UNSW Embryology
Embryology Home Page

Development of the Skin, Hair and Nails - text only page
School of Anatomy

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Cell Biology Lab

Introduction

The integumentary system covers the surface of the embryo (skin) and its specialized skin structures including hair, nails, sweat glands, mammary glands and teeth. Ectoderm forms the surface epidermis. Mesoderm forms the underlying connective tissue of dermis. Neural crest cells also migrate into the forming dermis. There is a detailed developmental overview of all these specific structures.

This section of notes still under development.

Page Links | Reading | Computer Activities | Objectives | Learning activities | Serial Sections | Self Assessment Questions | Abnormalities | OMIM Database | About Notes | Next Page

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

  • Understand the differentiation of the epidermis and dermis.
  • Understand the formation of hair hair and nails.
  • Understand the formation of sweat glands, mammary glands
  • Understand the formation of teeth.

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.

 

More detailed Overview? of other Integumentary Structures

OMIM Database Online Mendelian Inheritence in Man Database. OMIM

Internet Search OMIM database with the keyword skin or the above abnormality names.

Note: This database is an external link, not accessible from some computers in the School of Anatomy.
A is available for these computers.

Self Assessment Questions (C.V.S.)

References

PubMed Database

Online Medline Database PubMed- Medline

National Library of Medicine (US) search service to access the 9 million citations in MEDLINE and Pre-MEDLINE (with links to participating on-line journals), and other related databases.

Internet Search this database or use the form below with the keyword skin or related topics. You can also restrict to reviews or by date published.

  • Note: This database is an external link, not accessible from some computers in the School of Anatomy.
  • A Selected List of References from March 1999 search results for "" and "" is available for these computers.

Search Field: Mode:

PubMed

PubMed Search Results Number as of March 1999.

| Pig Embryo | Human Embryo

Pig Embryo

 

Human Embryo

This Page under development March 99

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: 11/3/99
This site maintained by Dr M. Hill