Chapter 4 Integumentary System

Chapter 4 Objective 1: Identify organs and structures of the integumentary system.

Integumentary System The integumentary system is composed of: skin nails hair glands What are the names of the three main layers of skin? Answer: epidermis, dermis and subcutaneous tissue.

Integumentary System Function The skin forms a protective covering that when unbroken prevents entry of bacteria and other invading organisms. The skin also protects the body from water loss and from damaging effects of ultraviolet light. Other functions include regulation of body temperature and synthesis of vitamin D. Hair and nails are accessory structures of the skin.

Structure of the Skin Note the amazing complexity of the many elements that make up the skin structure. What are the names of the three main layers of skin?

Major Structures of the Skin epidermis: outer layer of skin keratin: the scleroprotein component of the horny, or cornified, layer of the epidermis melanin: color, or pigmentation, of skin dermis (also called “true skin”): the inner layer of skin How does melanin help prevent sunburn? Why would dermis be called “true skin”? Is there such a thing as “false skin”?

Major Structures of the Skin (cont’d) sudoriferous glands: tiny, coiled, tubular structures that emerge through pores on the skin’s surface sebaceous glands: secrete sebum (oil) into the hair follicles, where the hair shafts pass through the dermis What might be the purpose of sudoriferous glands? Why would it be important to have sebum (oil) on the hair follicles?

Accessory Structures of the Skin hair: compressed, keratinized cells that arise from hair follicles (sacs that enclose the hair fibers) nails: originate in the epidermis; found on the upper surface of the ends of the fingers and toes Note that hair is a keratinized cell, meaning it has a tough, horny consistency. Where are the hair follicles located? How quickly do nails grow? What would happen if a nail is lost in an accident? Would it grow back?

Chapter 4 Objective 2: Define and spell the word parts related to the integumentary system.

Combining Forms for the Integumentary System cutane/o, derm/o, dermat/o hidr/o kerat/o onych/o, ungu/o seb/o trich/o Review the meaning and use of combining forms. Present the meaning of combining forms for the integumentary system and give examples of how they may be used. Note there are three combining forms for “skin,” and they are used in different ways, depending on the context of the term. Cutane/o used when the subcutaneous layer is involved. Examples include percutaneous and subcutaneous. Derm/o is used when skin is referenced in the middle of a term. Examples include lei/o/derm/a, luek/o/derm/a, pachy/derm/a, xer/o/derm/a, erythr/o/derm/a, epi/derm/al, erythr/o/derm/a, hypo/derm/ic, intra/derm/al, trans/derm/al, and xanth/o/derm/a. Dermat/o is used when skin is referenced first in a term. Examples include dermatitis, dermatoconiosis, dermatofibroma, dermatoautoplasty, dermatoheteroplasty, dermatome, dermatoplasty, dermatologist, and dermatology.

Cross Section of the Skin Use this slide to guide students in completing Exercise Figure A in the text. Answers: 1. horny tissue: kerat/o 2. hair: trich/o 3. skin: cutane/o, dermat/o, derm/o 4. sebum: seb/o 5. sweat: hidr/o How do combining forms change for different layers of the skin?

Combining Forms Commonly Used with Integumentary System Terms aut/o bi/o coni/o crypt/o heter/o myc/o necr/o pachy/o rhytid/o staphyl/o strept/o xer/o What is the combining form for “dust,” and how might it be used in terminology? What is the combining form for “fungus,” and how might it be used in terminology? Ask students to describe the differences between staphyl/o and strept/o.

Prefixes epi- intra- para- per- sub- trans- Review the meaning and use of prefixes. Present the meaning of prefixes for the integumentary system and give examples of how they may be used. Which prefix means “beside,” “beyond,” or “around”? Which prefix means “under” or “below”?

Suffixes -coccus (pl. -cocci) -ectomy -ia -itis -malacia -opsy -phagia -plasty -rrhea -tome Review the meaning and use of suffixes. Present the meaning of suffixes for the integumentary system and give examples of how they may be used. What is the suffix for “excision” or “surgical removal”? What is the suffix for “surgical repair”?

Review Question Which of the following means “eating or swallowing”? pachy/o -phagia -plasty Answer: b) - phagia Ask students to identify the word parts. Ask students to define the other two word parts.

Chapter 4 Objective 3: Define, pronounce, and spell disease and disorder terms related to the integumentary system.

Analyze and Define WR/CV/WR/S onych/o/myc/osis abnormal condition CF of fungus in the nail dermatoconiosis hydradenitis dermatitis Use this slide to guide students in completing Exercise 11 in the textbook.

Chapter 4 Objective 7: Interpret, read, and comprehend medical language in simulated medical statements, documents, and electronic health records.

Read Medical Terms in Use Emily visited the dermatology clinic because of pruritus secondary to dermatitis involving her scalp and areas of her elbows and knees. A diagnosis of psoriasis was made. Eczema, scabies, and tinea were considered in the differential diagnosis. An emollient cream was prescribed. In addition, the patient showed the dermatologist the tender, discolored, thickened nail of her right great toe. Emily learned she had onychomycosis, for which she was given an additional prescription for an oral antifungal drug. Ask students to pronounce and define the bolded terms.