Developmental Biology - 3-4 mm Frog Image

INTRODUCTION

The 24 Hour Chick Embryo

Serial Sections

The study of serial sections allows for the study of the microscopic anatomy of the embryo, in particular, the internal anatomy of the embryo. Many features that are not evident in the study of the whole embryo can be examined by viewing a sequence of sections of the embryo. Serial sections consist of the entire embryo sectioned in a certain plane. In the case of serial cross sections, the entire embryo was sectioned perpendicularly to the cranio-caudal axis from the beginning of a portion of the head to the end of the tail and all the sections were laid out in sequence on microscope slides. The embryo from which the accompanying photomicrographs were taken consisted of 240 sections


Navigation within the Web Site

The screen consists of three frames, a photographic frame on the upper left, a text frame on the lower left, and an orientation frame on the right.

The photographic frames contain photomicrographic images of cross sections of a 24 hour chick embryo taken from a set of 240 serial cross sections. The photographs are numbered one to 15 out of a possible 15. A button below the photograph allows you to click and move to the following photograph.

The largest frame on the screen is the text frame. This frame has a scroll bar on the right hand side of the frame that allows you to move text upward and downward. The text consists of descriptive paragraphs that begin with a title that gives the section number out of the total number of 240 sections that comprise the embryo. A listing of the major visible features occurring at this particular level of sectioning follows the section number. Clicking on the title will bring the corresponding photograph into the photographic screen.

The orientation frame is located on the right hand side of the screen. This frame contains a thumbnail size diagram of a dorsal view of a whole 24 hour chick embryo. A vertical line indicates the level of sectioning of each cross sectional photograph. A button list, allows you to click and move to a previous section, the next section, the main menu, or the index.

Note that the images are designed to display optimally with a screen resolution of 600 X 800 pixels. You may wish to adjust your video display.