Chap 4 - connective tissue, ground substance, fibers

connective tissue is the most

abundant

example of connective tissue

• adipose/fat

• patellar tendon

connective tissue is mostly _________

non-cellular

major function of connective tissue

• binding

• protection

• transportation

• insulation

common properties of connective tissue

• common origin - mesenchyme

• ECM

strucutral elements of connective tissue

• ground substance

• fibers

• cells

Proteoglycan structure

1) cell adhesion

2) proteoglycans

3) interstitial fluid

cell adhesion proteins (proteogluycan structure)

• connects tissue cells to matrix elements

• laminin and fibronectin connect cell surface protein to fibers

Proteoglycans (proteoglycan structure)

• hellava sugar with some protein

• attracts water

• hylaronic acid

interstitial fluid (proteogluycan structure)

• weakly polar molecule

• beach wave example (connection of water molecues that dont break)

• surface tension **

Fibers are

complex proteins

3 types of fibers

• collagen

• elastic

• reticular

Collagen fibers

• resist stretch / has great tensile

• Ex: tendon that connect kneecap to fibia = collagen

• collagen is secrete in extracellular space

• only animals have collagen **

elastic fibers

• elastin protein with some collagen

• ability to stretch

• found in skin, lung, blood vessel

• Emphysema example

reticular fibers

• delicate networks

• basement membranes

• support soft tissues

4 types of connective tissue

proper, cartilage, bone, blood

Proper tissue has:

• loose connective tissue

• dense connective tissue

types of loose connective tissue

areolar, adipose, reticular

types of dense connective tissye

regular, irregular, elastic

cells under connective tissue proper

• fibroblasts

• fibrocytes

• defense cells

• adipocytes

matrix of connective tissue proper

• gel like ground substance

• collagen, reticular, elastic

fibroblasts are important because

• mitotically capable cells & do most of the work

• produce all the different types of connective tissue

adipocytes are derived from _____

fibrocytes

3 types of cartilage

• hyaline

• elastic

• fibrocartilage

cells of cartialge

• chondroblasts

• chondrocytes

matrix of cartilage

• gel like ground substance (helps take care of load of body weight)

• collage, and SOME elastic fibers

chondroblasts/cytes importance within the cartilage

• blasts = build

• blasts can become chondrocytes

• chondrocyte can still produce collagen fibers and ground substance

two types of bone

• compact bone

• spongey bone

cells of the bone tissue

• osteoblasts

• osteoclasts

matrix of bone tissue

• ground substances with inorganic salts

blood

• hematopoietic stem tissue

• bone marrow

blood can produce

platelets

cells of blood

• RBC

• WBC

• platelets

matrix of blood

• plasma

• NO fibers

• cells secreting fibers

• gives rise to all other connective tissue types

• in embryo

embryonic mesenchyme

• fiber with lots of ground substance

• cushions organs

• distributed under epithelia of body

loose areolar

• fibroblasts CAN become adipocytes

• insulates against heat loss; supports & protects organs

• in breaksts/around kidneys

Loose adipose

• has fibers that supports multiple cells (WBC/mast cells)

• lots of ground substances

• lymph nodes

loose reticular

• fibers all flow in the same direction

• major cells type is fibroblasts

• attaches muscle to bones

• withstands tensile stress

• in tendons + ligaments

dense regular

• major cell type is fibroblast

• withstand tension + structural strength

• fibers are running in different directions

• in dermis of skin

dense irregular

• found in blood vessel

• ability to stretch and recoil

• in walls of large arteries

elastic

all connective tissue proper is produced by

fibroblasts