1. Textus epithelialis Štěpán Jelínek
Epithelial tissue
Textus epithelialis
Štěpán Jelínek

2. Characteristic of epithelium
cells
foundation is basal lamina
minimum of extra cellular matrix
plenty of intercellular junctions
various shapes – important for classification
variability of functions

3. Basal lamina thin layer of extracellular matrix two layers
collagen IV. type, laminin, proteoglycans
two layers
lamina rara, lamina densa
lamina reticularis – part of connective tissue
foundation for epithelial cells
produced by epithelial, muscular, Schwann‘s cells and adipocytes

4. Basement membrane two connected basal laminae
on the border of two epitheliums
lung, kidney
two laminae rarea, one lamina densa
basal lamina and lamina reticularis
visible in light microscope
PAS positive

5. Function of basal lamina
barier
selection in transport - proteoglycans
selection of cells – laminin
regeneration
wound healing, NM junction
polarisation and migration of epithelial cells

7. Polarity apical part of cell basal (basolateral) part of cell
lumen of organ, surface of organ
basal (basolateral) part of cell
basal lamina in contact with lamina propria

8. Lamina propria contains vessels and nerves
mechanical support of epithelium
connects epithelium to another layers
usually undulated surface - papillae

10. Specialisations of cellular surface
free surface
microvilli, stereocilia, cilia
lateral surface
intercellular junctions, interdigitations
basal surface
connection with BL, basolateral labyrinth

11. Microvilli, stereocilia, cilia
non-branching projections of cell
enlargement of cell surface
stereocilia
branched non – motile projections
cilia
non-branching motile projections
transport of extracellular mass

13. Intercellular junctions
adhesive
zonula adherens (belt desmosome)
desmosome (macula adherens)
hemidesmosome
occluding
zonula occludens (tight junction)
communicating
gap junction (nexus)

15. Intercellular junctions (belt)
Zonula occludens
cell. membranes without intercell. space
five layers of membrane
Zonula adherens
intercell. space about 20 nm
thicker membrane
connected with cytoskeleton

16. Intercellular junction (spot)
Desmosome
intercell. space about 30nm
sometimes dark plate
connected with cytoskeleton
hemidesmosome
connection between cell and BL
Nexus (gap junction)
intercell. space about 2 nm
connexons – forms pores for ion transport

19. Regeneration of epithelium
fast and complete
faster with complete BL
continual regeneration of cells
stem cells
small intestine – 3 days
skin - 27 days

20. Types of epithelial cells
transporting cells
signalising cells
synthesizing and exporting cells
myoepithelial cells
stem cells

21. Transporting cells cells transporting ions (active)
microvilli, basolateral labyrinth
prox. a dist. tubule of kidney, striated ducts of sal. gl.
cells transporting using pinocytosis
transport of larger molecules
pinocytic sacs
endothelium

22. Signalising cells release signal molecules neurocrine cells (neurons)
distribution across synapse
paracrine cells (DNES)
distribution – diffusely to ECM
secretory granules in basal part of cell
endocrine cells (suprarenal)
distribution - transport by blood stream
ultrastructure depends on type of substance

23. Synthesising and trasporting cells
proteins
synthesis, modification, storage
serous cells of sal. gl., serous cells of pancreas
glycoproteins of mucus
mucus (lighter than cells prod. proteins)
mucous cells of sal. gl., goblet cells
steroids
lipid droplets, sER, tubular MIT

25. Myoepihelial cells cytokeratins, contractile microfilaments
acins and tubules of sweat, salivary, lacrimal gl.

26. Stem cells
maternal
undiferetiated
regeneration of epithelium

27. Classification of epitheliums
acording to spatial arrangement
flat
trabecular
reticular
according to function

28. Flat epithelium according to count of layers
simple
stratified
pseudostratified, transitional
according to shape of cells
squamous
cuboidal
columnar
keratinised and non-keratinised

29. Single layered squamous

30. Single layered cuboidal

31. Single layered columnar

32. Single layered columnar with cilia

33. Pseudostratified with cilia

34. Stratified squamous

35. Transitional

36. O2 – muscular artery

37. O1 - kidney

38. O3 – thyroid gland

39. O4 - colon

40. O5 – uterine tube

41. epidydimis

42. O6 - esophagus

43. O7 - skin

44. V10 - trachea

45. O8 – urinary bladder

46. Trabecular epithelium
cells in cords
cords form web
between cords are capillaries, nerves
liver, adrenal, pituitary

47. E8 - adrenal AZAN

48. Reticular epithelium cells are in contact only with their processes
cells form web
in „holes“ of web are other cells
thymus, bone marrow

49. Classification according to function
epithelium covering - skin
epithelium resorbtional - intestine
epithelium respiratory - lung
epithelium sensory – olfactory ep.
epithelium muscular – myoepithelial c.
epithelium germinal – testes
epithelium secretory - glands

50. Glandular epithelium cells producing and releasing substrate
this substrate is used by organism
type of secretion
merocrine (pancreas)
apocrine (mammary gland)
holocrine (sebaceous gland)

51. Types of gland exocrine endocrine excretion to lumen of organ
have ducts
endocrine
do not have ducts
excretion to blood capillaries

52. Types of exocrine glands
according to shape of secretory and excretory parts
simple glands
compound glands
tubular
alveolar (acinar)
tubulo-acinar

53. O9 – glandula sublingualis

54. O10 - pancreas

55. The end