the microscope mr. gacc/bakka bhs visit for more free powerpoints
TRANSCRIPT
The Microscope
Mr. Gacc/Bakka
BHSVisit www.worldofteaching.com for more free powerpoints
The History• Many people experimented with making
microscopes
• Was the microscope originally made by accident? (Most people were creating telescopes)
• The first microscope was 6 feet long!!!
• The Greeks & Romans used “lenses” to magnify objects over 1000 years ago.
The History Hans and Zacharias Janssen of Holland in the 1590’s created the “first” compound microscope
Zacharias Jansen1588-1631
The “First” Microscope
The History
• Robert Hooke & • Anton van Leeuwenhoek
made improvements by working on the lenses
Anton van Leeuwenhoek1632-1723
Robert Hooke 1635-1703
Hooke Microscope
History•In 1665 Robert Hooke examined a thin slice of cork with a single magnifying lens and observed tiny compartments
•He gave them the latin name cellulae, meaning small rooms - hence the origin of the term cell.
•He later observed cells in plant tissues and observed the cells were “fill’d with juices”
History• In the early 1700’s Leeuwenhoek
looked at pond water and called the microscopic organisms “animalcules”
• These were the first observations of living cells
• 1820 - Robert Brown observed a nucleus in orchid cells
HistoryIn 1838, Matthius Schleiden stated all plants are made of cells
Theodor Schwann stated all animals are made of cells .
Cell Theory - 3 parts
1. Cells are the basic unit of life
In 1855, Rudolf Virchow further extended the cell theory and added:
2. All organisms are composed of one or more cells
3. All cells come from pre-existing cells
How a Microscope Works
Convex Lenses arecurved glass used to make microscopes(and glasses etc.)
Convex Lenses bendlight and focus it inone spot.
How a Microscope WorksOcular Lens(Magnifies Image)
Objective Lens(Gathers light, magnifies and focuses image inside body tube)Body Tube
(Image Focuses)
•Bending Light: The objective (bottom) convex lens magnifies and focuses (bends) the image inside the body tube and the ocular convex (top) lens of a microscope magnifies it (again).
The Parts of a Microscope
Body Tube
• 1. The body tube holds the objective
lenses and the ocular lens at the proper distance
Diagram
Nose Piece
• 2. The Revolving Nose Piece holds the objective lenses and can be turned
to increase the magnification
Diagram
Ocular Lens or Eye lens
• 3. Magnifies the specimen image 10x
Diagram
Objective Lenses
• 4. The Objective Lenses increase magnification from 4x to 10x
to 40x.
Diagram
Stage Clips
• 5. These 2 clips hold the slide/specimen in place on
the stage.
Diagram
Diaphragm
• 6. The Diaphragm controls the amount of light on the slide/specimen
Turn to let more light in or tomake dimmer.
Diagram
Light Source
• 7. Projects light upwards through the diaphragm, the specimen and
the lenses
• Some have lights, others have mirrors where you must move the mirror to reflect light
Diagram
Arm
• 8. Used to support the microscope when carried. Holds the body
tube, revolving nose piece and objective lenses.
Diagram
Stage
• 9. Supports the slide/specimen
Diagram
Coarse Adjustment Knob
• 10. Moves the stage up and down (quickly) for focusing your
image.
• Never use coarse adjustment under high power!!!!!
Diagram
Fine Adjustment Knob
• 11. This knob moves the stage SLIGHTLY to sharpen the
image.
Diagram
Base
• 12. Supports the microscope
Diagram
Magnification
Magnification
• To determine your magnification…you just multiply the ocular or eye lens by the objective lens
• Ocular 10x Objective 40x:10 x 40 = 400
Objective Lens have their magnificationwritten on them.
Ocular lenses usually magnifies by 10x
So the object is 400 times “larger”
Hand lens - 5x
• Stereo microscope -
10 - 60x & 3d image
Electron Microscopecan focus up 500,000x
Tunneling - cell parts/organells
2 types of electron microscopes
Scanning - 3D image of RBCs & insects
Body Tube
Nose Piece
ObjectiveLenses
Stage Clips
Diaphragm
Light Source
Ocular Lensor eye lens
Arm
Stage
Coarse Adjustment.
Fine Adjustment
Base
Skip to Magnification Section
Using a Microscope• Start on the lowest magnification• Don’t use the coarse adjustment knob
on high magnification…you’ll break the slide!!!
• Place slide on stage and lock clips• Adjust light source (if it’s a mirror…don’t
stand in front of it!)• Use fine adjustment to focus• Use diaghram for light intensity
Caring for a Microscope
• Clean only with a soft cloth/tissue
• Make sure it’s on a flat surface
• Don’t bang it
• Carry it with 2 HANDS…one on the arm and the other on the base
Carry a Microscope Correctly
References
• http://www.cerebromente.org.br/n17/history/neurons1_i.htm• Google Images• http://science.howstuffworks.com/light-microscope1.htm