Ch 1: Overview of Methods Used in Histology

Question 1

Histology

Answer 1

the scientific study of microscopic structures of tissues and organs of the body

Question 2

Histopathology

Answer 2

microscopic study of diseased tissue

Question 3

Histotechnology

Answer 3

processing of tissues in such a manner as to enable microscopy/ study of the tissue

Question 4

What are the 7 steps to prepare a slide?

Answer 4

Fixation, Dehydration, Embedding, Sectioning, Mounting, Staining, Observation

Question 5

Fixation

Answer 5

Purpose: Maintenance of tissue architecture by cross linking proteins and inhibiting autolysis

Question 6

Dehydration & Clearing

Answer 6

Purpose: To remove all the water because the Paraffin ( embedding medium) is immiscible in water. Clearing involves removing the alcohol and replacing it with a chemical that is miscible in both alcohol and paraffin.

Question 7

Embedding

Answer 7

Tissues are then placed in an oven containing liquid Paraffin that “ Infiltrates” it

Question 8

Sectioning

Answer 8

involves using a machine called a microtome that cuts sections very thinly in the form of ribbons

Question 9

Mounting & Staining

Answer 9

Mounting: the thin sections obtained from the mocrotome are mounted upon glass slides
Staining: the most common stains are Hematoxylin and Eosin

Question 10

Hematoxylin

Answer 10

Is a basic dye that colors the acidic components of cells giving them a bluish-purple tint

Question 11

Eosin

Answer 11

Is an acidic dye that colors the basic components of cells giving them a pinkish tint

Question 12

Metachromasia

Answer 12

Absorbs certain wavelength of light and emit different wavelength. Polyanions of tissues bind with dye molecules result in polymer or dimers of dye molecules