the integumentary system - linn–benton community...

10/1/2016

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The Integumentary System

The Integumentary System

• Organ system that protects the body from various kinds

of damage

• Examples: water loss, abrasion

• Includes skin and its derivatives

• Hair

• Nails

• Glands

• Sebaceous

• Sudoriferous

• Ceruminous

• Scales, feathers, hooves in other animals

Structure of the Skin

• One of the body’s largest organs

• 2 main layers

• Epidermis

• Dermis

Copyright © 2010 Pearson Education, Inc. Figure 5.1

Epidermis

Hair shaft

DermisReticular

layer

Papillary

layer

Hypodermis

(superficial fascia)

Dermal papillae

Pore

Subpapillary

vascular plexus

Appendages

of skin

• Eccrine sweat

gland• Arrector pili

muscle• Sebaceous

(oil) gland• Hair follicle• Hair rootNervous structures

• Sensory nerve fiber

• Pacinian corpuscle

• Hair follicle receptor

(root hair plexus)

Cutaneous vascular

plexusAdipose tissue


• Epidermis

• 4-5 main layers

• Stratum corneum

• Surface layer, dead cells

• Keratin

• Stratum germinativum

• Dividing cells

• Melanin


Epidermis

Hair shaft

DermisReticular

layer

Papillary

layer

Hypodermis


Dermal papillae

Pore

Subpapillary

vascular plexus

Appendages

of skin

• Eccrine sweat


muscle• Sebaceous





(root hair plexus)

Cutaneous vascular


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• Dermis

• Deep to epidermis

• Contains

• Connective tissue

• Nerve endings

• Blood vessels

• Hair follicles

• Skin glands

• Hypodermis


Epidermis

Hair shaft

DermisReticular

layer

Papillary

layer

Hypodermis


Dermal papillae

Pore

Subpapillary

vascular plexus

Appendages

of skin

• Eccrine sweat


muscle• Sebaceous





(root hair plexus)

Cutaneous vascular



• Epidermis and dermis are attached to each other with varying

degrees of strength


• Epidermal derivatives

• Hair

• Structure

• Root

• Shaft

• Follicle

• Pigments

• Melanin = ranges of colors = yellow/red, brown, black

• Gray = lack of pigment

• Carotene = yellowish


Epidermis

Hair shaft

DermisReticular

layer

Papillary

layer

Hypodermis


Dermal papillae

Pore

Subpapillary

vascular plexus

Appendages

of skin

• Eccrine sweat


muscle• Sebaceous





(root hair plexus)

Cutaneous vascular




• Hair cont.

• Functions

• Insulation

• Protection

• Sensation

• Psychosocial

• Nails

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• Glands

• Sebaceous

• Associated with hair follicles

• Secrete oil

• Fats, cholesterol, proteins, salts

• Functions



• Glands

• Sudoriferous

• Tubular glands, numerous on palms and soles

• Secrete sweat

• Water, salts, urea, uric acid, amino acids, lactic

acid, ascorbic acid

• Functions



• Glands

• Ceruminous

• Secrete ear wax

• Modified sweat glands

• Functions

Functions of the Skin

• Sensation

• Protection

• Chemical, physical/mechanical, biological

• Excretion

• Vitamin D production

• Temperature regulation


Sweat glands activated

Shivering

begins

StimulusBody temperature

risesBALANCE

Information sent

along the afferent

pathway to control

center

Information sent

along the afferent

pathway to control

center

Afferent

pathway

Afferent

pathway

Efferent

pathway

Efferent

pathway

Information sent

along the efferent

pathway to

effectors

Information sent

along the efferent

pathway to effectors

StimulusBody temperature falls

Receptors

Temperature-sensitive

cells in skin and brain

Receptors

Temperature-sensitive

cells in skin and brain

Effectors

Sweat glands

Effectors

Skeletal muscles

Control Center

(thermoregulatory

center in brain)

Control Center

(thermoregulatory

center in brain)

Response

Evaporation of sweat

Body temperature falls;

stimulus ends

Response

Body temperature rises;

stimulus ends

Skin Disorders

• Color can be an important indicator of health

• Pigmentation

• Paleness/redness

• Cyanosis

• Jaundice

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Skin Diseases

• Acne

• Impetigo

• Psoriasis

• Decubitus ulcers

• Sunburn

• Skin cancer

• Basal cell carcinoma

• Squamous cell carcinoma

• Melanoma

• Systemic lupus erythematosis

• Warts

Acne

• Hair follicles plug with oil and dead skin cells

• May become infected and inflammed

• Influenced by a number of factors (hormones, stress, etc)

Impetigo

• Highly contagious skin infection

• Caused by Staphylococcus aureus

• Common in young children

• Blisters or sores usually appear on face, neck, hands, and

diaper area

Psoriasis

• Buildup of skin cells due to overdivision

• Dry, scaly, itchy patches

• Thought to be an immune system problem

• Genetic, but attacks are triggered by infection, stress, and cold

Decubitus ulcers (bedsores)

• Skin injury resulting from prolonged pressure

• Pressure on one side + bone on the other = lack of blood flow

• Develop quickly, hard to treat, slow to heal (easier to prevent)

• Common in those with limited mobility

Sunburn

• Damage to skin from overexposure to UV light

• Peeling = body’s attempt to shed damaged cells

• Damage to blood vessels underneath = increased blood flow

and warmth

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Cancer

Basal cell carcinoma

Malignant melanoma

• Uncontrolled cell growth due to genetic changes

• Cells may metastasize and spread to other areas of the body

Burns

• Causes

• Heat

• Chemicals

• Electricity

• Radiation

• Dangers

• Fluid and plasma protein loss → shock

• Infection

• Circulation

• Kidney damage

• Scarring

Burns

• Classification

• Rule of nines

• Treatment

Surface area percentage reference

This illustrates the difference between infants and adults

Burns

• First degree

• Epidermal damage only

• Localized redness and pain

• Second degree

• Epidermal and upper

dermal damage

• Blistering, edema and pain

Copyright © 2010 Pearson Education, Inc. Figure 5.10a

(a) Skin bearing partial

thickness burn (1st and

2nd degree burns)

1st degree

burn

2nd degree

burn

Burns

• Third degree

• Entire thickness of skin damaged

• Gray-white, cherry red, or black

• No initial edema or pain (nerve endings destroyed)

• Skin grafting usually necessary

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Burns

• Critical if:

• >25% of the body has second-degree burns or worse

• >10% of the body has third-degree burns

• Face, hands, or feet have third-degree burns


Anterior and posteriorhead and neck, 9%

41/2%41/2%

Anterior and posteriorupper limbs, 18%

Anterior and posteriorlower limbs, 36%

100%

Totals

Anterior and posteriortrunk, 36%

Anterior

trunk,

18%

9% 9%(Perineum, 1%)

41/2%

Burns

• Treatment

• Cleaning and debridement

• Fluid therapy

• Protection

• Grafting

• Prevention of infection

• May require very high calorie and high protein diet

Burns

• Treatment

Skin: Developmental Aspects

• Advanced age

• Decreased blood flow to skin

• Thinning of epidermis

• Loss of subcutaneous fat

• Less collagen and elastin

• Fewer melanocytes

• Gray hair

• Reduced glandular activity

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