L2 - Histology

Question 1

Histology

Answer 1

Study of tissues and organs

Question 2

Cytology

Answer 2

Study of cells

Question 3

Magnification of Light vs Electron Microscope

Answer 3

x1000 vs x1 million

Question 4

Resolution of Light vs Electron Microscope

Answer 4

200 vs 0.2 nm

Question 5

Types of Light vs Electron Microscope

Answer 5

Brightfield, Phase contrast, Fluorescent, Confocal
vs
Scanning, Transmission

Question 6

Resolution

Answer 6

Separation distance at which 2 points can be apart and distinguished as separate

Question 7

TEM features

Answer 7

Electron beam
2D

Question 8

SEM features

Answer 8

Electrons scatter off surface
3D
Lower resolution than TEM

Question 9

Brightfield Features

Answer 9

Stained - enhances contrast, must be fixed
Unstained - Light passes unless naturally pigmented

Question 10

Phase-contrast features

Answer 10

Enhances contrast in unstained by highlighting densities
Live cells

Question 11

Differential interference contrast

Answer 11

Optical modifications to exaggerate different densities

Question 12

Confocal features

Answer 12

Lasers and optics for optical sectioning
Narrow depth of focus
Fluorescently stained specimen

Question 13

Fluorescence features

Answer 13

Show location of molecules in cells by absorbing short wavelength and emitting long

Question 14

Histology Order of processes

Answer 14

Fixation
Dehydration
Embedding
Sectioning
Staining
Pathologist review and report

Question 15

Fixation

Answer 15

Commonly formaldehyde and glutaraldehyde or alcohol
Arrests activity, prevents degradation, amenable to staining

Question 16

Dehydration

Answer 16

Remove water to prevent tissue damage

Question 17

Embedding

Answer 17

Support by embedding in hard medium
Causes artefacts

Question 18

Sectioning

Answer 18

Cryostat
Microtome
Vibratome

Question 19

Cryostat

Answer 19

-10 - 20C
10 - 40 microns
On slides or free floating

Question 20

Microtome

Answer 20

Embed in wax (rtp)
5 - 40 microns
On slides

Question 21

Vibratome

Answer 21

Glue to holder (rtp or less)
40 - 400 microns
Slides or free floating

Question 22

Stained

Answer 22

Haematoxylin - Acidic = purplish blue
Eosin - basic structures = red/pink
Giemsa
Toluidine blue
Masson’s trichrome
Periodic acid

Question 23

Immunochemistry

Answer 23

Antibiotics used to label proteins or cells

Question 24

Adenoma

Answer 24

Benign neoplasia derived from epithelial cells

Question 25

Carcinoma

Answer 25

Malignant neoplasia derived from epithelial cells