TYPES OF EPITHELIA, GLANDULAR EPITHELIUM

1. TYPES OF EPITHELIA, GLANDULAR EPITHELIUM Dr. Katalin Gallatz

2. FUNCTION AND TYPES OF EPITHELIUM COVERING EPITHELIUM • 1. Covering and protecting surfaces • 2. Diffusion • 3. Absorbtion • 4. Excretion • 5. Secretion 6. Sensation 7. Contractility GLANDULAR EPITHELIUM SENSORY EPITHELIUM MYOEPITHEL

3. Covering and protection – Covering epithelium 1. epithelial cells cover the external and internal surfaces, 2. protect underlying tissue from mechanical injury, harmful chemicals, invading bacteria and from excessive loss of water. Diffusion Simple squamous epithelium promotes the diffusion of gases, liquids and nutrients( walls of capillaries and lungs).

4. Characteristics of covering epithelia 1. Cells of the epithelium are closely packed. 2. Junctional complexes can be found beetween the cells. 3. Small amount of intercellular substance 4. Cells form one or more layers. 5. Cover or line all internal and external body surfaces. 6. Basement membrane separates it from the underlying tissues

5. I. Basal lamina • a. lamina lucida • b. lamina densa • II. Reticular lamina BASEMENT MEMBRANE COMPONENTS:

6. Types of covering epithelium Covering epithelium can be divided into two groups depending on the number of layers 1. simple epithelium is only one cell thick 2. stratified epithelium is two or more cells thick

7. Simple epithelia: simple squamous simple cuboidal simple columnar pseudostratified ciliated columnar simplesquamous simplecuboidal pseudostratifiedcolumnar simplecolumnar

8. Simplesquamousepithelium and simplecuboidalepitheliumfromkidney

9. simplecolumnar and pseudostratifiedcolumnarepithelium columnar cells basal cell

10. Stratified epithelia stratified squamous non keratinised stratified squamous keratinised stratified cuboidal stratified columnar transitional epitheliu

11. Stratifiedsquamousepithelium non keratinized keratinized

12. Stratified columnar epithelium 3. Stratum columnare 2. Stratum spinosum 1. Stratum basale

13. Transitional epithelium (urothelium) 3.Umbrella cell layer 2. Pear- shaped cells 1. Stratum basale

14. Glandular Epithelium • Epithelialare cells specialized to produce secretion.. • Secretion – exocytotic release of products, (not metabolic wastes) • Molecules to be secreted may be stored in membrane bound secretory granules

15. Glands are classified as : • ENDOCRINEandEXOCRINE depending on their route of secretion

16. Formation of the exocrine and endocrine glands

17. ENDOCRINE GLANDS • Secretory products called hormones, are secreted directly into the blood • No ducts

18. ENDOCRINE GLANDS

19. Exocrine glands can be classified according to the A) Number of cells Uni- or multicellular B) Mode of secretion holocrine, apocrine, merocrine D) Shape tubular, alveolar (acinar), tubuloalveolar C) Secretory products mucous and serous

20. EXOCRINE GLANDS • release their products onto the free surface of the skin or mucous membranes • mucouos membranesof tubular organsof the digestive, respiratory or reproductive tracts.

21. Classification accordingto the number of the cells 1.Unicellular 2. Multicellular A.) simple (one unbranched duct)- sweat gland B.) compound (branched ducts) parotid gland

22. Unicellular glands • They are scattered among other non-secretory epithelial cells • They have no ducts, but they secrete their products directly on the free surface • The most common unicellular exocrine glands are the goblet cells (mucus secreting cells)

23. Unicellular endoepithelial gland:goblet cell Narrow basal part: nucleus and RER basophilic Apical part: mucin containing secretory granules foamy apperence From Dr. Zita Puskár

24. Unicellular glands

25. Goblet cells trachea small intestine simple columnar epithelium with cuticule Pseudostratified columnar epithelium From Dr. Zita Puskár

27. Demonstration of mucins with differentstainings small intestine PAS large intestine mucicarmin small intestine H.E. redish pale purple From Dr. Zita Puskár

28. EM picture of the goblet cell

29. Multicellular glands a) intraepithelial gland gland is entirely within the epithelium. b) extraepithelial gland below epithelium

30. Multicellular endoepithelial glands In the epithelium of the male urethra From Dr. Zita Puskár

31. Exocrine gland types according to their shape

32. Compound tubuloalveolar mixed gland submandibular gland

33. Modes of Secretion(how products leave the cell) • merocrine - secretion does not affect the well-being of the cell sweat glands, salivary glands, pancreas etc. • apocrine - small part of the cell cytoplasm is lost with the secretion; mammary glands • holocrine - great deal of cytoplasm is lost with the secretion; the cell dies. sebaceous glands

34. Merocrine, apocrine és holocrine secretion merocrine apocrine holocrine Apical part of the cytoplasm with a part of the cell-membrane leaves the surface sebaceaous glands • secretory granules are formed inside the cytoplasm, and leave the cell with exocytosis, pancreas, salivary glands, lacimal gland, sweat glands The whole cell degenerates, dies and forms the secretum mammary gland

35. MEROCRINE SECRETION Sero-mucous gland (submandibular gland)

36. APOCRINE SECRETION mammary gland

37. HOLOCRINE SECRETION SEBACEAUOS GLAND

38. Composition of the secretumA) mucousB) serousC) sero-mucousD) lipid

39. Mucous gland - basally located nuclei - viscous secretory product - well-seen, wide lumen - pale-stained, foamy citoplasm with H.E. Esophagus

40. Serous glands- centrally located nucleus- basophil cytoplasm- narrow lumen- protein-reach fluidy secretum Salivary gland HE Exocrine pancreas HE

41. Serous (pancreatic acinar) cell

42. Mixed sero-mucousgland Gianuzzi’s demilune ducts M S

43. Sero-mucous gland

44. Myoepithelium • Myoepithelium - specialized epithelial cells with powers of contraction, • Surround glandular acini and ducts of many glands, • Contain actin, myosin, cytotokeratin - definitely epithelial in origin

45. Myoepithelial cell in salivary gland

46. Thank you for your attention!