Quiz Microscopy Flashcards
1
Main switch on/off
2
Brightness adjustment knob
3
Light-path_ selection-knob.
4
Specimen holder
5
Y-axis knob and x-axis knob
6
Revolving nosepiece
7
Coarse focusing knob and fine focusing knob
8
Binocular portion
9
Diopter adjustment rings
Lo
Aperture diaphragm lever
11
Fitter holder (for darker observation)
12
Filter C the filter of 45mm in diameter can be inserted)
Description of the microsvcope.
A microscope is a magnifying glass.
A microscope is a magnifying glass
The compound light microscope ( brightfield microscope) the type use in most clinical laboratories consists of two magnifying lenses:
The objective and the eyespieces (ocular)
The total magnification observed is the product of the magnifications of these two lenses.
Resolving power is the limit of usable magnification.
Resolution indicates how small and how close individual objects ( dots) can be and still be recognizable.
Numerical aperture (NA) is an index or measurement of resolving power.
the light gathering ability of a microscope objective is quantitatively expressed in terms of the NA, which is a measure of the number of highly diffracted image forming light rays captured by the objectgive. Higher NA values allow increasingly oblique rays to enter the objective front lens, producing a more highly resolved image.
Focal length
is the distance from the object being viewed to the lens or the objective.
the magnification and NA are inscribed on each lens as a number.
parts of the mictoscope
Framework
Base
Arm
Stage
Parts of the Microscope
Illumination system components
◦Light source, intensity control, types of bulbs
◦The condenser directs and focuses the beam of light from the bulb onto the material under examination.
◦The aperture iris diaphragm is located at the bottom of the condenser, under the lenses but within the condenser body. By opening or closing the aperture iris diaphragm, you let more or less light into the field of view.
◦A field iris diaphragm is also present in better microscopes.
. Magnification system components
Ocular is the eyepiece, a lens that magnifies the image formed by the objective.
◦Objectives: achromatic and planachromatic,
low-power (10X),
high-power (40X), and
oil-immersion (100X).
◦Objectives are responsible for primary image formation and help determine the quality of images the microscope is capable of producing.
Focusing system
Interocular adjustment, left ocular adjustment, body tube motion: coarse and fine
Passage of Light in Microscope
Lamp condenser
Lens projects an image of the light source onto the plane of the condenser diaphragm.
Ocular lens
The eyepiece magnifies the image created by objective lens a second time and creates an image as if viewed close to the eye.
Objective lens
Gathers light passing through a specimen and projects image into the body tube, the beginning of the magnification process.