This site contains a collection of images of human embryos covering Carnegie Stages 13 (day 28) through 23 (day 56) obtained using magnetic resonance imaging. It is intended to serve anyone who is interested in understanding human embryonic development. Once a viewer has selected a stage of development, then the subsequent page provides a brief description of the characteristic features of that stage, a link to a Quicktime movie showing the exterior of the embryo as it rotates, and images are presented with the option of selecting a variety of sections in the axial (transverse), sagittal or coronal (frontal) plane. Selecting a particular plane by clicking on it results in sections of the embryo popping up in a new window. For each slice three different MRI imaging techniques are used and all three images are shown side by side. The site is a collaboration funded by the National Institute of Child Health and Human Development
Target Student Population:
Undergraduate biology majors, medical students
Prerequisite Knowledge or Skills:
Type of Material:
HTML, Quicktime plugin
Evaluation and Observation
Quality of Content: (4.0) (4.0) = (4.0)
The site offers very complete coverage of the range of stages indicated (although stage 21 is missing).
The material is accurately described on the index page for each stage.
Provides material on human development that is not readily available elsewhere.
Excellent material including hundreds of images presented in a clear and well organized fashion.
The images are all at a fairly low resolution (typically 256 x 256 pixels) and it would greatly improve the site if higher resolution images were made available for those wishing to see more detail.
Potential Effectiveness as a Teaching Tool
Potential Effectiveness as a Teaching Tool: (4) (4) = (4)
The multiple images allow one to understand the relationships between various parts of the embryo and allow flexibility of use.
Although the site does not include any assignments one could certainly devise assignments using this material.
Although the learning objectives are implicit they are not clearly stated.
Some labeling of selected images and additional text descriptions would help in orienting the viewer to the main structures that are visible in each section and would make the site more effective as an educational tool.
Ease of Use for Both Students and Faculty
Usability: (5) (5) = (5)
The site is easy to use
Has clear instructions for navigating through the images.
The text is well written.
The site is generally free of broken links or other such problems.
Generally the images download quickly with the exception of the .mov files which are large.
The .mov files that allow visualization of the entire embryo as it rotates would be unusable for someone using a dialup modem since the files are in the megabyte size range.