Integumentary Integumentary SystemSystem

SAP2. Students will analyze SAP2. Students will analyze the interdependence of the the interdependence of the

integumentary, skeletal, andintegumentary, skeletal, andmuscular systems as these muscular systems as these

relate to the protection, relate to the protection, support and movement of support and movement of

thethehuman body.human body.

a. Relate the structure of the a. Relate the structure of the integumentary system to its integumentary system to its functional role in protectingfunctional role in protectingthe body and maintaining the body and maintaining

homeostasis.homeostasis.

EQ: What role does the integumentary EQ: What role does the integumentary system play in protecting the body and system play in protecting the body and maintaining homeostasis? maintaining homeostasis?

Cutaneous MembranesCutaneous Membranes

1)1) Cutaneous – (skin); Cutaneous – (skin); only epithelial only epithelial membrane that is membrane that is drydry

Integumentary SystemIntegumentary System

►Most roles are Most roles are protective protective

►Helps maintain Helps maintain homeostasishomeostasis

► Insulates bodyInsulates body► Keeps water and Keeps water and

molecules in bodymolecules in body► Protects organs from Protects organs from

bumps, cuts, etc.bumps, cuts, etc.

Make-up of epidermisMake-up of epidermis

► Epidermis has no Epidermis has no blood supply blood supply (avascular)(avascular)

►Most cells are Most cells are keratinocyteskeratinocytes Produce keratin Produce keratin

(tough fibers which (tough fibers which make skin tough but make skin tough but pliable) pliable)

Stratum BasaleStratum Basale► Basement membrane of Basement membrane of

epidermisepidermis► VascularizedVascularized► Constantly undergoing Constantly undergoing

mitosis mitosis ► By the time cells reach By the time cells reach

the surface, they are the surface, they are dead.dead.

MelaninMelanin

► Cells in stratum Cells in stratum basale take in basale take in melanocytes (cells melanocytes (cells produce pigment)produce pigment)

►Melanin = body’s Melanin = body’s natural sunscreennatural sunscreen

DermisDermis

► Layer directly Layer directly beneath the beneath the epidermisepidermis

►Highly VascularizedHighly Vascularized

► Connective tissueConnective tissue

Make-up of DermisMake-up of Dermis

►Mostly collagen and Mostly collagen and elastic fiberselastic fibers

► Fibers bind with Fibers bind with water and keep skin water and keep skin hydratedhydrated

► Fibers decrease Fibers decrease with age, and skin with age, and skin sagssags

Deep to the DermisDeep to the Dermis

► Subcutaneous layerSubcutaneous layer Also called Also called

hypodermishypodermis Adipose tissueAdipose tissue Absorbs impact from Absorbs impact from

bumps, protects bumps, protects organs; insulationorgans; insulation

Skin CancerSkin Cancer

►Melanin serves to Melanin serves to protect cellular DNA protect cellular DNA from ultraviolet lightfrom ultraviolet light

►When damage is done When damage is done to DNA, cancer can to DNA, cancer can occuroccur

► Basal Cell carcinoma Basal Cell carcinoma (least malignant)(least malignant)

► Squamous cell Squamous cell carcinomacarcinoma

►Melanoma – darkened Melanoma – darkened blotchesblotches Cancer of the melanocyteCancer of the melanocyte

Papillary LayerPapillary Layer

► Upper dermal Upper dermal regionregion

► Protrusions into Protrusions into epidermis called epidermis called dermal papillaedermal papillae

►Nourishes epidermisNourishes epidermis

Also in Papillary LayerAlso in Papillary Layer

►Meissner’s Meissner’s corpuscles – corpuscles – sensory receptors sensory receptors (touch)(touch)

► Pain receptorsPain receptors

► Papillary pattern is Papillary pattern is genetic, and forms genetic, and forms fingerprintfingerprint

Reticular LayerReticular Layer►Deep to papillary Deep to papillary

layerlayer

► Contains blood Contains blood vessels, sweat vessels, sweat glands and oil glands and oil glands.glands.

► Phagocytes Phagocytes prevent bacterial prevent bacterial intrusionintrusion

Sweat GlandsSweat Glands► Controlled by nervous Controlled by nervous

systemsystem

► Two typesTwo types► 1) Eccrine1) Eccrine► 2)Appocrine 2)Appocrine

Sebaceous GlandsSebaceous Glands

►Oil GlandsOil Glands Ducts usually empty Ducts usually empty

into a hair follicleinto a hair follicle Secretes sebumSecretes sebum Sebum keeps skin Sebum keeps skin

moist and pliablemoist and pliable Also produces acidic Also produces acidic

compounds that kill compounds that kill bacteriabacteria

Problems with oil glandsProblems with oil glands

► Clogged oil gland Clogged oil gland becomes becomes whiteheadwhitehead

► As whitehead As whitehead oxidizes, it oxidizes, it becomes darker becomes darker (blackhead)(blackhead)

► Acne – infection of Acne – infection of oil glandoil gland

► Seborrhea- “cradle Seborrhea- “cradle cap”cap”