bones

-LIGAMENTS: connect bone to bone and stabilize organs

-APONEUROSES: attach in sheets to large, flat muscles

-DERMIS: lower skin layers

dense irregular connective tissue

Function: able to withstand tension exerted in many directions; provides structural strength

dense irregular connective tissue location

fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract

elastic dense connective tissue

elastic fibers allows recoil after stretching; allows blood flow

elastic dense connective tissue location

Walls of large arteries and walls of bronchial tubes

fibroblast cell

-abundant cell type
-secrete proteins and hyaluronan (cellular cement)
-all proper connective tissue

hematopoietic

pertaining to the formation of blood cells

lacunae

small cavities in bone that contain osteocytes (bone cells)

hyaline cartilage

-Most common type of cartilage
-reduce bone friction
-stiff but somewhat flexibility

hyaline cartilage location

ends of long bones, ribs, and nose

elastic cartilage function

maintains the shape of a structure while allowing great flexibility

elastic cartilage location

external ear, epiglottis

fibrocartilage function

-tensile strength with the ability to absorb compressive shock
-prevents bone to bone contact

fibrocartilage location

intervertebral discs, pubic symphysis, discs of knee joint

cartilage growth

-Interstitial: enlarges cartilages INSIDE
-Appositional: cartilage growth OUTSIDE

bone (osseous tissue)

-bone cells (osteocytes) in lacunae
-hard matrix of calcium salts
-protect and support the body
-periosteum: cover bone (fibrous outer/cellular inner)

mesenchyme cells

-stem cells that respond to injury or infection
-first embryonic connective tissue
-differentiate into fibroblasts and macrophages

mast cells

-respond to injury, infection, or allergy
-releases heparin and histamine

superficial fascia

Separates skin from underlying tissues

deep fascia

Sheets of dense regular connective tissue

subserous fascia

between serous membranes and deep fascia that lines body cavities

fasciae

connective tissue layers and wrappings that support and surround organs