Largest _________ (21 ft 2 in adult, weighs about 8 lbs) Usually attaches to _________ (exception: flexion creases) Thinnest layer? (0.5mm) _______________.

CHAPTER 5THE INTEGUMENTARY SYSTEM

MISCELLANEOUS

Largest _________ (21 ft2 in adult, weighs about 8 lbs)

Usually attaches to _________ (exception: flexion creases)

Thinnest layer? (0.5mm) _______________ Thickest layer? (4.0mm) _________________

Why a system?

STRUCTURE OF SKIN

Epidermis – stratified ____________; stratum basale (cell __________); stratum corneum (keratinized); Langerhans cells (___________ cells, APCs); melanocytes (roughly ________ # in everyone)

Dermis – loose and ___________connective; dermal papillae epidermal ridges (f_______, surface area); elastin/collagen; blood vessels; receptors for t______, pr________, p_______, and temp.; hair ____________; sweat glands; sebaceous glands (produce _________)

Subcutaneous (Hypodermis) – loose connective and ____________ (insulates; excessive amounts = obesity)

STRUCTURE OF SKIN

EPIDERMIS

Notice all of the bacteria.

Stratum corneum. Notice how the squamous cells form a protective scale-like layer (~15-20 cells thick).

ACCESSORY STRUCTURES (HAIR)

Develops from hair ___________ (cuticle cells of hair and cuticle cells of follicle grow in __________ directions – keeps hair from _________ _______)

Three phases of hair follicle cycling: Anagen – growth (2-8 years; genetically determined) Catagen – transition (2-3 weeks; end of ______; cut

off from ___________ supply) Telogen – rest (about 3 months, then hair _______

out; about 50-150 shed/day) As the hair grows, __________ digest sheath

around hair shaft at skin’s surface Sebaceous gland and arrector ______

ACCESSORY STRUCTURES (HAIR)

Hair

Notice how the cells grow in opposite directions.

Hair Magnified (3:12)

ACCESSORY STRUCTURES (HAIR)

Color of hair is controlled and affected by ________. Albinism is a genetic ___________ that

prevents the production of _____________ within melanocytes.

ACCESSORY STRUCTURES (NAILS)

Nails – nail root; nail bed; nail body (plate); lunula; cuticle; made mostly of k_____________ cells; grow __________ on the hand you use – Why?

Condition of nails can provide clues to underlying ____________ (color, shape, presence of lines on nail body)

What’s the cause of the white spots? Should we worry about them? Will they kill us?!?!

ACCESSORY STRUCTURES (SWEAT GLANDS)

Sweat glands – most concentrated on ____________ (Why?); apocrine (empty into _______ _________); eccrine (empty onto ________ ____________); ceruminous glands (cerumen, wet/dry); mammary glands (modified sweat glands that secrete __________)

FUNCTIONS OF SKIN

Protection from physical ____________ Protection from ___________ invasion Prevents __________ loss/gain Synthesis of vitamin ____ (in presence

of light) Regulation of body __________________

TEMP REGULATION

Heat arises from breakdown of _______ose and ATP (heat is absorbed by __________); vasodilation; vasoconstriction; sweating; contraction of _____________ pili; hyperthermia; hypothermia; fever – benefits?

DISORDERS

Athlete’s foot: _________ infection Impetigo: ____________ infection; usually S.

aureus Furuncles/carbuncles: inflammation of hair

____________ and ________________ glands; ______________ infection; can become severe in people with d___________; S. aureus

Eczema/psoriasis: overactive ______ ___________

Dandruff: increased keratinization Urticaria: hives; ______________ reaction How to become a dermatologist (3:36)

DISORDERS

Athlete’s Foot (fungal infection)

Impetigo (bacterial infection)

Carbuncle in diabetic (bacterial)

Furuncle/boil (bacterial)

DISORDERS

Urticaria/hives (allergic reaction)

Eczema (overactive cell division; skin irritant)

Psoriasis(overactive cell division; genetic)

CANCERS

Melanoma – due to _____; malignant; cancer of ____________; arises from _________; ~8000 deaths per year in US, ~50,000 worldwide

Basal cell carcinoma – due to _____; ___________ tumor in basal cells of epidermis

Squamous cell carcinoma – due to _____; usually ___________; found in ____________ cells of epidermis

Moles – benign overgrowth of melanocytes Warts – not tumors; _________ infection (HPV:

human papillomaviruses - nearly 200 of them; a few are oncoviruses)

Treeman (7:31) Treeman after surgery (1:53)

CANCERS

Melanoma on Skin

Melanoma on the iris

Basal Cell Carcinoma Squamous Cell Carcinoma

Melanoma Animation (3:01)

Melanoma Video (5:04)

MELANOMA SURGERY

Photos courtesy of Josie Harrington, former student

BURNS

1st, 2nd, 3rd, and 4th degree

1st degree

2nd degree

3rd degree

BURNS

Rule of nines Used to

determine the _________ of a burn

Expressed in _____

What is its purpose?

WOUND HEALING

wound clot scab WBC work fibroblasts make new tissue scar

Benefits of a wound-healing medication Wound Healing Process (4

:06)How wounds heal (4:00)

AGING

Dermis thins; epidermis becomes _________; less ___________ in subcutaneous; less collagen and elastin (reduced flexibility); difficulty maintaining temp. _______________; fewer hair __________; less sebaceous glands (cracking due to less __________); fewer ______________ (blotchy pigmentation); gray hair – Why?

Age spots (UV damage)M

eet

Mrs

. Tin

ker!