Connective tissue (1)

1.Loose connective tissue (No.4, No.1 )

2.Dense connective tissue (No.14)

3.Adipose tissue (No.14/ No.6)

4.Reticular tissue (No.6)

1. General features: 1) small number of cells and large amount of extracellular matrix (intercellular material). 2) the extracellular matrix is composed of fibers and an amorphous ground substance. 3) functions: connection, supporting, protecting, nutrition, defense and repairing.

2.  Classification

Connective tissue proper Cartilage Bone blood

The types of CT are determined on the basis of the types of cell and the characteristics of the extracellular matrix

CT in narrow sense means CT in narrow sense means connective tissue properconnective tissue proper, , include:include:

loose CTloose CT adipose tissueadipose tissue reticular tissuereticular tissue dense CTdense CT

connective tissue proper

LCT ： HE X400

Material: rabbit mesentery

Slide No:4

High power:

1. Elongated and tortuous collagenous fibers are stained red and arranged in bundles.

2. The elastic fibers are blue stained, branched and formed a woven network.

3. The fibroblast is the cell most commonly in close to the collagen fiber. Its basophilic nucleus is visible.

4. For the macrophage, its cytoplasm contains some blue dye substance.

Loose connective tissue

Low power: fibers are loosely and irregularly arranged.

high power: Elongated and tortuous collagenous fibers are stained red and arranged in bundles.Elastic fibers are blue stained,branched and formed a woven network.

fiber

Fibroblast: the most commonly cell in close to the collagen fiber.only the basophilic nucles is visible,but the acidophilic cytoplasm is not clearly defined.

Cell

Macrophage: ingest the blue dye by phagocytosis so they can be easily identified.

Fibroblast

Macrophage

Small intestine: HE X40

Slide No:1

Method: H.E

lower power:

The lightly stained submucosa between mucosa and smooth muscle layer.

Low power：

1

submucosa

High power:

collagenous fibers are the predominant component and they course in different direction. They are sectioned in various planes and cut ends is seen. stained red and arranged in bundles.

Fibroblast are the most numerous cells ,only the basophilic nucles is visible,but the acidophilic cytoplasm is not clearly defined.

Small intestine: LCT HE X400

Fibroblast

collagenous fibers

Skin :DCT HE X40

Dense connective tissue and adipose tissue

Slide No:14

Material: human skin from finger

Method: H.E

Naked eye: in the section, epidermis is violent stained. Under epidermis, the dermis is pink and composed of dense connective tissue.

In hypodermis, you can find loose connective tissue and adipose tissue.

In the section , epidermis is violent stained. Under epidermis,the dermis is pink and compose of denes connective tissue.

Low power:

epidermis

dermis

high power:

collagenous fibers are the predominant component and they course in different direction. They are dense ,irregularly arranged and formed thic bundles. stained red .The numbers of cells are few, most of which are fibroblasts and fibrocytes.

Dense regularly connective tissue

Tendon(longitudinal section)

High power:Collagenous fibers are arranged in compact,parallel bundles

Tendon cell:

Lymph node: Reticular tissue HE X400

Reticular tissue

Slide No.5

Material: lymph node of cat

Method: H.E

High power:

Reticular cell: A reticular cell produces reticular fiber and surrounds the fibers with its cytoplasm.

It has many processes. Its nuclei is lightly stained, but the nucleolus is clear.

Lymph node: Reticular tissue HE × 400

Reticular tissue

Reticular tissue Reticular tissue

①① reticular cellreticular cell ② ②lymphocyte lymphocyte ③③ macrophagemacrophage

Lymph node: Reticular tissue Silver × 400

Adipose tissue

Material: human lymph node

Method: H&E

Slide NO: 6 Adipose tissue

Low power:

Fat cell are present in large accumulations, orgnized into adipose tissue

Lymph node ： Adipose tissue HE X40

high power:

Individual Fat cells show their chracteristic structure,empty cells,due to solution of fat during section preparation.

The nucleus is pushed to the periphery of the cell.

FibroblastFibroblast Macrophage Macrophage

Mast cells

1.Round and large cell1.Round and large cell2.Small dark-stained nucleus2.Small dark-stained nucleus3.Basophilic secreting 3.Basophilic secreting granules--metachromaticallygranules--metachromatically

Plasma cellPlasma cell

1.Round or ovoid in shape1.Round or ovoid in shape2.Nucleus with more clock-liked heterochromatin which located 2.Nucleus with more clock-liked heterochromatin which located eccentrically eccentrically3.Basophilic cytoplasm3.Basophilic cytoplasm

Collagenous fibersCollagenous fibers collagenous fibrilcollagenous fibril

fibroblast Plasma cell

Mast cell macrophagy

The drawingThe drawing

Loose connective tissue H&E stain 400×

Macrophage

Collagenous fiber

Elastic fibers

Fibroblast