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30 Cards in this Set
- Front
- Back
Compound Microscope |
Precision instrument where the magnification is achieved through the interplay of two lenses - the ocular and objective. |
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Objective lens |
Magnifies the specimen to produce a real image that is projected to the ocular. |
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Ocular lens |
Magnifies the real image to produce the virtual image that the eye sees |
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Total Magnification |
Equal to the power of the ocular lens multiplied by the power of the objective lens used |
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Resolution |
Ability to discriminate two close objects as separate. |
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Resolving Power |
- Determined by the amount and physical properties of the visible light that enters the microscope - More light delivered to the objective lens, the greater the resolution - Size of the objective lens opening decreases with increasing magnification, allowing less light to enter the objective - thus it may be necessary to increase the light at higher magnifications |
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Components of the Miscroscope |
Base Substage light Light control Knob Stage Mechanical Stage Condenser Iris diaphragm lever Adjustment Knobs (Coarse and Fine) Head Arm Nosepiece Objective Lenses Ocular Lens(es) |
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Base |
Bottom of microscope. Provides sturdy flat surface to support and steady the microscope |
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Substage light |
Located in the base. The light from the lamp passes directly upward through the microscope |
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Light control knob |
Located on the base or arm. Allows you to adjust the light intensity |
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Stage |
Platform that the slide rests on while being viewed |
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Mechanical stage |
Holds the stage in position for viewing and has two adjustable knobs that control the precise movement of the slide |
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Condense |
Small nonmagnifying lens located beneath the stage that concentrates the light on the specimen |
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Iris diaphragm lever |
Shutter within the condenser that can be controlled by a lever to adjust the amount of light passing through the condenser. |
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Coarse adjustment knob |
Allows you to make large adjustments to the height of the stage to initially focus your specimen |
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Fine adjustment knob |
Used for precise focusing once the initial coarse focusing has been complete |
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Head |
Attaches to the nosepiece to support the objective lens system. |
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Arm |
Vertical portion of the microscope that connects the base and the head |
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Nosepiece |
Rotating mechanism connecting to the head that carries 3-4 objective lenses. |
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Objective lenses |
Attached to the nosepiece. Usually a compound light microscope has four objectives - Scanning (4x) - Low Power (10x) - High Power (40x) - Oil immersion (100x) |
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Ocular lens(es) |
Located in the eyepieces at the superior end of the head. |
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Microscope Field |
- Decreases with increasing magnification |
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Diameter of field A * Total magnification of field A = Diameter of field B * Total magnification of field B |
How to calculate field diameter? |
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Meter (m) Centimeter (cm) Millimeter (mm) Micrometer (um) Nanometer (nm) |
Metric Units of Length |
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10-2 m |
1 cm = |
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10-3 m |
1 mm = |
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10-6 m |
1 um = |
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10-9 m |
1 nm = |
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Depth of Field |
- Thickness of the plane that is clearly in focus - Greater at lower magnifications - Decreases as magnification increases |
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Wet Mount |
- A method to prepare cells for viewing under a microscope where the specimen is mixed with physiological saline and stained |