Histology and its Methods of Study

Question 1

Two types of electron microscopes

Answer 1

transmission, scanning

Question 2

9 steps in slide preparation

Answer 2

1) tissues are obtained and cleaned 2) chemically fixed 3) processed (dehydrated and cleared) 4) embedded in paraffin 5) sectioned with a microtome 6) mounted on a slide 7) de-paraffinized and rehydrated 8) stained 9) coverslipped

Question 3

3 types of fixatives

Answer 3

1) aldehydes 2) alcohols 3) oxidizing agents ex/ KMnO4

Question 4

how is a slide processed after being fixed?

Answer 4

1) dehydrated via alcohol exposure 2) alcohol is replaced with xylene 3) slide is infiltrated with paraffin embedding agent

Question 5

how is a slide rehydrated after being mounted?

Answer 5

-opposite order of dehydrating! 1) remove the paraffin 2) expose slide to xylene 3) replace xylene with alcohol 4) replace alcohol with water

Question 6

toluidine blue, hematoxylin and methylene blue are all examples of ____ stains

Answer 6

BASIC STAINS

Question 7

Orange G, eosin and fuchsin are all examples of ___ stains

Answer 7

ACIDIC stains

Question 8

Osmium tetroxide is good at visualizing:

Answer 8

adipose and fatty substances

Question 9

What kind of stain was used for this?

Answer 9

Osmium Tetroxde: good at visualizing fat droplets

Question 10

What tissue type is this (left)? What are the two layers called (left pic)? What kind of stain was used to visualize this?

What kind of stain was used on the right? What kind of structures is this stain good at differentiating?

Answer 10

Left: Muscle tissue (smooth) with two layers; an outer longitudinal and an inner circular layer that allows it to move in graded fashion/peristaltic manner. Normal Hemotoxylin and Eosin stain used

Right: also muscle tissue. This time, TRICHROME STAIN was also used. Differentiates between collagenous fibers and basophilic structurs, allows you to see the connective tissues that attah fasciles together. Ex/ paramycium ,endomycium etc.

Question 11

What kind of stain is used here? What type of tissue is this?

Answer 11

This is nervous tissue. SILVER stain used

Question 12

Name and purpose of this staining? What does it have affinity for?

Answer 12

Periodic Acid-Schiff stain (PAS). Good for visualizing microvilli brush boarder and goblet cells. Often counter stained with hemotoxylin. Also has high affinity for GLYCOPROTEINS

Question 13

What kind of stain is used here? Purpose?

Answer 13

Giesma stain. Good for visualizing white blood cells and general blood components. Differentiates cytoplasms, granules, and nuclei of cells

Question 14

What is immunihitochemistry?

Answer 14

Specific interactions between lantibody and antigen to allow precise identification, localization, and in some cases, quantification of cellular components (usually proteins)

Question 15

Examples of cellular inclusions

Answer 15

fat droplets, glycogen granules, lipofuschin pigment

Question 16

List other histological techniques that allow for visualization in addition to staining

Answer 16

1) immunohistochemistry
2) frozen sections: freezing sections in liquid nitrogen for fast cutting and staining. Good when you need to know histo results ASAp
3) electron microscopy tissue prep: fized with osium and embedded in plastic rather than paraffin. Allows for embedding of thinner sections.

Question 17

Hemotozylin has affinity for ___ acids, and eosin is an ___ dye with an affinity for ___ cytoplasmic components of the cell.

Answer 17

Hemotozylin has affinity for NUCLEIC acids, and eosin is an ACIDIC dye with an affinity for BASIC cytoplasmic components of the cell.

Question 18

The golgi method is a specific type of ___ staining that specifically brings out ___

Answer 18

specific type of silver staining that brings out PYRAMEDAL NEURONS