Chapter 3Chapter 3connective connective

tissuetissue

IntroductionIntroduction

1.Concept :

act as connection 、 supporting 、

nutrition 、 protection

2.Characteristics:

1. a few cells and a lot of intercellular substance which consists of fibers and ground substance

2. no polarity: internal environment tissue

3. more varieties and distributing widely

4. originate from mesenchyme:

Mesenchyme mesenchymal cell + matrix star shaped cell (with processes ) ，ovoid nucleus withprominent nucleolus multipotential cells

Differentiate: endothelial cells, smooth muscle cells,

fibroblast and fat cell.

3.Classification of CT:

according to the ground substance: loose CT

1. gelatinous matrix: dense CT

connective tissue proper adipose T

reticular T

2. solid gel matrix: cartilage and bone

3. fluid matrix: blood

1. Loose connective tissue ：

more ground substance with loosely arranged cells

and fibers,

areolar tissue 蜂窝组织 Distribute widely,

7 types of cells

3types of fibers

(1) Cells:

1. fibroblast

flattened cell with processes,

flattened nucleus, pale staining,

basophilic cytoplasm,

EM: RER, ribosomes,

Golgi complex

Function: synthesize collagen, elastin to form fibers

synthesize glycoprotein and proteoglycan to form

ground substance

fibrocyte: resting fibroblast, smaller, acidophilic cytoplasm

2. Macrophage ( histocyte)

structure:

different shape ,

processes,

small nucleus

– round / kidney ,

dark staining,

acidophilic cytoplasm,

phagocytotic granule

EM:

microvillus

primary lysosomes

secondary lysosomes phagosome phagocytotic vacuoles residual body microfilamentmicrotubul

functions:

(1) phagocytosis ： chemotaxis 趋化性 , ameboid

movement

chemotactic factor

( Specific and nonspicific )

(2) present antigen joining

and regulating immuno-

response

(3) secrete some materials joining immunoresponse

lysozyme , interferon, interleukin , complement

3. plasma cell

structure:

ovoid cell, round and

eccentrically placed

nucleus, coarse hetero-

chromatin (clock-face

appearance)

prominent nucleolus ,

basophilic cytoplasm

RER, ribosome Golgi complex,

Function : secrete antibody—immunoglobulin Ig

4. mast cell

structure: large cell, small nucleus, pale metachromatic basophilic granules ，

● eosinophil chemotaxti

factor

● heparin prevet

blood coagulation

● histamine ,leukotriene

anaphylaxis( 过敏 ):

first time: plasma cell→IgE + receptor (mast cell)→activated condition

Second time : antigen-antibody complex –join together-- relea

sing histamine and leukotriene → asthma ( 哮喘 ) or hives ( 荨麻疹 )

Antigen contact

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二次抗原进入...

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........anaphylaxis( 过敏 ):

Receptor of IgE

5. fat cell

structure: round 、 polyhedral ,large lipid droplet

vesicle ， cytoplasm ， flatten nucleus

function: synthesize and store fat

7. white blood cell:

acidophil ,neutrophil and lymphocyte

6. undifferentiated mesenchymal cell

structure: resemble fibroblast

function: differentiate fibroblast,fat cell,

smooth m.f. and endothelial cell

(2).FiberS

1. collagenous f (white f ) :

structure: 1~20μm acidophilic,

network fibrils

collagen ---collagenous fibil

(20--300nm),

64nm →cross striation

function:

flexible and

strongly resist a pulling force, 韧性 , 抗拉力

2. elastic fiber ( yellow f ) :

structure ： meshwork

HE---light pink ， 0.2~1.0μm

aldehyde fuchsin 醛复红— purple ，

composition:

homogeneous elastin

covered by microfibril

function: elasticity

elastic fiber

3. reticular fiber :

structure: 0.2~1.0μm , branch a lot, meshwork ， silver stain--- argyrophilic fiber 嗜银纤维

composition: collagen fibrils covered by glycoprotein,

PAS positive

distribution: more in lamina reticularis

hematopoietic organs

function: make hematopoietic

microenvironment

(3). ground substance

composition: proteoglycan and glycoprotein

1.proteoglycan: glycosaminoglycan: hyaluronic acid ,chondroitin

sulfate A and C , keratin sulfate , heparan sulfate and dermatan sulfate

Protein: link protein core protein

2.glycoprotein: fibronectin,FN laminin,LN chondronectin, ChN

(3). ground substance

hyaluronic acid

link protein

core protein

glycosaminoglycan

proteoglycan subunit

分子筛 molecular sifter

Function of ground substance:

supply a place for materials exchange

act as barrier to prevent the bacteria,large

molecules from entering

cancer cell

streptococcus

hyaluronidase destroy

the barrier

动脉端动脉端 静脉端静脉端

tissue fluid

毛细淋巴管毛细淋巴管

capillarycapillary

tissue fluid: suitable for materials exchange edema, dehydration

2.Dense connective tissue

structure:

bundles of collagen fibers arranged densely ,

small amount of

ground substance

and cells .

Classification of dense C.T

  1. regular dense CT:

tendon, ligament

fibroblast→ tendon cell

2. irregular dense CT:

dermis of skin,capsule of organ ,

sclera of eye ,dura mater

3. elastic tissue: ligament nuchea 项韧带， ligament

flava 黄韧带 ,elastic membrane

3.Adipose tissue

Fat cells and loose connecive tissue

1. yellow adipose tissue(white):

fat cells : contain a large lipid droplet

univesicle fat cell

2. brown adipose tissue:

fat cells : contain numerous small lipid droplets

multivesicle fat cell

round nucleus centrally located

4. Reticular tissue: reticular cells and reticular fibers

function:

providing microenvironment for hematopoiesis.