Medical assisting Administrative and clinical procedures (5e) Chapter 23 The integumentary system

After completing this chapter, you will be able to: List the functions of skin, explain the role of skin in regulating body temperature, describe the layers of skin and the characteristics of each layer, explain the factors that affect skin color, list the accessory organs of skin and describe their structures and functions.

The Integumentary

System

Learning Outcomes (cont.)

23.1 Describe the functions of skin

23.2 Describe the layers of skin and the

characteristics of each layer

23.3 Explain the factors that affect skin color

23.4 Summarize types of common skin

lesions.

Learning Outcomes (cont.)

23.5 Describe the accessory organs of skin

along with their structures and functions

23.6 Explain the process of skin healing,

including scar production

23.7 Describe the common diseases and

disorders of the skin.

Functions of the Integumentary System

Functions of the Integumentary System

(cont.)

• Body temperature regulation

– If too hot

• Dermal blood vessels dilate

• More blood to surface so heat escapes– If too cold

• Dermal blood vessels constrict

• Prevents heat from escaping

Functions of the Integumentary System

(cont.)

• Vitamin D production

– Skin must have sunlight

– Needed for calcium absorption

• Sensation – receptors

• Excretion – perspiration

Apply Your Knowledge

What are the functions of the integumentary

system?

ANSWER: The functions of the integumentary system

are protection, regulation of body temperature, vitamin D

production, sensation, and excretion.

Epidermis (cont.)

• Cell types

– Keratinocyte

• Most common

• Makes and accumulates the protein keratin

– Melanocyte ~ makes the pigment melanin

• Deeper, more complex

• Contains all major tissues, plus

– Sudoriferous glands

– Sebaceous glands

– Hair follicles and arrector pili muscles

– Collagen, elastin, and nerve fibers

– Blood vessels

To Figure of Skin

Subcutaneous Layer

• Hypodermis

• Composed of

– Adipose (fat) and loose connective tissue

– Blood vessels and nerves

To Figure of Skin

Apply Your Knowledge

What are the layers of skin and what is their

function?

ANSWER:

Epidermis – superficial outer layer; cells produce keratin

which makes it waterproof and resistant to bacteria and

viruses; and melanin which absorbs UV radiation.

Dermis – most complex layer; contains all major tissue

types; binds epidermis to subcutaneous tissue

Subcutaneous layer – inner most layer of adipose and

loose connective tissue; the adipose cushions and

insulates underlying structures and organs.

Skin Color (cont.)

• Oxygenated blood

– Oxygen dissolved in the hemoglobin of the red blood

cells– Well-oxygenated blood ~ pink skin

– Poorly oxygenated blood ~ pale or bluish skin

Apply Your Knowledge

What affects skin color?

ANSWER: The amount of melanin produced by the melanocytes and the oxygenation of the blood.

tumor

Skin Lesions (cont.)

• Primary – originate from disease or body

changes

• Secondary – reaction to external trauma

• Vascular – anomalies of blood vessels

Skin Lesions (cont.)

Lesion Name Description

Bulla A large blister or cluster of blisters

Cicatrix A scar, usually inside a wound or

tissue Crust Dried blood or pus on the skin

Ecchymosis A black-and-blue mark or bruise

Erosion A shallow area of skin worn away

by friction or pressure

Skin Lesions (cont.)

Lesion Name Description

Excoriation A scratch; may be covered with

dried blood Fissure A crack in the skin’s surface

Keloid An overgrowth of scar tissue

Macule A flat skin discoloration, such as a

freckle or a flat mole Nodule A large pimple or small node

Skin Lesions (cont.)

Lesion Name Description

Papule An elevated mass similar to but

smaller than a nodule Petechiae Pinpoint skin hemorrhages that

result from bleeding disorders Plaque A small, flat, scaly area of skin

Purpura Purple-red bruises usually due to

clotting abnormalities Pustule An elevated (infected) lesion

containing pus

Skin Lesions (cont.)

Lesion Name Description

Scale Thin plaques of epithelial tissue on

skin’s surface Tumor A swelling of abnormal tissue

growth Ulcer A wound that results from tissue

loss Vesicle A blister

Wheal Another term for hive

Apply Your Knowledge

Match the following:

_ Keloid A A blister

_ Vesicle B A crack in the skin’s surface

_ Crust C An overgrowth of scar tissue

_ Fissure D A small, flat scaly area of skin

_ Ulcer E Dried blood or pus on the skin

_ Plaque F A wound that results from tissue loss

Accessory Organs

• Hair follicles

– Tube-like depressions in the dermis of skin

– Generate hairs

– Alopecia – follicles die

– Arrector pili ~ muscles that pull on follicles

Diagram

Accessory Organs (cont.)

glands

– Produce sebum to keep hair soft

– Prevent bacteria from growing on skin

Diagram

Accessory Organs

• Nails

– Protect the ends of

fingers and toes– Epithelial cells with

hard keratin– Nail body

– Nail root

– Lunula

– Nail bed

Apply Your Knowledge

tube-like depressions in the

skin’s dermis; generate hairs baldness

produce watery type of sweat muscles attached to hair

follicles; cause “goose bumps”

produce sweat produce sebum keeps hair soft and pliable protect the ends of fingers and

toes become active during puberty

ANSWER:

A B

C

D

E

F G

H I

Perfect!

Skin Healing (cont.)

