MICROSCOPY STUDY

Microscopy is important to the study of anatomy & physiology!

In your study of Anatomy & Physiology, you will be involved with macroscopic anatomy (i.e. using the naked eye) and microscopic anatomy (using an instrument, the microscope, which provides greater resolution or the capacity to distinguish detail).

Much of the current knowledge of cell structure and therefore, of tissues, organs, etc., has been gained by using three different types of microscopes: the compound light microscope, like the ones available to you in this lab; and two types of electron microscopes, the transmission electron microscope (TEM) and scanning electron microscope (SEM).

Many cell structures are too small to see with a light microscope.

Specimens smaller that 0.3 microns (u) require an electron microscope, which has much greater resolving power than the compound scope. It uses beams of electrons to bombard the specimen instead of light rays, and magnets instead of lenses for focusing.

There are some basic differences between the TEM and SEM. These include the following:

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TEM SEM

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beam of electrons passes beam of electrons is directed

through ultrathin sections over the specimen and then

of specimen reflected from the surface to

a screen or photographic plate

provides details of the gives a three-dimensional image

interior of specimen and is useful in studying

(at different layers if surface features of specimen

multiple sections have

been made of specimen)

(two-dimensional)

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STUDYING AND INTERPRETING MICROGRAPHS

Many of the cell/organelle photos in your textbook and lab manual are either TEM's, SEM's, or diagrams based on them. You should acquaint yourself with both types of electron micrographs. You can begin to accomplish this objective by observing the following photos and diagrams; some of which will also be light micrographs (LM's).

Figure/Page # (Textbook)	Structure	SEM, TEM, or LM?	Magnification (if given)
Fig 3.5a, page 79
Fig 3.5b, page 79
Fig 3.5c, page 79
Fig 3.13a, page 86
Fig 5.14, page 155
Fig 6.7, page 178
Fig 7.5, page 196
Fig 10.1, page 355
Fig 12.1b and c, page 441
Fig 15.28b and c, page 577
Fig 16.3, page 618
Fig 20.7a and b, page 781
Fig 22.28b, page 854
Fig 22.11 page 839