University of Szeged, Faculty of MedicineDepartment of Anatomy,

Histology and Embryology

HISTOLOGY PRACTICE 1.

IntroductionEpithelia

Molnár Gergely2014

Tissue preparation for microscopy

• Fixation: e. g. formaldehyde, alcohols

(dehydration, solvent change)

• Embedding: e. g. paraffin

• Sectioning: microtome – usually 8-20µm thick

(paraffin extraction, solvent change …)

• Staining:

– most common: hematoxylin-eosin (H&E)

– special dyes: PAS, orcein, silver impregnation…

• Covering

The microscopeOcular lens

Objective lens -Revolver

Condenser(Diaphragm)

Stage

Brightness

Stage position adjustment knobs

Mains

Focusing knobs:coarse focus knobfine focus knob

Arm („Handhold”)

Head locking screw

TOTAL MAGNIFICATION: magn. of the ocular × magn. of the objective

The types of epithelial tissues• Covering epithelia

– simple covering epithelia• simple squamous epithelium• simple cuboidal epithelium• simple columnar epithelium• pseudostratified columnar epithelium

– stratified covering epithelia• stratified squamous nonkeratinized epithelium• stratified squamous keratinized epithelium• stratified cuboidal epithelium• stratified columnar epithelium• urothelium (transitional epithelium)

• Glandular epithelia– serous– mucinous

• Sensory epithelium• Pigmented epithelium

34. Kidney (HE, 40x): 1. Simple squamous epithelium Cortex

Renal pelvis

Medulla

renal corpuscle

34. Kidney (HE): 2. Simple cuboidal epithelium

renal tubules

simple cuboidal epithelium

simple squamous epithelium

Cortex

Renal pelvis

Medulla

34. Kidney (HE): 3. Simple columnar epithelium

Renal tubules

Cortex

Renal pelvis

Medulla

simple cuboidal epithelium

simple (low) columnar epithelium

Endothel(simple squamous epithelium)

Cortex

Renal pelvis

Medulla

34. Kidney (HE, 40x): 4. Urothelium (transitional ep.)

Renal pelvis

relaxed urothelium(in ureter)full bladder; stretched state

1 2 3123

1. columnar basal cell layer2. polygonal (pear shaped) cells3. superficial facet („umbrella”) cells

1 2 3

32. Trachea (HE): Pseudostratified ciliar columnar epithelium

?

Lumen

Membranous wall (sectioned)

Tracheal cartilage

Lumen

Kinocilia

20. Esophagus (HE, 40x): Stratified squamous nonkeratinized epithelium

3. Stratum planocellulare

1. Stratum basale(Str. germinativum)

2. Stratum polygonale(Str. spinosum)

Lumen

Basement membrane

54. Finger skin epidermis (HE, 10x): Stratified squamous keratinized epithelium

1. Stratum basale(Str. germinativum)

2. Stratum polygonale

3. Stratum granulosum

4. Stratum lucidum

5. Stratum corneum

EPIDERMIS

DERMISconnective tissue papillaeof the dermis

1. Stratum basale(Str. germinativum)

2. Stratum polygonale

3. Stratum granulosum

4. Stratum lucidum

5. Stratum corneum

EPIDERMIS

Basementmembrane

DERMIS

connective tissue papillaeof the dermis

54. Finger skin epidermis (HE, 40x): Stratified squamous keratinized epithelium

A

C

B

E

A) direction of the secretion: – endocrine

– exocrine: duct + secretory portion

B) type of the secretion:– merocrine

– apocrine

– holocrine

C) type of the secret:– mucous

– serous

D) position of the gland:– endoepithelial

– exoepithelial

E) form of the gland:– simple, coiled, branched and compound

– tubular, alveolar (acinar), tubuloalveolar (tubuloacinar)

Glandular epithel

1. Unicellular glands (small intestine): Goblet cells (40x)(endoepithelial + mucous + exocrine glands)

periodic acid-Schiff stain (PAS) + hematoxylin

Simple columnar epitheliumof intestinal villi

Goblet cells(inflated, PAS-positive granula;displaced basophilic nucleus)

Brush border

32. Trachea ( HE, 20x):

Exocrine glands

(Tracheal glands)

Serous acini

Mucous acini

Giannuzzi’s serous demilune

Lumen

Pseudostratifiedciliated columnarepithelium

Trachealcartilage

Identify the type of the epithelia in the following

sections!Name the structures shown

by the arrows!

1.

2.

3.

4.

?Type of the epithelium?

5.

6.

7.

8.

9.

10.

1.

2.

11.

1.

2.

3.

12.

The type of the gland?

13.

14.

15.

Type of the acini? Name of the staining technique?

Name of the structure?

16.

17.

18.

1.

2.

3.

4.

5.

19.

20.

21.

22.

23.

24.

25.

26.

27.

Correct answers:

1. Simple columnar epithelium (small intestine)

2. Stratified columnar epithelium (male urethra)

3. Urothelium with umbrella cells (urinary bladder)

4. Stratified squamous nonkeratinized epithelium and simple squamous

epithelium (cornea)

5. Pseudostratified ciliated epithelium (respiratory tract)

6. Goblet cells stained with PAS (small intestine)

7. Simple cuboidal epithelium (medulla of kidney)

8. Stratified columnar epithelium (male urethra)

9. Simple columnar epithelium (gallbladder)

10.Stratified squamous keratinized epithelium (skin)

11.Simple columnar epithelium HE + goblet cells (1.), brush border (2.)

stained with PAS (duodenum)

12. Stratified squamous keratinized epithelium (str. granulosum (1.), lucidum (2.), corneum(3.)

13. Stratified columnar epithelium + multicellular endoepithelial gland (male urethra)

14. Pseudostratified ciliated epithelium (tail of the epididymis)15. Mesothelium16. Mucinous acini + ductus salivaris stained for mucin (mucicarmin)

(glandula subligualis)

17. Urothelium with umbrella cells (urinary bladder)

18. Serous acini (parotis)

19. Pseudostratified ciliated epithelium + goblet cells (1.) + demilune of

Gianuzzi (2.) + serous acini (3.) + duct (4.) + mucinous acinus (5.)

(respiratory tract)

20. Stratified squamous nonkeratinized epithelium (esophagus, vagina)

21. Urothelium (ureter)

22. Simple columnar epithelium (uterus)

23. Simple cuboidal epithelium (medulla of kidney)

24. Pseudostratified ciliated epithelium (respiratory tract)

25. Simple ciliated columnar epithelium (oviduct)

26. Simple squamous and cuboidal epithelium (medullary zone of the

kidney)

27. Pseudostratified ciliated epithelium (tail of the epididymis)