Basics

Question 1

Define tissue

Answer 1

A collection of cells specialised to perform a particular function

Question 2

What are the 4 types of tissue classification?

Answer 2

epithelial, connective, muscle and nervous

Question 3

Name the 7 systems of the human body

Answer 3

musclo-skeletal, cardiovascular, respiratory, genitourinary, gastro-intestinal, nervous and reproductive

Question 4

What is micrometers in metres?

Answer 4

10^(-6) m

Question 5

What is the diameter of a red blood cell?

Answer 5

7.2 micrometers

Question 6

Define biopsy

Answer 6

The removal of a small piece of tissue from an organ or part of the body for microscopic examination.

Question 7

Name the 6 types of biopsy and give an example of where each one would be used

Answer 7

Smear  eg. cervix
Curettage   eg. uterus 
Needle    eg. brain/muscle
Direct Incision  eg. skin
Endoscopic   eg. intestine
Transvascular  eg. heart

Question 8

What is a microtome?

Answer 8

A machine that cuts specimens embedded in wax into thin slices that we can view under a microscope

Question 9

Why do biopsies need to be fixed?

Answer 9

To prevent autolysis and kill any bacteria

Question 10

Name the 2 reagents used for fixing biopsies

Answer 10

Glutaraldehyde

Formaldehyde

Question 11

What are the 3 steps a fixed biopsy most go through to be embedded in wax?

Answer 11

dehydration (ethanol)
cleaning (xylene)
embedding (56 degrees celsius)

Question 12

Which stains are most widely used?

Answer 12

Haematoxylin and Eosin

Question 13

What does haematoxylin stain and what colour?

Answer 13

stains acidic components of the cells purple

eg. nucleolus/chromatin

Question 14

What does eosin stain and what colour?

Answer 14

Stains basic components of the cells pink

eg. cytoplasmic proteins

Question 15

What does Periodic-Acid-Schiff stain and what colour?

Answer 15

stains carbohydrates and glycoproteins magenta

eg. mucus and basement membranes

Question 16

How does contrast microscopy work?

Answer 16

It exploits the interference effects produced when 2 sets of waves combine: used to see detail in living cells

Question 17

What is different about darkfield microscopy?

Answer 17

The light comes from the side not underneath

Question 18

What is confocal microscopy?

Answer 18

The imaging of tissues which have been labelled with one or more fluorescent probes. The confocal microscope eliminates the ‘out-of-focus’ flare from the specimens. Illumination is achieved by scanning one or more beams of light across the specimen. This imagining can be used to construct 3D images.

Question 19

Define histology

Answer 19

The study of the structure of tissues by means of special staining techniques combined with light and electron microscopy.