Due in Lab

1. Skeletal System 33-34

2. Skeletal System 26

3. PreLab 6

Due next week in lab - Scientific America Article

• Select one article to read and complete article summary

• Cell Defenses and the Sunshine Vitamin (Summary in Case Study 19-20)

• Skin Deep (Summary in Case Study 21-22)

• Sex and the Secret Nerve (Instructor website)

• The Naked Truth (Instructor website)

The Integumentary System

Copyright © 2010 Pearson Education, Inc. Figure 5.1

Epidermis

Hair shaft

Dermis Reticular

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 root Nervous structures

• Sensory nerve fiber

• Pacinian corpuscle

• Hair follicle receptor

(root hair plexus)

Cutaneous vascular

plexus Adipose tissue

Structure of the Skin

• One of the body’s largest organs

• 2 main layers

• Epidermis

• Dermis

• Derivatives

• Hair

• Nails

• Glands

• Sebaceous

• Sudoriferous

• Ceruminous

Structure of the Skin

• Epidermis

• 4-5 main layers

• Stratum corneum

• Surface layer, dead cells

• Stratum germinativum

• Dividing cells

• Melanin

Copyright © 2010 Pearson Education, Inc. Figure 5.1

Epidermis

Hair shaft

Dermis Reticular

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 root Nervous structures

• Sensory nerve fiber

• Pacinian corpuscle

• Hair follicle receptor

(root hair plexus)

Cutaneous vascular

plexus Adipose tissue

Structure of the Skin

• Dermis

• Deep to epidermis

• Contains

• Connective tissue

• Nerve endings

• Blood vessels

• Hair follicles

• Skin glands

• Hypodermis

Copyright © 2010 Pearson Education, Inc. Figure 5.1

Epidermis

Hair shaft

Dermis Reticular

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 root Nervous structures

• Sensory nerve fiber

• Pacinian corpuscle

• Hair follicle receptor

(root hair plexus)

Cutaneous vascular

plexus Adipose tissue

Structure of the Skin • Epidermal derivatives

• Hair

• Structure

• Root

• Shaft

• Follicle

• Pigments

• Melanin, brown, yellow

• Gray?

Copyright © 2010 Pearson Education, Inc. Figure 5.1

Epidermis

Hair shaft

Dermis Reticular

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 root Nervous structures

• Sensory nerve fiber

• Pacinian corpuscle

• Hair follicle receptor

(root hair plexus)

Cutaneous vascular

plexus Adipose tissue

Structure of the Skin • Epidermal derivatives

• Hair cont.

• Functions

• Insulation

• Protection

• Sensation

• Psychosocial

• Nails

Structure of the Skin • Epidermal derivatives

• Glands

• Sebaceous

• Associated with hair follicles

• Secrete oil

• Fats, cholesterol, proteins, salts

• Functions

Structure of the Skin • Epidermal derivatives

• Glands

• Sudoriferous

• Tubular glands, numerous on palms and soles

• Secrete sweat

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

• Functions

Structure of the Skin • Epidermal derivatives

• Glands

• Ceruminous

• Secrete ear wax

• Functions

Functions of the Skin

• Sensation

• Protection

• Chemical, physical/mechanical, biological

• Excretion

• Vitamin D production

• Temperature regulation

Copyright © 2010 Pearson Education, Inc. Figure 1.5

Sweat glands activated

Shivering

begins

Stimulus

Body temperature

rises BALANCE

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

Stimulus

Body 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

Addison’s disease

Jaundice

Cyanosis

Skin Diseases

• Acne

• Impetigo

• Psoriasis

• Decubitus ulcers

• Sunburn

• Skin cancer

• Basal cell carcinoma

• Squamous cell carcinoma

• Melanoma

• Systemic lupus erythematosis

• Warts

Acne

Impetigo

Psoriasis

Decubitus ulcers

Sunburn

Cancer

Basal cell carcinoma

Malignant melanoma

Burns

• Causes

• Heat

• Chemicals

• Electricity

• Radiation

• Dangers

• Fluid and plasma protein loss → shock

• Infection

• Circulation

• Kidney damage

• Scarring

Burns

• Classification

• Rule of nines

• Treatment

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

Copyright © 2010 Pearson Education, Inc. Figure 5.10b

(b) Skin bearing full

thickness burn

(3rd degree burn)

3rd

degree

burn

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

Copyright © 2010 Pearson Education, Inc. Figure 5.9

Anterior and posterior

head and neck, 9%

4 1 / 2 % 4 1 / 2 %

Anterior and posterior

upper limbs, 18%

Anterior and posterior

lower limbs, 36% 100%

Totals

Anterior and posterior

trunk, 36%

Anterior

trunk,

18%

9% 9% (Perineum, 1%)

4 1 / 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