Skin

lbazz

Chapter_16_LO.ppt

Home >Nursing homework help >Skin

Chapter 16
Skin

Learning Objectives

Name the layers of the skin and the accessory structures associated with the skin.
Build medical words using the combining forms that are related to the specialty of dermatology.
Identify lesions, sign and symptoms, and pathologic conditions that relate to the skin.

Learning Objectives (cont’d)

Describe laboratory tests and clinical procedures that pertain to the skin and recognize relevant abbreviations.

Apply your new knowledge to understanding medical terms in their proper contexts, such as medical reports and records.

Chapter 16
Lesson 16.1

INTRODUCTION

Skin: Integumentary system

weighs 8-10 lbs.
covers 22 sq. ft. in average adult

What tissues can you predict will be integrated into this organ system?
What are the unique qualities of epithelium that make it a suitable tissue for covering the body?
How is the epithelium on the “outside” (part of the skin) similar to that on the inside of the body?

Functions of Skin

Provides protective membrane
Skin glands lubricate and cool the skin
Receptor for sensations
Helps Maintain body temperature

Have students define desiccation. Ask them to list three ways that skin guards against desiccation.
How does skin guard against acidic secretions?

Functions of Skin (cont’d)

Produces sweat: sweat glands produce watery secretion that evaporates and cools

Produces sebum: sebaceous glands produce oily secretion that lubricates skin and hair

Receives sensation: pain, temperature, pressure, and touch

Thermoregulates: interprets message from heat center in the brain

Ask the students to define the word thermoregulate. How does the skin thermoregulate?
There are multiple mechanisms for thermal control. Describe at least three or four.

STRUCTURE OF THE SKIN

Epidermis: outermost, thin cellular membrane

Dermis: next layer; dense fibrous, connective tissue

Subcutaneous tissue (hypodermis): thick, fat-containing tissue

What does the epidermis lack? Ask the students to describe what it is dependent upon.
What is the dermis composed of? Ask the students to describe what supports this layer.
Ask the students what lipocytes are and where they are found.

Structure of the Skin (cont’d)

In the inset of this picture (B) you can see what are called dermal papillae. They look like wavy folds. What is the advantage of this kind of tissue architecture?
The dermis appears to be pushing up folds into the epidermis. Why?
Is the epithelium vascular? Why is that an advantage or disadvantage?

Structure of the Skin (cont’d)

In the inset of this picture (B) you can see what are called dermal papillae. They look like wavy folds. What is the advantage of this kind of tissue architecture?
The dermis appears to be pushing up folds into the epidermis. Why?
Is the epithelium vascular? Why is that an advantage or disadvantage?

HAIR: cells filled with the hard protein;

keratin

Hair follicles: shafts that hold the hair
Five million hairs on body; 100,000 on head
Melanocytes at the root form the color
Grow 0.5 inch (1.3 cm) per month
Cutting does not affect growth

ACCESSORY ORGANS
OF THE SKIN

Ask the students to describe melanocytes and where they can be found.
What functions does hair have? (sensory, thermoregulation)

ACCESSORY ORGANS
OF THE SKIN

Accessory Organs of Skin (cont’d)

NAILS: hard keratin plates covering toes and fingers

lunula
cuticle
paronychium

How are hair, nails, and epidermis alike?
How do these structures grow and slough off cells?

Accessory Organs of Skin (cont’d)

GLANDS: Sebaceous and Sweat

Sebaceous glands secrete oily sebum into hair follicle to lubricate
Sweat glands secrete into pores to moisten and cool
Both subject to bacterial growth

Why do people have so many sweat glands?
Could people live without sweat glands?
Do sebaceous glands make hair feel oily?

Accessory Organs of Skin (cont’d)

Sebaceous gland

Sweat glands: eccrine sweat gland, and apocrine sweat gland.

Why do people have so many sweat glands?
Could people live without sweat glands?
Do sebaceous glands make hair feel oily?

COMBINING FORMS
AND TERMINOLOGY

COMBINING FORMS

adip/o fat
albin/o white
caus/o burn, burning
cauter/o heat, burn
cutane/o skin
derm/o skin

Combining Form Meaning

COMBINING FORMS

dermat/o skin
diaphor/o profuse sweating
erythem/o redness
erythemat/o redness
hidr/o sweat
ichthy/o scaly, dry

Combining Form Meaning

COMBINING FORMS
AND TERMINOLOGY

COMBINING FORMS

kerat/o hard, horny tissue
leuk/o white
lip/o fat
melan/o black
myc/o fungus
onych/o nail

Combining Form Meaning

COMBINING FORMS
AND TERMINOLOGY

COMBINING FORMS

phyt/o plant
pil/o hair, hair follicle
py/o pus
rhythid/o wrinkle
seb/o sebum
squam/o scale-like

Combining Form Meaning

COMBINING FORMS
AND TERMINOLOGY

COMBINING FORMS

steat/o fat
trich/o hair
ungu/o nail
xanth/o yellow
xer/o dry

Combining Form Meaning

COMBINING FORMS
AND TERMINOLOGY

COLORS

Why do people have so many sweat glands?
Could people live without sweat glands?
Do sebaceous glands make hair feel oily?

