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The Embryonic Disk Overview Structure & content Study tools Technical notes For teaching staff New in this version Users & comments


Text and images
© Jeremy Cook 1997–2008


Contents page

Egg to Embryo page

Image from The Germ Line


Structure and content : 1
Subject coverage and 
core material

The resource focuses initially on the crucial first 28 days of development, when the embryo takes shape and its major organ systems become laid out, and on key events in the following weeks that affect more than one body system.

This focus is designed to support foundation studies in integrated medical curricula.

Introduction to 'The Embryonic Disk': a primer on the uses of embryology, its terminology, and navigating around the resource.
Egg to embryo: a beginner's guide to the formation of the human embryo from fertilization to folding, in 30 images and about 1,000 words.
Timetable for weeks 1-4: the first month of life laid out on a single page, with each day hotlinked to an illustrated core description and narrative of its main events.
Schematic for weeks 5-38: later stages of development organized by body system, with key multi-system events shown spanning the relevant individual systems.

Other core sections describe the normal and anomalous development of all the major thoracic and abdominal organ systems, the nervous system, and the head and neck.

Development by region and system: the development of individual regions and organ systems, including the head and neck, nervous system and special senses, cardiovascular system, digestive system, excretory system and reproductive system.

Events with a still wider time-span, such as the germ line, gametogenesis and fertility, the placenta, and the development of the structures of speech and hearing, are covered in a series of topic overviews.

The germ line: an illustrated account of the cell line that carries our genes from fertilization, throughout development, to the next generation; includes the ovarian cycle and spermatogenesis.
The placenta and membranes: their development, structure, function and common abnormalities.
Twins and more: the varied embryological bases of non-identical, identical and conjoined twins, illustrated with diagrams and photographs.
Parts of speech: the embryology of speech and hearing, aimed explicitly at students of speech and language but relevant to all student groups.

There is also a special section on preimplantation genetic diagnosis, illustrating powerful new techniques for combining genetic diagnosis with in vitro fertilization.