1. Histology
What to look for

2. Histology review Histology Practical = 50 pts
Some slides set up on scopes (~10)
Some Powerpoint pictures on the projector
Questions I will ask:
What kind of tissue?
General function? (e.g. absorption, protection)
What cells, fibers, ground?
An example of where would you find it?

3. Slides
Epithelial tissues (7 types, could be ANY of the examples provides)
Connective tissues (11 types, ANY example that we looked at)
Muscles (3 types) or neruons
Integument and accessory structures

4. Epithelial tissue

5. Simple cuboidal epithelium
Lining kidney tubule
Large, spherical, usually central nucleus

6. Another example - kidney

7. Simple squamous

8. Simple squamous Really flat cell layer.
Cytoplasm very thin, visible only at point of central nucleus

9. Kidney

10. Superficial view (squamous)

11. Simple columnar Intestinal lining
Oblong nuclei which may be much closer to one side than the other

12. Simple columnar

13. Pseudostratified Columnar Epithelium
Trachea
Look like multiple layers
ciliated
Figure 4–5b

14. Another example

15. Transitional Epithelium
Urinary bladder
Looks stratified, with no coherent layers and dome shaped cells at the top
Figure 4–4c

16. Transitional

17. Stratified Squamous Epithelium
Skin
Many layers thick, flat cells at top
Figure 4–3b

18. Stratified squamous

19. Stratified squamous

20. Stratified Cuboidal Epithelium
Sweat gland ducts
Two layers with large spherical nuclei
Figure 4–4b

21. Stratified Columnar Epithelium
Salivary gland duct
Only top layer lining lumen looks columnar
Figure 4–5c

22. Connective tissue

23. Connective tissues Bone Connective tissue proper
Loose connective tissue
Areolar
Adipose
Reticular
Dense connective tissue
Dense regular
Dense irregular
Elastic tissue
Fluid CT
Blood
Supporting CTs
Cartilage
Hyaline cartilage
Elastic cartilage
Fibrocartilage
Bone

24. Areolar tissue
A loose CTP

25. Areolar

26. Areolar: what to look for
Fibroblasts
Collagen fibers
Elastic fibers
Mast cells and macrophages
Found? Throughout body, under dermis, divides skin from underlying tissues

27. Adipose tissue
Another lose CTP (note nucleus)

28. Adipose: what to look for
Lots of cytoplasm
Slim nuclei pushed off the side
Found? You know where

29. Reticular tissue
The third type of loose CTP

30. Reticular: what to look for
Reticular fibers (network)
Found? Internal framework in many sort organs (liver, spleen) supporting the parenchyma

31. Dense regular

32. Dense regular: what to look for
Thick parallel bundles of collagen
Thick fibers
Little space in between fibers
Small fibroblast nuclei in between bundles
Found? Tendons, ligaments, deep fascia.

33. Dense irregular

34. More dense irregular

35. Dense irregular: what to look for
Mesh of collagen fibers (irregular looking)
Interspersed fibroblasts
Found? Dermis of skin, periosteum, perichondrium

36. Elastic tissue

37. Elastic tissue

38. Elastic tissue: what to look for
Elastic fibers (instead of collagen fibers) in large bundles
Smaller width fibers
More space in between fibers
Fibroblast nuclei (sometimes visible)
Found? Between vertebrae, in blood vessel walls (underneath endothelium)

39. Fluid CT
Blood

40. Blood: what to look for RBCs
White blood cells (darker): monocytes, lymphocytes, granulocytes
Platelets

41. Supportive CT Cartilage – gelatinous, padding Hyaline cartilage
Elastic cartilage
Fibrocartilage

42. Hyaline cartilage
Glasslike because fibers not visible

43. More hyaline
There are collagenous and elastic fibers lying in the cartilage matrix but they are invisible because their “refractive index” is the same as that of the matrix (like cornea)

44. Hyaline cartilage

45. Hyaline
Hyaline cartilage (lavender matrix), with perichondrium (pink) outside it. The latter is a dense regular collagenous CT. Cartilage cells = chondrocytes, and they are lying in the lacunae.

