Pancreas

HISTOLOGY VIRTUAL SLIDE BOX

Virtual slides available on the Web from universities and other sources

A. K. Christensen, University of Michigan Medical School
(www.umich.edu/~akc/slidebox.htm)

Histology (also called microscopic anatomy) is the understanding of biological organization at the organelle, cell, tissue and organ levels, studied primarily by light and electron microscopy. Histological studies with the light microscope usually involve the viewing of histological sections (about 5 µm thick) that are mounted on 1x3" glass slides and are stained with various dyes to make the structures visible. In the laboratory portion of histology courses, the students have access to a light microscope, and view histological slides from a slide box usually containing about 100 to 200 slides.

Advances in digital imaging over the last decade or so have made it possible to scan microscope images of sections from glass slides. This now allows students to view the sections with a computer, rather than with a light microscope, making the laboratory study of histology more accessible and convenient. The goal of these "virtual slides" (as they are now called) is to have enough information in the scanned section so the section as a whole can be viewed, and then small areas anywhere on the section can be blown up to higher magnification, comparable to what would be seen with a microscope objective lens of 20X, 40X, or even higher. In order to accomplish this, it is necessary first to make a large number of small area scans at high magnification, and then reconstruct the low power image as a mosaic of the high magnification images. The resulting overall computer file for a section is very large (usually several GB), so you would not have these files on your computer, but rather would access them from servers on the Internet or on a local area network.

Some universities and other institutions now have substantial collections of histological virtual slides that are openly available on the Web. The ones used in the slide list below are:

In the list below, histology virtual slides from the various sources are organized under the usual subject headings of a conventional histology course. The source of each slide is indicated by a code name (for example, umich) derived from the Web address. The slides are usually numbered. Click the number to see the slide. To return to the list, click the back arrow or (on Internet Explorer) right click the back arrow and then choose "Histology virtual slide box." Slides that have no number are marked with a zero (0), which can also be clicked. If there are two slides with the same number but different magnifications, then the number will indicate this (for example, 126_40X). Names of some items that might be seen in a slide are enclosed in parentheses. The coordinate location of a particularly good example of a hard-to-find item may be listed in square brackets (for example, [17152 x 18116]; coordinates are available on the Aperio ImageScope viewer used for the University of Michigan virtual slide collection; to enter coordinates, click "Go To"). At higher magnification, some areas of a section may not be in sharp focus (the image looks fuzzy), because the section on the glass slide that was scanned was not completely flat -- look around for areas that are in better focus. The sections are usually stained with hematoxylin and eosin (H&E), unless otherwise specified. When you are studying a particular tissue or organ, you may find it useful to make a printout of that portion of this list (select relevant material, then print the selection)


EPITHELIAL TISSUE


CONNECTIVE TISSUE


MUSCLE


NERVOUS SYSTEM


CARTILAGE, BONE AND BONE DEVELOPMENT


CARDIOVASCULAR SYSTEM


BLOOD AND BONE MARROW


LYMPHATIC SYSTEM


SKIN AND MAMMARY GLAND


RESPIRATORY SYSTEM


URINARY SYSTEM


DIGESTIVE SYSTEM: ORAL CAVITY, SALIVARY GLANDS


DIGESTIVE SYSTEM: PHARYNX, ESOPHAGUS, STOMACH, SMALL INTESTINE, COLON


DIGESTIVE SYSTEM: LIVER, GALLBLADDER


DIGESTIVE SYSTEM: PANCREAS


ENDOCRINE SYSTEM


MALE REPRODUCTIVE SYSTEM


FEMALE REPRODUCTIVE SYSTEM


EYE


EAR