Parts of the Microscope Flashcards
These are the 3 main structural part of the microscope.
Head, Arms, Base
Contains the microscopic illuminator
Base
Contains optical components such as the eyepiece and objective lenses.
Head
Connects the base to the head and supports the eyepiece tube. It’s where you carry the microscope.
Arms
Turns the lamp on and off
Power switch
Consists of a lamp bulb and one or more lenses to produce a cylindrical beam of light directed toward the base of the condenser. May have a ground glass and may have an iris or field diaphragm.
Illuminator
Controls the brightness of the lamp. On most microscopes it is a continuously variable rheostat, controlled by a sliding
switch
Illumination control
A frosted sheet of glass that scatters the light from the lamp bulb to provide more diffuse light.
Ground glass
Controls the diameter of the illuminating beam of light as a guide to focus the light from the condenser onto the specimen.
Iris Diaphragm
Contains a set of lenses that focus the light on the specimen.
Condenser
The condenser has the following components:
- Focusing knob
- Front lens
- Iris Diaphragm
The glass surface closest to the specimen. Be careful not to touch this
surface as it is easily scratched
Front lens
Controls the aperture of the illuminating light and used to adjust contrast.
Iris diaphragm
Moves the condenser up and down to adjust the focus of the light on the specimen
Focusing knob
Holds several objective lenses that can be rotated into position to change the lens
Revolving nosepiece
Create a magnified image of the specimen.
Objective lenses
There are 4 types of objective lenses:
- Scanning Lens
- LPO
- HPO
- OIO
Used to get an overview of the structures present in a section and to find areas for more detailed observation.
Scanning lens
The most useful magnification to identify tissues
Low Power Objective (LPO) 10x lens
Used to see the details of cell and tissue organization.
High Power Objective (HPO) 40x lens
Because it requires the use of immersion oil, is used primarily to see subcellular details.
Oil Immersion Objective (OIO) 100x lens
Forms an image that can be visualized by the eye or a camera. In a binocular
microscope, the distance between the two tubes can be adjusted to fit the distance between the observers’ eyes.
Eyepiece
Used to raise and lower the specimen stage to focus the image of the specimen. It consists of the coarse and fine focus.
Focusing controls
Used to focus the specimen at 4x and 10x
Coarse focus
Used to focus the specimen at 40x and 100x, but only after initially focusing at lower magnification.
Fine focus
Holds the microscope slide. Consists of the slide holder and slide holder travel controls.
Specimen stage
Spring-loaded device to hold the microscope slide in place on the stage.
Slide holder
Allow the slide to be moved along two axes: longitudinal and lateral.
Slide holder travel controls
The total magnification for the microscope is obtained by multiplying the:
Magnification of the eyepiece and magnification of the objective lens
___ is the ability to enlarge an image (what you see looking through the eyepiece).
Magnification
___ might be monocular or binocular.
Ocular lenses
Ocular lens may be ___, ___, ___.
5x, 10x or 30x
The area your lens can see; the actual “circle” you see. The circular area will ___ as you increase the magnification.
Field of view, decrease
The thickness of the vertical range in which the specimen remains in focus. It decreases as the magnification ___.
Depth of focus, increases
- Light illuminated
- Image is 2D
- High magnification, low resolution
- Mechanic focusing
- Good for transparent or translucent specimens
Compound microscope
- Light illuminated
- Provides 3D image of specimens
- Low magnification (5x - 10x)
- Mechanical focusing
Dissection Microscope
- Uses electron illumination
- 3d view of image
- High magnification, high resolution
- Electrical focusing
Scanning Electron Microscopy (SEM)
- Uses electron illumination
- 2d view (internal structures)
- High magnification, high resolution
- Electrical focusing
Transmission Electron Microscopy (TEM)
___ have shorter wavelengths than light.
Electrons