UNSW Embryology

DEVELOPMENT OF THE SKIN, HAIR AND NAILS
Embryology Home Page

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Page LinksIntroductionReading Computer Activities ObjectivesLearning activities Integumentary System OverviewTermsReferencesAbout Notes

Page 2 | Abnormalities | OMIM | Questions | Medline
Page 3 | Pig Stage 13/14
Page 4 | Human (Stage22) | Selected Human highpower
Text only page | WWW Links

Introduction

Reading

  • Human Embryology (2nd ed.) Larson
  • The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Ch20: P513-529
  • Before We Are Born (5th ed.) Moore and Persaud Ch21: P481-496
  • Essentials of Human Embryology Larson Ch14: P303-315
  • Human Embryology, Fitzgerald and Fitzgerald
  • Color Atlas of Clinical Embryology Moore Persaud and Shiota Ch15: p231-236

Computer Activities

UNSW Embryology:

Embryo Images Unit:

Objectives

Learning activities

Integumentary System Overview

  • Ectoderm and Mesoderm Origin

4 weeks

  • simple ectoderm epithelium over mesenchyme.

1-3 months

  • ectoderm- germinative (basal) cell repeated division of generates stratified epithelium.
  • mesoderm- differentiates into connective tissue and blood vessels.

4 months

  • basal cell- proliferation generates folds in basement membrane.
  • neural crest cells- (melanocytes) migrate into epithelium. These are the pigment cell of the skin.
  • embryonic connective tissue- differentiates into dermis, a loose ct layer over a dense ct layer. Beneath the dense ct layer is another loose ct layer that will form the subcutaneous layer.
  • Ectoderm contributes to nails, hair follictles and glands.
  • Nails form as thickening of ectoderm epidermis at the tips of fingers and toes. These form germinative cells of nail field.
  • Cords of these cells extend into mesoderm forming epithelial columns. These form hair follocles, sebaceous and sweat glands.

5 months

  • Hair growth initiated at base of cord, lateral outgrowths form associated sebaceous glands.
  • Other cords elongate and coil to form sweat glands.
  • Cords in mammary region branch as they elongate to form mammary glands. These glands will complete development in females at puberty. Functional maturity only occurs in late pregnancy.

References

About Notes

  • Lecture notes from the Anat 3311 1997 Science Embryology course compiled and written by Dr Mark Hill. Some notes derived from historic class notes.
  • Note Links to OMIM Entries are copies of originals for computers without internet access. Computers with internet access can directly access the database.

Links
Serial Sections Homepage
Human Homepage
Pig Homepage

m.hill@unsw.edu.au
Date Last Modified: 31/3/99
This site maintained by Dr M. Hill