1. بسم الله الرحمن الرحيم

2. INTRODUCTION TO HISTOLOGY

3. HISTOLOGY (MICROSCOPIC ANATOMY) Definition.

4. Light Microscope (L/M) 1- Illumination. 2- Magnification. 3- Resolution. N.B. Resolving power ( It is the least distance between 2 particles at which they will appear separated). R.P. for L/M is 250 nm

5. Light microscope

6. STAINING FOR L/M Staining with Hematoxylin and Eosin (H&E) or (Hx&E): Basophilic structures. Acidophilic structures.

7. (B) Electron microscopy: 1-Transmission E/M: Resolving power 0.2 nm. * Electron-dense structure **Electron-lucent structure 2-Scanning E/M: Resolving power 10 nm.

8. Transmission Electron Microscope

9. Scanning Electron microscope

10. THE CELL

11. THE CELL NUCLEUS (INTERPHASE NUCLEUS)

12. Shape of nuclei

13. Dark Nucleus (Deeply-stained nucleus)

15. Vesicular (open face) Nucleus

17. L/M: Appearance (Type): - Light nucleus (vesicular) (open face) - Dark nucleus (deeply-stained) Number: 1, 2, or more. Position: Central, eccentric, peripheral, basal. CELL NUCLEUS (Interphase Nucleus)

18. Cell Nucleus L/M (cont.): Size: Small, medium, large ( Nucleus/cell ratio) Shape: e.g. Rounded, oval, rod-shaped.

19. Nucleus (E/M diagram) RER------- Hc

20. Nucleus (Electron Micrograph) PRACTICAL

21. Nuclear pores PRACTICAL

22. Cell Nucleus (Interphase nucleus) E/M: (1) Nuclear envelope Inner nuclear membrane. Outer " ". Nuclear pores. Nuclear pore complex. Perinuclear cisterna. Nuclear lamina. N.B. Rough Endoplasmic reticula (Relation with,).

23. (2) Chromatin: ( Classification ): According to Metabolic activity: a- Euchromatin(Extended chromatin) b- Heterochromatin( Condensed chrom. ) According to Position: a- Peripheral chromatin. b- Nucleolus-associated chromatin. c- Chromatin islands.

24. Nucleolus (E/M)

25. (3) Nucleolus: L/M: 1-5 basophilic bodies E/M: 1- Pale-staining fibrillar center. 2- Pars fibrosa: containing rRNA (nRNA) being transcribed.

26. Nucleolus (cont.): 3- Pars granulosa: maturing ribosomal subunits are assembled. 4- Nucleolar matrix. N.B. Nucleolus is a non-membranous structure. Function of nucleolus: rRNA synthesis.

27. NUCLEOPLASM 1- Nuclear matrix. 2- Ribonucleoprotein. 3- Interchromatin granules. 4- Perichromatin granules.

28. CYTOPLASM (1)Organelles. (2)Inclusions. (3)Cytosol.

29. Cytoplasmic organelles 1- Cell Membrane. 2- Ribosomes. 3- Endoplasmic Reticulum. 4- Golgi Apparatus. 5- Endosomes 6- Lysosomes. 7- Peroxisomes. 8- Mitochondria. 9- Cytoskeleton. 10-Centrioles. 11-Cilia & flagella. 12-Filaments (thin f., intermediate f., thick f.).

30. Cytoskeleton 1- Thin Filaments (actin filaments). 2- Intermediate Filaments. 3- Microtubules.

31. Specializations of cell membranes (1)Microvilli. (2)Cilia. (3)Intercellular junctions.

32. Cytoplasmic Inclusions 1- Glycogen. 2- Lipids. 3- Pigments: e.g. lipofuscin pigments, melanin. 4- Crystals. 5- (Secretory granules).

33. CELL MEMBRANE (PLASMALEMMA)

34. Cell Membrane (Plasmalemma)

35. CELL MEMBRANE & GLYCOCALYX

37. GLYCOCALYX (CELL COAT)

38. MICROVILLI

39. MITOCHONDRIA

40. PRACTICAL

41. ENDOPLASMIC RETICULUM

42. ROUGH ENDOPLASMIC RETICULUM

43. RER & SECRETORY GRANULES

44. GOLGI APPARATUS

47. LYSOSOMES

49. CILIA

51. CILIA & CENTRIOLES

52. CENTRIOLES

54. MICROTUBULES & ACTIN FILAMENTS

55. DISTRIBUTION OF MICROTUBULES IN INTERPHASE CELLS 1- Cytoplasmic microtubules. 2- Cilia. 3- Flagella. 4- Centrioles.

57. Glycogen granules in hepatocyte

58. INTERCELLULAR JUNCTIONS

59. (1)Occludent junction. (2)Adherent junction. (3)Gap junction (Nexus).

60. OCCLUDENT JUNCTION (TIGHGT JUNCTION)

61. DESMOSOMES (Macula adherent junctions)

62. GAP JUNCTION (NEXUS)

63. JUNCTIONAL COMPLEX