Practicals

Question 1

Types of microscopes

Answer 1

• Single
• Compound
• Fluorescent
• Electron

Question 2

Single Microscope

Answer 2

is used to produce an enlarged image of an object placed within its focal length -> single lens

Uses: very limited and observational

Advantages: quick observation

Limitations: very low resolution

Question 3

Compound Microscope

Answer 3

there are 3 to 5 lenses, which magnification is combined.

Uses: the most used fro diagnostic purposes

Advantages: reduced chromatic aberration and increased magnification power

Limitations: resolution

Question 4

Fluorescent Microscope

Answer 4

a structure of interest is labelled with a fluorescent probe.
It is illuminated with light of a specific wavelength which is absorbed by the fluorophore contained in the probe.

Uses: for research purpose

Limitations: photobleaching autofluorescence

Question 5

Electron Microscope

Answer 5

uses a beam of accelerated electrons as a source of illumination.

Uses: investigation of the ultrastructure of a wide range of biological and inorganic specimens.

Advantages: no require molecular knowledge of the specimen under investigation, very high-resolution power.

Limitations: Expensive and laborious

Question 6

Cytology: what is it and why is important

Answer 6

Cytology is commonly used to investigate abnormal tissues.

Samples can be taken rapidly using a needle and without the use of anaesthetic.

Tissues vary in the amount of cells you can obtain and that determinate its usefulness for diagnosis.

Question 7

Advantages of Cytology

Answer 7

1. Samples can be taken rapidly
2. May be used fro both solid tissue and fluids
3. Costs are reduced

Question 8

Limitations of Cytology

Answer 8

1. insufficient cells are harvested to allow a confident diagnosis
2. tissue examination is needed to establish the origin of the cells

Question 9

Discrete (round) Cells

Answer 9

are usually abundant in cytology samples and have well preserved morphology.

Examples:
- histiocytes
- lymphocytes
- mast cells

Descriptions:
round or oval shape, well-defined cytoplasmic borders, appear as individual cells

Question 10

Epithelial Cells

Answer 10

usually exfoliate well.

Description: round to polygonal to columnar shape, often grouped in tight clumps or sheets

Question 11

Mesenchymal Cells

Answer 11

exfoliate less well.

Examples:
- Skeletal muscle
- Tendons

Description:
cells have spindle or stellate shapeL; cytoplasmic borders are usually less well-defined; cells are arranged individually or grouped in clumps.