46. Hyaline cart.: what to look for
Perichondrium
Chondroblasts (make the matrix fibers and ground)
Chondrocytes and lacunae
Where? Most joints, nasal septum

47. Elastic cartilage

48. Elastic cartilage

49. Elastic cart: what to look for
Many elastic fibers in matrix (or sometimes to the sides)
Chondrocytes in lacunae, often stacked up like a totem pole
Found? External ear

50. Fibrocartilage

51. Fibrocartilage: what to look for
Irregular, wispy collagen fibers
Chondrocytes in lacuna
Found? Intervertabral discs of spine, pads in knee joint

52. Supportive CT: Bone

53. Bone: what to look for Osteon (whole circular structure)
Concentric lamellae (of matrix)
Central canal (at center of lamellae)
Osteoblasts
Osteocytes in lacunae
Canaliculi
Found? Bones!

54. Nervous Tissue
Figure 4.10

55. Nervous Tissue
Figure 4.10

56. Nervous tissue: what to look for
Large, pyramidal cell bodies
Long processes extending out
Space (it’s a smear so cells don’t usually take up the whole area)
Found? Nerves, CNS

57. 3 Types of Muscle Tissue Skeletal muscle: Cardiac muscle:
large body muscles responsible for movement
Cardiac muscle:
found only in the heart
Smooth muscle:
found in walls of hollow, contracting organs (blood vessels; urinary bladder; respiratory, digestive and reproductive tracts)

58. Muscle Tissue: Skeletal
Figure 4.11a

59. Muscle Tissue: Skeletal
Figure 4.11a

60. Skeletal Muscle: what to look for
Long, cylindrical cells with obvious striations (stripes)
Multinucleate cells with the nuclei at the periphery (not in the center)

61. Muscle Tissue: Cardiac
Figure 4.11b

62. Cardiac Muscle

63. Cardiac Muscle: what to look for
Branching, striated cells interlocking at intercalated discs
Uninucleate cells

64. Muscle Tissue: Smooth
Figure 4.11c

65. Muscle Tissue: Smooth
Figure 4.11c

66. Muscle Tissue: Smooth
Sheets of spindle-shaped cells with no striations
Central nuclei

67. Integument

68. Epidermis and dermis

69. Epidermis What to look for:
Usually darkest between stratum germinativum and stratum granulosm (granulosm often a dark meandering line)
Keratinized cells often lift off the section
Melanocytes just below basal lamina

70. Dermis: Papillary vs. Reticular layer

71. What to look for: Papillary layer Reticular layer has ridges
is areolar
Just under basal lamina
Reticular layer
much thicker
Dense irregular CT

72. Again

73. Merocrine sweat gland What to look for: Found in most skin
Coiled, tubular
Small lumens in cross section
Have duct that goes all the way to the epidermal surface and ends in sweat pore
Smaller than apocrine, don’t extend as deep into dermis

74. Apocrine sweat gland

75. Apocrine sweat gland What to look for: Associated with hair follicle
Only in nipples, groin, armpit
Large lumens
Deeper in dermis than merocrine

76. Hair with sebaceous glands and arrector pilli

77. Hair What to look for: Follicles are rarely complete
Can often see root, papilla (at base, wher hair grows)
Arrector pilli muscle at an angle
Associated glands (which are?)

78. Sebaceous glands

79. Sebaceous glands What to look for: Associated with hair follicle
Found most everywhere hair follicles are found in skin
Look like cauliflower (maybe?)

80. Sebaceous follicle

81. Sebaceous follicle What to look for: Also look like cauliflower
Found on face and trunk only
NOT associated with hair follicle
Have duct that opens onto skin surface

82. Random Examples
Can you figure them out?