Microscopy Basics: Tissue ID - Anatomy and Physiology
- The field of view is 4.0 mm wide at 40x total magnification. About how wide is it at 400x?
- About 0.4 mm. Field diameter is inversely proportional to magnification, so 10 times the magnification gives one tenth the width.
- A tissue shows large, empty-looking cells with the nucleus pushed to one edge like a signet ring. What tissue is it?
- Adipose tissue. Fat dissolved during slide preparation leaves the large vacuole looking empty.
- A single layer of ciliated cells has nuclei at different heights, so it looks layered. What tissue is it?
- Pseudostratified ciliated columnar epithelium. Every cell touches the basement membrane, but not all reach the surface.
- In an H&E stained section, what color do most cytoplasm and collagen fibers appear?
- Pink. Eosin binds basic proteins in the cytoplasm and extracellular fibers (acidophilic).
- A compound microscope has a 10x ocular lens and a 40x objective lens. What is the total magnification?
- 400x. Total magnification is ocular magnification times objective magnification.
- Which objective lens should be used first when locating a specimen on a slide?
- The lowest-power (scanning) objective, because it has the widest field of view and the greatest working distance.
- A tissue shows cells sitting in small cavities within a smooth, glassy matrix with no visible fibers. What tissue is it?
- Hyaline cartilage. The cells are chondrocytes in lacunae, and its fine collagen fibers are not visible.
- A tissue shows concentric rings of matrix around a central canal. What tissue is it?
- Compact bone. Each ring system is an osteon, with lamellae surrounding a central canal.
- Why should only the fine adjustment knob be used with the high-power objective?
- The working distance is very small, so the coarse knob could drive the objective into the slide and damage both.
- What is the approximate best resolution of a standard light microscope?
- About 0.2 micrometers. Structures closer together than this cannot be seen as separate.
- A slide with the printed letter e is placed right side up on the stage. How does it appear through a compound light microscope?
- Upside down and reversed (inverted), because the lenses invert the image.
- In an H&E stained section, what color are nuclei, and why?
- Blue to purple. Hematoxylin binds acidic structures such as DNA in the nucleus (basophilic).