Microscope Flashcards
head
- upper part of frame
- supports lenses
- also called body tube
arm
- vertical part of frame
- connects head and base
light switch
- turns lights on and off
rheostat
- adjusts light intensity
- also called light intensity knob
base
- bottom part of frame
- contains light source
light source
- found within the base
- illuminates the specimen
ocular lenses
- the eyepieces provide upright virtual image
- 10X magnification
revolving nosepiece
- supports objective lenses
- rotates to change objective lens
slide clips
- holds slide in place on stage
mechanical stage
- platform for slide to sit on
mechanical stage adjustor knob
- moves stage forward, back, left, or right
fine focus knob
- used for precision focusing
coarse focus knob
- raises or lowers the stage
objective lenses
- create real upside down image
- four strengths
scanning lens
4x magnification
low power lens
10x magnification
high power lens
40x magnification
oil immersion lens
100x magnification
condenser
- lens below the stage
- concentrates light onto the specimen
iris diaphragm
- adjusts contrast
- opens and closes to regulate the amount of light reaching the condenser
cytology
study of cells
histology
study of tissues
gross anatomy
structures large enough to see with the naked eye
Before using the microscope
- clean all lenses by carefully wiping them with lens paper.
- plug in the microscope
- make sure the rheostat is on its minimum position before turning on the light source
finished working with the microscope
- remove the slide & wipe the oil off the immersion oil objective and the slide
- rotate the nosepiece to put the scanning lens in place and turn the coarse adjustment knob so that the stage is in its lowest position
- turn the rheostat to low before turning off the light source
- turn off the light source and remove the slide
- use the mechanical stage adjuster knob to make sure the stage arm is not sticking out beyond the stage
- unplug the power cord and carefully wrap it around the microscope and tuck in the plug so that there are no dangling cords;
- cover microscope (if cover available); andcarefully carry it to its proper storage cabinet.
resolution
The capability of human eye or a device to distinguish finer details of an object
resolution of human eye
0.14 mm/140 micrometer
resolution of light microscope
0.0002 mm/0.2 micrometer
field of view
area of the slide that is visible to you when looking through the microscope
working distance
It is the distance between the front lens of the objective and the surface of the cover glass on the slide when the object is in sharp focus.
high power
- lens closest to slide
- 400x total magnification
- smallest field of view
- largest image
low power
- lens medium distance from slide
- 100x total magnification
- intermediate size field of view
- intermediate size image
scanning power
- lens farthest from the slide
- 40x total magnification
- largest field of view
- smallest image
Parfocal objectives
need little or no fine adjustment when moving from one to the other objective.
cytoplasm
- semi-solid substance of cell
- location of organelles
nucleus
- contains cell’s DNA
plasma membrane
- outermost boundary of the cell
