Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology 2 > Histology: Specimen to Slide > Flashcards

Histology: Specimen to Slide Flashcards

1
Q

What do you put a histology sample in at collection?

A

10% neutral buffered formalin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is it important to put tissue is a fixative after it’s collected?

A

Prevents autolysis and other changes, helps with staining and allows for better contrast between tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the minimum ratio for formalin to tissue?

A

10:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

At what rate does formalin fix tissues?

A

~1mm/hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the minimum time required for fixation in 10% NBF?

A

At least 24 hours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What other fixatives can you use to harden autolysed and neural tissues?

A

Bouin’s or Davidson’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What tissues can you use Bouin’s or Davidson’s to fix?

A

Autolysed tissues, neural tissue, eyes, fetal tissue, and uterine biopsies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What should you do if the sample is really bloody or contaminated with lots of organic material?

A

Change the formalin after 24 hours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If the tissues is very large, what should be done to help ensure fixation throughout?

A

Breadloaf or cut the tissues into slices no thicker than 1 cm to let the fixative penetrate more effectively.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What should you include in a tissue sample?

A

Both the lesion and normal tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What should you include in a sample of tissue without an obvious lesion?

A

All tissue layers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What should the surgeon do with masses requiring a margin assessment?

A

Mark the orientation with something like suture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What should the histology technician do with masses that require a margin assessment before trimming do?

A

Ink the mass.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the ideal thickness of a tissue?

A

3mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What special step is required with bone samples?

A

Bone must fix for 24 hours and then be exposed to a decalcifier until it’s demineralized (can take up to a week).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What special step is required with keratinized samples (eg. hoof or nail)?

A

Must be softened.

17
Q

What is the basic concept of processing?

A

To replace the tissue’s water with wax.

18
Q

What is the purpose of the graded alcohols during processing?

A

Alcohol replaces the water to prepare the sample for the next step.

19
Q

What is used during processing after the graded alcohol treatment?

A

Xylene, which replaces the alcohol in preparation for the next step.

20
Q

What is uses during processing after the Xylene treatment?

A

Parafin, which replaces the Xylene.

21
Q

What is the purpose of a processor?

A

It exposes the tissues to each solution (alcohol, Xylene, parafin) for the appropriate amount of time.

22
Q

What aids the processor in its process?

A

Vacuum and pressure which help the solution penetrate the tissue.

23
Q

What is embedding?

A

Creates a tissue block by adding paraffin around the treated tissue sample.

24
Q

What is a microtome?

A

Used to cut the paraffin embedded tissues.

25
Q

What is rough trimming?

A

Exposing the tissue, by cutting off the excess paraffin at 5-30um until the whole surface of the tissue is exposed.

26
Q

What is a key step to help make cutting of the block easier?

A

ICE!

NOTE: If tissue is very friable, may need to sit on ice all day.

27
Q

How thick are most cuts?

A

4um

28
Q

How thick are the cuts for a sample that will be stained with Congo red?

A

Closer to 10um.

29
Q

How thick are the cuts for a melanoma?

A

Closer to 2um.

30
Q

Why is the ribbon floated?

A

The water is a little lower than the melting point of the paraffin, so it helps to smooth out the sample.

31
Q

What must happen prior to staining?

A

The slide is heated at ~60 degrees Celcius for 40 minutes to make sure it’s dry and the tissue is adhered to the slide.

32
Q

What is the first step in staining?

A

The slides need to be deparaffinized.

33
Q

How do you deparaffinize a slide?

A

Opposite to how we added the paraffin (Xylene bath > graded alcohols > water).

34
Q

What stain is the first stain used for diagnostic interpretation?

A

H&E (Hematoxylin and Eosin)

35
Q

What is coverslipping?

A

After staining, slides are dehydrated (graded alcohols and then Xylene), then a mounting medium is applied that is miscible with xylene and the coverslip is applied.

36
Q

What is the clearing agent?

A

Xylene.

Pathology 2 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions