Histology Exam 1

72 flashcards · Biology · by Jared Blackwell

1. What do you see at Low, Intermediate, High power?

   Low power - no individualized cells. Intermediate- tissue organization High Power- cellular/nuclear detail.

2. Describe difference between Light Microscopy, EM, and scanning.

   Photons of light pass through, colored. Focused by glass lenses. Maximum resolving power is 0.2 micrometers. TEM displays internal structure, black & white. TEM max resolving power is 3nm. Electron beam wavelength shorter. Scanning- 3D image. External image.

3. Base or Acid Stain?

   Base stain.

4. What do base stains display? What do acid display?

   -Stains blue/purple. -Organic acids, nucleic acids (RNA/DNA), negatively charged molecules. -Pink red color -Collagen fibers, cytoplasmic proteins, membrane proteins and mitochondria.

5. Base or Acid Stain?

   Acid stain.

6. What stain is this?

   -Trichome stain. -Stains collagen fibers blue/green.

7. What stain is this?

   -PAS stain. -Stains carbohydrates rich structures magenta.

8. What stain is this?

   -Silver stain. -Stains glycosylated reticular fibers black.

9. What stain is this?

   -Orcein stain. -Stains elastic fibers black/brown.

10. What stain is this?

    -Sudan red. -Stain lipids red.

11. What stain is this?

    -Osmic acid. -Stains lipids black.

12. Are plasma membranes acidophilic or basophilic?

    -Plasma membranes are acidophilic.

13. Hydrophilic is _____? Hydrophobic is ______?

    Hydrophilic is electron dense. Hydrophobic is electron lucent.

14. Distinguish between E-face and P-face. Which side is glycocalyx on?

    E-face is outer leaflet facing Extracellular side. Glycocalyx on E-face. P-face is inner leaflet facing cytoPlasmic side.

15. What is the difference between Constitutive and Regulated secretion (exocytosis)?

    Constitutive secretion is continuous. NO accumulation of vesicles. NO additional signaling. Regulated secretion has an accumulation of vesicles that congregate near PM. Vesicles condense into secretory granules. Requires special stimulus.

16. Is this Constitutive or Regulated secretion and why?

    Constitutive because there is few to no secretory granules present.

17. Is this Constitutive or Regulated secretion and why?

    Regulated secretion due to presence of secretory granules.

18. What are the blue arrows pointing to? What type of endocytosis is this and explain what it entails?

    -Pinocytotic vesicles (caveolae). -Pinocytosis is generalized for ALL cells. They form pinocytotic vesicles - caveolae. Water and small solutes. "Cell drinking."

19. What are the blue lines pointing to and what are their function?

    Pseudopodia that extend and surround material in phagocytosis.

20. What are the four steps in Phagocytosis?

    Pseudopodia extend to surround material Vesicles called phagosomes are formed. Lysosomes fuse with phagosome (phagolysosome). Breakdown of material occurs in phagolysosome.

21. Is electron density even in phagolysosome?

    -Uneven

22. Receptor-Mediated endocytosis is

    Highly selective.

23. What is the yellow and white pointing to? What are their functions?

    Yellow- Nuclear envelope. Inner/outer membrane. White- Nucleolus, makes rRNA & ribosomal subunits. Zoomed in:

24. Difference between Euchromatin and Heterochromatin?

    Eucharomatin is the active part of genome. DNA is uncoiled to code proteins. Electron lucent. Heterochromatin is condensed and less active. More electron dense.

25. What is this an image of, also label blue and purple points?

    Image of a nucleus. Blue- Euchromatin, uncoiled (electron lucent). Purple- Heterochromatin, dense, electron dense.

26. If you see an abundance of euchromatin and nuclei what does this suggest?

    This suggests very active protein synthesis.

27. What are the two arrows pointing to and their functions?

    Left arrow- Free ribosomes which create cytoplasmic proteins. Right arrow- ER-bound ribosomes which create membrane proteins, secretory proteins, and lysosomal proteins.

28. Are ribosomes acidophilic or basophilic?

    Ribosomes are basophilic due to rich in acidic compounds like rRNA.

29. What does a basophilic cytoplasm suggest?

    It suggests the cytoplasm is ribosome rich.

30. What is the blue and white arrows pointing to?

    Blue arrow- Outer surface ER bound ribosomes. White arrow- Inner lumen, cisterna.

31. Fill in the Blank: Proteins are synthesized into the _______, then transported to the ________ for modification and packaging.

    Cisterna Golgi

32. What is this a picture of?

    Golgi. NO ribosomes.

33. How does the Golgi look under LM?

    Under LM golgi is pale "negative golgi"

34. What is this a picture of? What are the yellow arrows pointing to?

    Mitochondria. Yellow pointing to cristae.

35. What are arrows pointing to?

    Lysosomes which have uneven electron densities.

36. What is the top and bottom arrow pointing to?

    Top: rER Bottom: sER

37. Describe Actin

    -Smallest diameter of cytoskeletons. -Form core of microvilli. -Extend pseudopodia for phagocytosis. -Movement e.g. contraction of myosin. -Anchor cells to ECM.

38. Describe Microtubule

    -Largest of cytoskeletons. -Shrink and grow similar to actin. -Use cilia for movement. -Intracellular transport. -Maintain cell shape -9 doublet + 2 central microtubules - found in cilia.