QUICK QUIZ:

Which combining form refers to white?

chlor/o

jaund/o

melan/o

albin/o

CORRECT Answer is D, albin/o means white as in albinism

QUICK QUIZ:

Which combining form refers to the same color as jaund/o?

xanth/o

chlor/o

erythr/o

cyan/o

CORRECT Answer is A, xanth/o means yellow as in xanthoma See page 632 for table referencing colors.

Chapter 16
Lesson 16.2

Cutaneous
Lesions

LABEL the following lesions:

What is the definition of a lesion?
Which of these lesions are similar but are differentiated by size?
Which lesions involve the dermis layer?

REVIEW the following lesions:

Cutaneous
Lesions

What is the definition of a lesion?
Which of these lesions are similar but are differentiated by size?
Which lesions involve the dermis layer?

Signs and Symptoms

Alopecia:

absence of hair where it normally grows

What are some causes of alopecia?
Are there any treatments for baldness? Are they successful?
Another form of alopecia is a result of trichotillomania, or obsessive hair-pulling.

Signs and Symptoms (cont’d.)

Ecchymosis: blue-black marks on the skin

What can cause ecchymosis?
What is the treatment?

Petechia: small pinpoint hemorrhage

Signs and Symptoms (cont’d.)

Use the pictures as examples. Ask students whether they have ever been diagnosed with any of the skin conditions mentioned.
What diseases are associated with these symptoms?
What is pruritus?
What is purpura?

Urticaria: acute allergic reaction with red, round wheals on skin

Signs and Symptoms (cont’d.)

What is the common term for urticaria?
Have students discuss their experiences (or that of someone they know) with hives.
What causes hives? How long do they last?

Abnormal Conditions

Acne: papular and pustular eruption of skin with increased production of sebum

What is the medical term for a blackhead?
Why are adolescents so prone to acne? Myths and reality.
Are over-the-counter treatments effective?

Burns: injury to tissue due to heat, chemical, electric shock, lightning or radiation. Image shows (A), Second degree burn and (B) shows Third degree burn.

Abnormal Conditions (cont’d.)

Go over the different degrees of burns and use a chart with the layers of the skin to demonstrate how deep the burns go.
What percentage of body burn results in death? Why?

Abnormal Conditions (cont’d.)

Cellulitis: diffuse acute infection of skin
Eczema: inflammation of skin with erythematous and papulovesicular lesions caused by allergy
Exanthematous viral diseases: rash due to virus (e.g. rubella)
Gangrene: death of tissue with loss of blood supply

Which of these diseases is/are common in children? Why?
What are other diseases that are similar to eczema? Are they all treated in the same way?

Abnormal Conditions (cont’d.)

Impetigo: contagious pyoderma caused by staph or strep
Psoriasis: chronic recurrent dermatosis with silver gray scales that itch
Scabies: parasitic (tiny mites) and infectious pruritus
Scleroderma: chronic and progressive disease of skin with hardening of connective tissue

Which of these diseases are NOT contagious?
Which disease may worsen if the patient experiences anxiety?

Abnormal Conditions (cont’d.)

Systemic lupus erythematosus (SLE): inflammatory disease of collagen in skin, joints, and internal organs

What are the current thoughts about the origin of SLE? How is it treated?
Where have we discussed it before because of other organ systems it affects?

Abnormal Conditions (cont’d.)

Tinea corporis

Tinea unguium

Tinea—infection of the skin caused by fungus.

What is tinea? (fungal infection of skin or nails i.e. ringworm, athlete’s foot)
What is vitiligo? (loss of pigment in areas of skin causing milk-white patches)

Abnormal Conditions (cont’d.)

vitiligo

Vitiligo—Loss of pigment in areas of skin.

What is tinea? (fungal infection of skin or nails i.e. ringworm, athlete’s foot)
What is vitiligo? (loss of pigment in areas of skin causing milk-white patches)

Chapter 16
Lesson 16.3

Skin Neoplasms (Benign)

Callus

Keloid

What is a callus? (increased growth of cells in keratin layer of epidermis due to friction against skin)
What is a keloid? (hypertrophied, thickened scar after trauma or surgery)
Ask for student examples of places that commonly develop calluses. Why?
Some people who are prone to keloids are discouraged from having their ears pierced.

Skin Neoplasms (Benign) (cont’d.)

Keratosis: thickened area of epidermis
Leukoplakia: white thickened patches on tongue or cheek
Nevus: pigmented lesion
Verruca: warts caused by virus

Have students find images for abnormalities not shown in the text. Images are very useful for remembering these conditions.

