Lab Quiz 2: Parts of a Microscope Flashcards
Transmission Microscope
The general term used for any type of microscope where the light is transmitted from a source on the opposite side of the specimen from the objective lens.
Compound Microscope
When a scope has a minimum of two magnifying lenses (objective lens and ocular lens in our scopes).
Binocular
Two eyepieces.
Monocular
One eyepiece.
Stereoscopic (Dissecting) Microscope
A microscope typically using light reflected from the surface of an object rather than transmitted through it. The scope involves relatively low magnification good for viewing large, thick objects (produces 3D image).
Transmitted Light
Light passing through an object, used by many types of microscopes.
Reflected or Incident Light
Light directed down on an object and reflected into objective lens’ used by dissecting scopes.
Magnification
The ratio of the image size to the actual size; apparent enlargement of an object.
Resolution
The ability of a microscope to distinguish between two very close points.
Electron Microscope
Microscope that uses electrons as a source of illumination.
Ocular Lens
Lens that we use as an eyepiece with a magnification of 10x.
Objective Lenses
Lenses near the stage on the revolving nosepiece usually with a magnification of either 4x, 10x, and 40x.
Condenser
This piece collects and focuses the light from the illuminator on to the specimen.
Iris Diaphragm
This piece controls the amount of light reaching the specimen.
Important to remember this about compound microscopes:
The image you see through a compound microscope is inverted.
Which microscope has a relatively low magnification?
Stereoscopic or Dissecting Microscope (often 2x - 30x)
List advantages of stereoscopic or dissecting microscopes:
Good for viewing large objects, good for dissecting many materials, large depth of field, illuminate sample using incident (reflected) light as well as transmitted light
List advantages of electron microscopes:
Greater magnification and resolution
Transmission Electron Microscope (TEM)
Microscope that transmits a beam of electrons through a thin slice of sample producing a 2D image.
Scanning Electron Microscope (SEM)
Microscope that projects an electron beam on whole samples to get a 3D image. Electrons bounce off (don’t pass through) making it possible to visualize the surface structure of the specimen.
Rheostat
This piece controls the intensity of the light emitted by the microscope’s light source.
