Foundations of Histology

Question 1

field diaphragm

Answer 1

closing the diaphram limits the size of the illuminated field on the stage of the microscope

Question 2

substage condenser

Answer 2

can be up and down - move until outline of field diaphragm is sharp

Question 3

Koehler illumination steps

Answer 3

1. bring the field into focus at 10x
2. open numerical aperture
3. close the field diaphragm
4. adjust height of condenser
5. adjust the circle of light
6. center the circle of light
7. open the diaphragm
8. set the numerical apterture

Question 4

(Fixation) preservation

Answer 4

prevents autolysis and decomposition

Question 5

(Fixation) stabilization

Answer 5

maintains the proper relationship between cells and extracellular substances

Question 6

(Fixation) stabilization of proteins

Answer 6

inactivates enzymes

Question 7

(Fixation) visibility

Answer 7

brings out differences in refraction index and increases the contrast between different tissue elements

Question 8

positives of fixation

Answer 8

preservation
stability
stability of proteins
visibility
enhances staining
hardens tissue for cutting
devitalizes/ inactivates infectious agents
tissue more receptive to dyes

Question 9

affect the quality of fixation

Answer 9

temp
size of tissue
volume ratio (at least 1:10)
choice of fixative
time of fixation
penetration rate
pH and osmolality

Question 10

fixation drawbacks

Answer 10

alters proteins
loss of soluble tissues (lipid and glycogen)
tissue shrinkage
DNA/RNA degradation

Question 11

Things that negatively impact fixation

Answer 11

container size to small
not received with fixative
time in fixative
tissue placed in something bad

Question 12

Duke fixatives

Answer 12

Formalin
Glutaraldehyde

Question 13

other fixatives than Dukes

Answer 13

zinc formalin
alcohols

Question 14

other solutions

Answer 14

immunofixative - micheals, zeus
RPMI- for cytogenetics
Decalcifiers- EDTA(immunocal), nitracal, HCl

Question 15

keep small tissue safe

Answer 15

embedding bags
microcassettes
filter paper
sponges
agar

Question 16

automated processor

Answer 16

deydrates tissue through alcohols
cleans tissue w xylene
infiltrates tissue with paraffin

Question 17

embedding skin

Answer 17

epidermis face one side of mold

Question 18

embedding tubular structures

Answer 18

cross section face down

Question 19

embedding structure with a wall

Answer 19

on edge with all layers visible

Question 20

embedding bone

Answer 20

diagonally

Question 21

H&E stain

Answer 21

xylene, alcohols and water, hematoxylin, bluing, eosin, alcohol, xylene, coverslip

Question 22

immunochemistry

Answer 22

antigen antibody interactions
detects antigens on tissue sections

Question 23

IHC needed for

Answer 23

tumor classification
determining in situ vs invasion
prognosis
guide therapy
identify extracellular material
see infectious agents

Question 24

CMV

Answer 24

cytomegalovirus in immunosuppressed patients

Question 25

ADV

Answer 25

adenovirus on small and large bowel in immunosuppressed pediatric patients

Question 26

HP

Answer 26

h pylori on gastric antral biopsy

Question 27

EBNA2 and LMP 1

Answer 27

ebstein bar virus for EBVrelated tumors and some selected immunosuppressed patients

Question 28

calretinen

Answer 28

hirschprungs disease

Question 29

prosessing problems

Answer 29

fat, thick sections, calcified tissue, hair and keratinous material, foreign, floaters, unclear orientation, missing tissue, block missing, incorrectly labeled/wrong block