INTEGUMENTARY SYSTEM OVERVIEW
INTRODUCTION p. 88
INTEGUMENTARY STRUCTURE AND FUNCTION p. 88
1. Describe and compare the structure and functions of the skin with the underlying connective
tissue.
THE EPIDERMIS p. 89
Layers of the Epidermis p. 89
Thick and Thin Skin p. 91
2. Describe the four primary cell types found in the epidermis.
3. Explain the factors that contribute to individual and racial differences in skin, such as skin color.
4. Discuss the effects of ultraviolet radiation on the skin and the role played by melanocytes in
this regard.
THE DERMIS p. 93
Dermal Organization p. 93
Other Dermal Components p. 95
5. Describe the organization of the dermis.
6. Discuss dermal components, including blood supply and nerve supply.
THE SUBCUTANEOUS LAYER p. 95
7. Describe the structure of the subcutaneous layer(hypodermis) and its importance.
ACCESSORY STRUCTURES p. 96
Hair Follicles and Hair p. 96
Glands in the Skin p. 99
Nails p. 104
8. Discuss the anatomy and functions of the skin’s accessory structures: hair, glands, and nails.
9. Describe the mechanisms that produce hair, and determine hair texture and color.
10. Compare and contrast sebaceous and sweat glands.
11. Describe how the sweat glands of the integumentary system function in the regulation of body
temperature.
LOCAL CONTROL OF INTEGUMENTARY FUNCTION p. 104
12. Explain how the skin responds to injuries and repairs itself.
AGING AND THE INTEGUMENTARY SYSTEM p. 105
13. Summarize the effects of the aging process on the skin.
NEUROLOGY 2004;62:774-777
© 2004 American Academy of Neurology
The effect of age and gender on epidermal nerve fiber density
L. G. Gøransson, MD, S. I. Mellgren, MD, PhD, S. Lindal, MD, PhD and R. Omdal, MD, PhD
From the Department of Internal Medicine (Drs. Gøransson and Omdal), Rogaland Central Hospital,
Stavanger; Institute of Clinical Medicine (Drs. Mellgren and Omdal), University of Tromsø; and
Departments of Neurology (Dr. Mellgren) and Pathology (Dr. Lindal), University Hospital of North Norway,
Tromsø, Norway.
Address correspondence and reprint requests to Dr. Lasse G. Gøransson, Rogaland Central Hospital,
Department of Internal Medicine, P.O. Box 8100, 4068 Stavanger, Norway; e-mail: gola@sir.no
Objective: Sensory neuropathies often involve small-diameter myelinated and
unmyelinated nerve fibers, and neurologic and electrophysiologic findings may be
normal unless larger nerve fibers are involved. The small (intra)epidermal nerve fibers
(ENFs) now can be visualized with immunohistochemical techniques using the
panaxonal marker anti-protein gene product 9.5 (PGP 9.5). Using this technique, the
authors have established a reference range for ENF in a healthy white population and
evaluated the reliability of the method.
Methods: Two punch biopsies, 3 mm in diameter, were taken from the distal part of the
leg in 106 healthy volunteers (mean age, 49.0 ± 19.6 years). Fifty-micrometer frozen
thick sections were incubated with rabbit polyclonal antibodies to human PGP 9.5. The
number of ENF/mm then was reported as the mean of counts in six sections (three
sections from each of the two biopsies).
Results: The mean number of ENFs was 12.4 ± 4.6 mm. In a multiple regression
model, the density of ENF depended on age and gender (Y = 13.92 + 2.25 (gender) 0.06 x age). The mean difference in ENF by intraobserver analysis was 0.2 ± 1.2
ENF/mm, and by interobserver analysis, it was 0.4 ± 1.5 fibers/mm.
Conclusion: Normal means and ranges for the density of epidermal nerve fibers in a
reference population have been established. The density of epidermal nerve fibers
decreases with age and is lower in men compared with women. Intraobserver and
interobserver analysis proves the reliability of the method.
Received December 6, 2002. Accepted in final form November 18, 2003.