1. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley CHAPTER Medical Language Second Edition Dermatology Dermat/o- = skin -logy = study of 7

2. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Skin Also known as the Integumentary system Skin is the largest organ in the body When stretched out, the skin covers 2 square meters Every 28 days your skin renews itself –Every minute your skin sheds around 30,000 dead cells

3. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Anatomy of the Integumentary System Skin consists of two different layers: – epidermis – dermis

4. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Epidermis –Thin, outermost layer of the skin. –It contains cells that have no nuclei and are filled with keratin, a hard, fibrous protein. –Form a protective layer  they are dead cells, so they are constantly being shed

5. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Epidermis Epidermis (cont’d) –The deepest part (basal layer) is composed of living cells that are constantly dividing and being forced to the surface –Does not contain any blood vessels –Contains melanocytes pigment cells that produce melanin

6. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Dermis –A thicker layer of skin beneath the epidermis –Contains collagen fibers and elastin fibers –Contains:  arteries, veins, and neurons  hair follicles, sebaceous glands, and sweat glands

7. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Figure 7-2 Epidermis and dermis

8. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Anatomy of the Integumentary System (cont’d) Subcutaneous Tissue –A loose, connective tissue directly beneath the dermis of the skin –Composed of adipose tissue –Provides a layer of insulation to conserve internal body heat –Acts as a cushion to protect the bones and internal organs

9. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Anatomy of the Integumentary System (cont’d) Sebaceous and Sweat Glands –Sebaceous glands  secrete sebum through a duct into a hair follicle.  AKA oil glands. –Sudoriferous glands  AKA Sweat glands  Sweat contains water, sodium, and small amounts of body waste  Help regulate body temp

10. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Anatomy of the Integumentary System (cont’d) Hair –Covers most of the body –Forms in a hair follicle in the dermis –Melanocytes give color to the hair –Filled with keratin

11. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Anatomy of the Integumentary System (cont’d) Nails –Cover and protect the distal ends of the fingers and toes –Each nail consists of a nail plate, nail bed, cuticle, lunula, and nail root.

12. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Physiology of an Allergic Reaction An allergy or allergic reaction is a hypersensitivity response to certain types of antigens known as allergens. Allergens include cells from plant and animal sources (foods, pollens, molds, animal dander), as well as dust, chemicals, and drugs.

13. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Physiology of an Allergic Reaction (cont’d) The basis of all allergic reactions is the release of histamine from basophils in the blood and mast cells in the connective tissue. A local reaction occurs when an allergen touches the skin or mucous membranes of a hypersensitive individual

14. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Physiology of an Allergic Reaction (cont’d) Histamine causes redness (inflammation), swelling (edema), irritation, and itching.

15. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Physiology of an Allergic Reaction (cont’d) A systemic reaction occurs when allergens are inhaled or ingested by, or injected into, a hypersensitive person, causing symptoms in several body systems. Histamine constricts the bronchioles, dilates the blood vessels throughout the body, and causes hives on the skin.

16. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Physiology of an Allergic Reaction (cont’d) Anaphylaxis is a severe systemic allergic reaction that can be life threatening; it is also known as anaphylactic shock.

17. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley

18. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley Abbreviations