Lab 1 Flashcards
Histology is the study of?
microscopic anatomy of cells, tissues and organs
Compound microscopes use which type of light to view specimens?
white light
-referred to as a light microscope
The first lens ___________ produces and image that magnifies the specimen which is further magnified by ________ that you look directly through
the objective lens
the second lens (oculars)
True or False:
Compound microscopes have a large working distance (distance between the stage and the objectives
False: small working distance making they suited for visualizing prepared specimens on slides
Another example of a light microscope is?
the stereomicroscope or dissection microscope
The two main differences between the compound and stereomicroscope is?
nature of illumination of the specimen
preparation of the specimen
A compound light microscope is a __ -___ magnifier, where the image is magnified by _________ as well as the ______
the objective as well as the ocular
The ocular (eyepiece)
The uppermost lens through which the specimen is viewed
-function to further magnify the image formed by the objective lenses and to project his image to observers eyes
When changing obectives always turn the ______ NEVER push or pull the ______ themselves
nosepiece
objectives
Objectives
the lower lenses that are attached to the nosepiece that magnify and project the image from the slide onto the lenses of the ocular
Objective range:
scanning
low-power
high-power
2.5x, 4x
10x
40x
Stage
where slides are placed- stage clips used to secure the slides
lightsource
incandescent tungsten filament light bulb produces like to illuminate the specimen
condenser
lens system beneath stage used to focus light
-concentrates light rays
iris diapgragm
regulates light entering the microscope
-part of the condenser and controls amoun and angle of light rays
course adjustment knob
used to adjust microscope at low power
fine adjustement knob
used to adjust the microscope into fine focus when using higher power objectives
Total magnification=
ocular power x objective power
The resolution of a microscope is really a measure of?
the fineness of detail that can be visualized in a specimen
Resolution (R)=?
=λ / 2NA
λ= wavelength of illumination
NA= numerical aperture of the objective lens
-NA is the measure of the size or angle of the cone of light that is delivered by the condenser to the object
The higher the NA the ________ the resolution will be. Why?
better the resolution
because R will be smaller
the shorter the wavelength of light the ______ R will be
smaller R will be and the better the resolution
Acheiving a high resolution means getting the ___ as high as possible and the ____ as low
NA
wavelength of light
True of false
Magnification affects reolution
false
magnification has nothing to do with resolution
you do not get a higher resolution at higher power, unless the NA for that lens is higher
If you close the iris diaphragm to reduce the amount of light that reaches the specimen you will also reduce?
the contrast and resolution of the magnified image
Is oil immersion needed for histological specimens of tissue? What about 100x magnification?
no and no
List the steps in preparing a tissue or organ for microscopic examination
- fixation- preserves specimen and prevents deterioration
2. Stain the specimen - sections are stained by one or more dyes to provide contrast
Hematoyxlin is a _____ dye while eosin is a ____ dye
blue/purple
pink
Hematoxylin has high affinity for? Eosin has high affinity for?
acidic cellular material
basic cellular material