39. Label each color

    Blue - epithelium Yellow - muscle Green - Connective tissue Light Blue - Nervous tissue

40. Difference between parenchyma and stroma?

    Parenchyma - functional tissue. Stroma - supporting tissue.

41. Characteristics of Epithelium

    -Avascular -Have polarity (intracellular orientation) -Capable renewal -Cells adhered by intercellular junctions.

42. Label each structure

    Blue- Apical domain Yellow- Lateral domain Red- Basal Domain

43. What is arrow pointing to?

    Lateral Domain

44. Where are lateral infoldings abundant in?

    Cells that specialize in fluid transport e.g. kidney, gallbladder.

45. What is this and its function?

    Tight junctions. -Restrictive seal between cells. Adheres plasma membrane of adjacent cells.

46. Adheren junction. -resist mechanical separation. CAMs link to actin cytoskeleton. -No direct contact with plasma membrane. uniform separation.

47. Desmosome -resists mechanical separation. CAMs link to intermedaite filaments at attachment plaques. electron-dense discs.

48. Gap Junction -signaling between cells. Conformational changes in connexon open and close channels. -Under EM electron-lucent region

49. Microvilli

50. What is the light gray shown on outside?

    Glycocalyx.

51. Cilia. 3-4x longer than microvili and less uniform. Specialized to propel material.

52. Difference between cilia and microvilli core?

    Cilia core comprised of microtubules: 9 doublets and 2 singlets. Anchored to basal body. Microvilli core comprised of Actin linked to terminal web.

53. Describe the Basement Membrane. Function, type of stain?

    -LM term -Basal lamina (dense) + reticular lamina (diffuse). -Site of cell-to-ECM adhension and exchange with connective tissue. Acts as selective macromolecule filter. -Anchored by epithelium and CT. -Anchoring site for epithelial cells.

54. Describe basal lamina

    -anchors epithelium to CT, provides polarity. -form scaffold for epithelial tissue growth & regeneration (proteoglycans secreted by epithelial cells). -Regulates movement of molecules to/from CT.

55. What do fibrils do?

    Fibrils anchor basal lamina to reticular lamina (secreted by CT cells).

56. Function of hemidesmosomes?

    Hemidesmosomes anchor intermediate filaments to basal lamina.

57. Name each dot/arrow

    -Epithelial cell -Basal lamina -Reticular lamina -fibrils -Reticular fibers

58. Function of focal adhesions?

    Focal adhesions anchor actin cytoskeleton to basal lamina.

59. Name each

    -Simple squamous -Simple cuboidal -Simple Columnar.

60. Label

    White arrow is goblet cell, no cilia, secretes mucus. Yellow - basal cell, stem cell.

61. Transitional epithelium, 6 layers. -Stratified epithelium that forms a distensible barrier in urinary system.

62. Explain Metaplasia

    Epithelial metaplasia is differentiation of one type of mature epithelium into another due to chronic inflammation or physical/chemical irritation. -e.g. stratified squamous to simple columnar.

63. What type of cells are these?

    Left is serous and right is mucus secreting exocrine gland. Serous exocrine glands have rounder nucleus and dark-staining secretory granules. Mucus exocrine glands have darker, flatter nucleus with pale secretory granules.

64. What is the structure of Elastic Fibers?

    Has an Elastin Core and Fibrillin Microfibrils.

65. Steps of Collagen Assembly

    Begin as 1. Tropocollagen molecules and form a triple helix. 2. Fibrils will have dark and light regions. Sometimes they will then form 3. Fibers. The fibers can form a 4. Fiber Bundles. -Collagen fibrils exhibit 68nm periodicity.

66. Type I Collagen

    90% of collagen in body. Bone, ligaments, tendons, dermis, scar tissue, sclera of eye. Strong tensile strength. Gross level appearance is white. H&E stain are pink because proteins. Trichome stain blue/green. Osteogenesis imperfecta "brittle bone disease." Multiple fractures with minor trauma.

67. Type II Collagen

    Makes up Cartilage and vitreous body of eye. Resists pressure, accumulates fluid constrains proteoglycan aggregates. . NO fiber bundles. Forms a "chicken wire" thin-line appearance. Can see periodicity at high magnification due to fibrils. Very negatively charged and draws water into it, very hydrated. Achondroplasia is defect in Type II collagen, defect in growth plate.

68. Type III Collagen "Reticular Fibers"

    Remains only as Fibrils. Heavily glycosylated. Supports dermis, internal organs, and blood vessels. Defect in Type III produces flexible skin, easy bruising, early mortaility due to rupture of blood vessels and internal organs. Ehlers-Danlos Syndrome. NO H&E stain because they are glycosylated. Use Silver stain - black reticular fibers and PAS - magenta carb-rich.

69. Type IV Collagen

    Sheet forming Collagen. NO fibrils. In Basal lamina. Filters between epithelial cells and CT. Underneath basal lamina is Reticular fibers aka Type III collagen.

70. Ground Substance

    Appear empty....

71. GAGs

    Chain of high negatively charged molecules attached to central protein with entire structure being the Proteoglycan. More GAGs you put together, more negative charge. Furthermore, more Preoteglycans in aggregate more negative charge which brings in water. Stain with basic stains and PAS stain.

72. Multiadhesive Glycoproteins

    Stabilize the ECM and bind cells to ECM. Go through cytoskeleton.