Skin Neoplasms (Cancerous)

Basal cell carcinoma

Malignant tumor of the basal cell layer of the epidermis

Refer back to the chapter that included AIDS.
Why are AIDS patients susceptible to this condition?
Why does it rarely occur in the rest of the population?

Skin Neoplasms (Cancerous)

Malignant tumor of the squamous epithelial cells of the epidermis.

Squamous cell carcinoma

Refer back to the chapter that included AIDS.
Why are AIDS patients susceptible to this condition?
Why does it rarely occur in the rest of the population?

The ABCDEs of malignant melanoma.

A. Asymmetry

B. Border, irregular or circumscribed

D. Diameter, usually larger than 6mm

C. Color variation

Skin Neoplasms (Cancerous) (cont’d.)

These skin tumors often metastasize to the lung, liver, bone, and brain. What is the current treatment for this type of cancer?
Squamous cells can grow wherever there is squamous epithelium (internal or external). Common places include the mouth, larynx, bladder, esophagus, and lungs. Some are cigarette-related.
Why are healthy organs lined with squamous cells in the first place? What about this tissue makes it appropriate for those particular organ systems?

Skin Neoplasms (Cancerous)

Malignant, vascular, neoplastic growth characterized by cutaneous nodules.

Kaposi sarcoma

Refer back to the chapter that included AIDS.
Why are AIDS patients susceptible to this condition?
Why does it rarely occur in the rest of the population?

Laboratory Tests

Bacterial analyses: pus or fluid

samples examined to detect

microorganisms

Fungal tests: scrapings for culture and

microscopic examination after

treatment with KOH.

Clinical Procedures

Cryosurgery: destroy tissue with

subzero temperatures using liquid

nitrogen

Curettage: scrape lesion with sharp

curet

Electrodesiccation: destroy tissue by

burning with electric spark

For what conditions is electrodesiccation recommended?

Clinical Procedures (cont’d.)

Mohs surgery: remove thin layers of

growth to examine under microscope

(basal and squamous cell)

Skin biopsy: punch and shave to

remove for examination in path lab

Skin test: test reaction of body to

allergen with skin test (scratch or patch tests)

Discuss how some of the surgeries are for both diagnosis and treatment. Removal is done whether or not the physician knows that the lesion is cancerous.
All suspicious-looking tissues removed from the body are sent to the pathology lab for analysis. Why?

ABCDE asymmetry, border, color, diameter, evolution — characteristics associated with skin cancer.
bx biopsy
DLE discoid lupus erythematosus
PPD purified protein derivative
SLE systemic lupus erythematosus
SC subcutaneous

Abbreviations

Ask students to provide the full terms for these abbreviations.

REVIEW SHEET

COMBINING FORMS

adip/o ___________
albin/o ___________
caus/o ___________
cauter/o ___________
cutane/o ___________
derm/o ___________

Combining Form Meaning

COMBINING FORMS

adip/o fat
albin/o white
caus/o burn, burning
cauter/o heat, burn
cutane/o skin
derm/o skin

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

dermat/o ___________
diaphor/o ___________
erythem/o ___________
erythemat/o ___________
hidr/o ___________
ichthy/o ___________

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

dermat/o skin
diaphor/o profuse sweating
erythem/o redness
erythemat/o redness
hidr/o sweat
ichthy/o scaly, dry

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

kerat/o ___________
leuk/o ___________
lip/o ___________
melan/o ___________
myc/o ___________
onych/o ___________

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

kerat/o hard, horny tissue
leuk/o white
lip/o fat
melan/o black
myc/o fungus
onych/o nail

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

phyt/o ___________
pil/o ___________
py/o ___________
rhythid/o ___________
seb/o ___________
sabace/o ___________
squam/o ___________

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

phyt/o plant
pil/o hair, hair follicle
py/o pus
rhythid/o wrinkle
seb/o sebum
squam/o scale-like

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

steat/o ___________
trich/o ___________
ungu/o ___________
xanth/o ___________
xer/o ___________

Combining Form Meaning

REVIEW SHEET

COMBINING FORMS

steat/o fat
trich/o hair
ungu/o nail
xanth/o yellow
xer/o dry

Combining Form Meaning

REVIEW SHEET

SUFFIXES

-algia ___________
-derma ___________
-esis ___________
-lysis ___________
-ose ___________

Suffix Meaning

REVIEW SHEET

SUFFIXES

-algia pain
-derma skin
-esis condition
-lysis breakdown; separation; destruction; loosening
-ose full of; pertaining to; sugar

Suffix Meaning

REVIEW SHEET

SUFFIXES

-osis ___________
-ous ___________
-plakia ___________
-plasty ___________
-rrhea ___________

Suffix Meaning

REVIEW SHEET

SUFFIXES

-osis condition, usually abnormal
-ous pertaining to
-plakia plaque
-plasty surgical repair
-rrhea flow; discharge

Suffix Meaning

REVIEW SHEET