• Inflammation promotes healing

– Extra blood to area

– Extra nutrients

– Defensive cells

Injury occurs

Injury occurs

Blood clot forms

Blood clot forms

Clotted blood and other dried tissue

Scab replaces blood clot

Scab replaces blood clot

Binds the edges of wound; scar may form

Collagen fibers replace

scab

Collagen fibers replace

scab

Apply Your Knowledge

How does inflammation promote healing of the

skin?

ANSWER: Inflammation promotes healing by

bringing extra blood, nutrients for skin repair, and

defensive cells to the area of injury

Common Diseases and Disorders of the

Skin

• Burns

– Extent of body surface area and degree of a burn

– Rule of nines is used to determine extent of burn

• Estimate body surface area

• 11 body areas

4½% 4½%

Perineum 1%

Anterior legs

and feet 18%

Posterior legs and feet 18%

Anterior trunk

18%

Posterior trunk and buttocks 18%

Back

– Always requires medical attention

Burns

Burns (cont.)

• General guidelines for treatment

– Do not remove anything sticking to the burn

– Do not apply butter, lotions, or ointments

– Cool with large amounts of water

Burns (cont.)

• General guidelines for treatment

– Cover with sterile sheet or plastic bag

– Contact emergency services

– Check airways for swelling

Skin Cancer and Common Skin Disorders

• Skin – vulnerable due to exposure

Skin Cancer and Common Skin

Disorders (cont.)

• Basal Cell

– Signs / symptoms

• Growth or sore that will not heal

• Waxy, smooth, red, pale, flat, or lumpy– Treatment

• Curettage and electrodessication

• Mohs surgery

• Cryosurgery

• Laser therapy

Skin Cancer and Common Skin

Disorders (cont.)

• Squamous Cell

– Less common than basal cell

– Flat cells of the epidermis

– Found on face, lips, ears,

and backs of hands– Signs and symptoms and treatments are the same as

for basal cell carcinoma

Skin Cancer and Common Skin

• Chemotherapy and radiation therapy

• Immunotherapy

Skin Cancer and Common Skin

Disorders (cont.)

A symmetry – a mole should not become asymmetrical

B order – a mole should not have irregular borders and

edges should not blur into normal tissue.

C olor – a mole should not change or become mixture

of colors

Skin Cancer and Common Skin

Disorders (cont.)

D iameter – a mole should not grow larger than the

diameter of a pencil eraser (6 mm.)

E volving – a mole that has been changing in size, color

and appearance, or growing in an area of previously normal skin

Skin Cancer and Common Skin

Disorders (cont.)

Stage 0 Only found in epidermis

Stage I Spread to epidermis and dermis (1 to 2 mm

thick)Stage II 2 to 4 mm thick and may be ulcerated

Stage III Spread to one or more nearby lymph nodes

Stage IV Spread to other body organs or lymph nodes

far from original melanoma

Stages of

Melanoma

Stages of

Melanoma

Common Skin and Hair Disorders

• Dermatitis

– Inflammation of skin

or a rash– Eczema ~ chronic dermatitis

• Folliculitis

– Swimmer’s rash– Inflammation of hair follicles

Common Skin Disorders (cont.)

– Vaccine

Common Skin Disorders (cont.)

• Impetigo

– Oozing skin lesions

that eventually crust over

– Highly contagious

• Pediculosis

– Capitus ~ head lice– Corporis ~ body lice– Pubis ~ pubic lice

• Psoriasis – chronic, inflammatory skin condition

Common Skin Disorders (cont.)

Common Skin Disorders (cont.)

• Warts

– Harmless growths caused by a virus – Vary in appearance – OTC medications

Apply Your Knowledge

1 True or False:

_ Basal cell carcinoma is the most aggressive form of skin

cancer and can form anywhere

_ Squamous cell carcinoma is more likely to spread to

surrounding tissues

_ Lesions of melanoma appear on trunk, head, neck of

men and on arms and legs of women

_ The borders of skin cancers are usually regular

_ Basal cell carcinoma progresses slowly and rarely

spreads to other body parts

Melanomas are more aggressive.

Borders are irregular.

Apply Your Knowledge

2 Using Figure for Rule of Nines,

determine burn extent for a

patient who has burns to his

anterior face and both arms.

Click for Rule of Nines

In Summary

23.1 The functions of skin include: protection, body

temperature regulation, vitamin D production, sensation, and excretion

23.2 The topmost layer of the skin is the epidermis The

dermis is the complex middle layer The innermost layer attaching the skin to muscle is the subcutaneous layer

23.3 The amount of melanin affects and determines

skin color The amount of oxygen-carrying hemoglobin in the blood also affects skin color

In Summary (cont.)

23.4 Skin lesions are split among three main types:

primary lesions such as macules and vesicles;

secondary lesions, which include ulcers and keloids; and vascular lesions, which involve blood

vessels and include telangiectasias and

ecchymoses

23.5 The accessory organs of skin include: hair

follicles, arrector pili muscles, sebaceous glands,

sudoriferous glands, and keratin-filled nails.

In Summary (cont.)

23.6 Injured skin becomes inflamed from dilating

blood vessels that leak and cause swelling A

blood clot is formed, which is replaced by a

scab, which is then replaced by collagen fibers

that produce scar tissue

23.7 Common diseases and disorders of the skin

include alopecia, cellulitis, dermatitis, eczema,

folliculitis, herpes simplex, herpes zoster, impetigo,

pedicuosis, psoriasis, ringworm, rosacea, scabies,

and warts.

We may have different religions, different

languages, different colored skin, but we all belong to one

human race.

End of Chapter 23