Introduction to practical histology

S.H.

Histology is:

• study of tissues (cells + extracellular matrix) in the body & how are arranged to constitute organs.

• This method by preparing histological:-

• Thin & transluscent sections examined by

• transillumination in the light microscope. (light passing through the tissue.)

Tissue preparation for microscopic examination:-(paraffin

method)

• 1-Fixation: ( e.g.10% formal saline)=.prevent autolysis

•

• 2-Dehydration & Clearing:- = transperancy

• ( ethanol) (xyline)

• 3-Embeding: -hard+solid tissue = (paraffin media)

• 4-Sectioning : 3-5 micron by (microtome)

• 5-Mounting + Staining:

Tissue processor

Embeding (block)

microtome

Staining techniques

• Tissue treated through :

• dewaxaion(Xylene) ---hydration(ethanol)--

water-—(H:E ) ---dehydration----Xylene—

D.P.X(mounting media)---labeling

• Dye either:

• 1-Common staining hematoxylin & eosin.

• Or:

• 2-Special staining method-----

Histology is study of:3 -dimentional

mental pictures of cells

Magnification:

( image )

4,10,20,40,100,

Objective lens

Blood smear :GIEMSA STAIN

BASOPHILIC NUCLEOUS

Lymphocyte

NEUTROPHIL

nucleous

neuron:- BASOPHILIC soma=Nissl

bodies,nucleolus

• Axon

nucleous

dendrite

Hyaline Cartilage(e.g :Trachea)

Pseudostratifiedcolumnar

Ciliated epithelium

ح

؛

ح

perichondrium

Territorial + interterritorial zone

Nest =isogenous gp.

BASOPHILIC MATRIX=GAG

Cytoplasm:- Basophilic =Chief cell

Acidophilic = parietal cell

muscle

Acidophil- tissue

( skeletal)- Esophagus

Inner circular

Outer longtudinal

Bone: Acidophil tissue

PERIOSTEAL BONE

COLLAR

:

Bonemarrow

cavity

fibers:- Collagen(H&E)stain =skin dermis

Osteocyte in lacuna

matrix

MASSON’S

TICHROME

STAIN

(B.V.)

Collagen is green

Elastic fibers- elastic stain:

orcein(aorta)

tunica media

Black Elastic sheets

reticular fibers- (dark brown-Silver impregnation

Liver stroma

. CV

Reticular fibers (AgNO3=argyrophilic)

CV

Liver tissue of different stains:

CV

H&E-

parenchyma

PAS

silver

Liver parenchyma-cells (H&E) stain

Portal

vein

He.

Liver: P.A.S reaction

glycogen=(inclusion)

hepatocytes

Liver: P.A.S reaction glycogen=(inclusion

Kidney-P.A.S rxn: basement

membrane+brush border

Villus of small intestine-striated

border&goblet cells

L.P.

Mesentry spread (H&E stain

Basic

dye

Mast cell (aniline blue stain) =metachrasia

(Mesentry spread)

Mast cell

Lipid (inclusion) in adipocyte- H&E stain

Sudan

black

stain 4

lipid

osmium: stain lipid (black myelin)T.s.in

nerve fiber

axon

Endo-neurium

Melanosomes

Melanin pigment(inclusion) H&E stain

melanocyte