Microscopy Flashcards
Describe what microscopy is
Microscopy is the science of using microscopes to view small objects that cannot be seen with the naked eye, such as cells, tissues, and microorganisms.
Identify the two main types of microscopes
Light microscope and electron microscope.
Explain how a light microscope works
A light microscope uses visible light to illuminate a specimen. The light passes through the specimen, is magnified by the objective lens, and further magnified by the eyepiece lens, allowing the observer to see the image.
State the maximum magnification and resolution of a light microscope
The magnification is up to 1000x, and the resolution is limited to ~200 nm.
Give examples of specimens suitable for observation with a light microscope
Live cells, bacteria, and simple tissues.
Explain why stains are used in light microscopy
Stains are used to improve contrast and highlight specific structures within cells or tissues, making them easier to see under the microscope.
List three stains and their effects
Methylene Blue: Stains nuclei blue.
Leishman’s Stain: Stains blood cells pink and white blood cell nuclei blue.
Hematoxylin/Eosin: Stains nuclei blue and cytoplasm pink.
Calculate the total magnification if the objective lens is 40x and the eyepiece lens in 10x
Total magnification = 40x × 10x = 400x.
Describe the function of the condenser in a light microscope
The condenser focuses light from the illuminator onto the specimen, ensuring even illumination and better image quality.
Explain the role of the iris diaphragm
The iris diaphragm controls the amount of light reaching the specimen, which affects the contrast and brightness of the image.
Distinguish between the functions of the coarse focus knob and fine focus knob
The coarse focus knob brings the specimen into general focus, while the fine focus knob adjusts the image precisely, especially at higher magnifications.
Outline the steps involved in specimen preparation for light microscopy
The steps include fixation, dehydration, clearing, embedding, sectioning, staining, and mounting.
Describe the purpose of fixation in specimen preparation
Fixation preserves the specimen in a life-like condition with minimal distortion, making it suitable for examination.
Explain why sectioning is important in microscopy
Sectioning produces thin slices of the specimen, allowing light to pass through, which is necessary for clear visualization under the microscope.
State the formula for calculating magnification
Magnification = Image size / Actual size of the specimen.
Describe how a light microscope is used to observe a blood sample
A blood sample is placed on a glass slide, stained to highlight specific structures (e.g., Leishman’s stain), and then observed under a light microscope. The light passes through the sample, which is magnified by the objective and eyepiece lenses, allowing detailed visualization of blood cells.
Explain the importance of staining in light microscopy when examining tissues
Staining increases contrast, making specific structures (e.g., nuclei or cytoplasm) more visible. This allows for better identification of cell components and any abnormalities, which aids in diagnosis and research.
Identify the part of the microscope responsible for adjusting the amount of light reaching the specimen
The iris diaphragm
Explain why using a blue light filter can improve resolution in a light microscope
blue light has a shorter wavelength than white light, allowing for finer resolution and greater detail in the observed image.
Explain how microscopy can aid in diagnosing diseases
Microscopy allows for the observation of cells and tissues at a microscopic level. Abnormalities, such as changes in cell size, shape, or structure, can indicate diseases like cancer or infections.
Identify two advantages of using a light microscope in healthcare
- It allows for the observation of live specimens, enabling dynamic studies of cell behavior.
- It is cost-effective and widely available, making it accessible for routine clinical use.
Explain how staining blood samples can help in diagnosing anemia
Staining allows for the identification of red blood cells’ size, shape, and count. Abnormalities, such as smaller or fewer red blood cells, can indicate anemia.
Outline how a health professional might prepare a tissue sample for microscopic examination
1.Fixation: Preserve the tissue.
2.Dehydration: Remove water.
3.Clearing: Make tissue transparent.
4.Embedding: Support for cutting.
5.Sectioning: Cut thin slices.
6.Staining: Enhance contrast.
7.Mounting: Protect for viewing.
