Bell Ringer What is the purpose of the skin? How many layers are there in the skin? Crash Course Video Question What is the acronym used for the 5 layers of the epidermis?

The Integumentary System A&P Fall 2016

I. Epithelial Membranes Cutaneous Membrane A.K.A. The Skin Composed of stratified squamous epithelium

B. Mucous Membranes Lines open body cavities a. “Open” means to the outside of the body b. ex. respiratory, digestive, urinary and reproductive organs 2. Composed of various epithelium

b. Serous fluid fills the space between layers C. Serous Membranes 1. Lines closed body cavities 2. Composed of simple squamous epithelium a. Membrane folds over to form two layers Parietal layer- lines the body cavity Visceral layer- covers the organs b. Serous fluid fills the space between layers

II. Functions of the Integumentary System Protection Insulates and cushions organs Protection from many types of damage Mechanical Chemical Thermal UV Bacteria

B. Water Control 1. Skin is full of Keratin and is hardened a B. Water Control 1. Skin is full of Keratin and is hardened a. prevents water loss from body surface C. Temperature control 1. Skin is rich with capillary networks and sweat glands a. helps regulate heat loss from body surface

Bell Ringer What type of membrane covers closed body cavities? What fills the space between the parietal and visceral layers? How many layers of the skin are there?

III. Structure of the Skin Epidermis 1. Composed of 5 Stratum layers a. Corneum b. Lucidum (thick skin only) c. Granulosum d. Spinosum e. Basale

2. Most cells are Keratinocytes a. Produce Keratin i. fibrous protein b. cells become keratinized and die as they move up through the layers

3. Melanocytes are also present a. found mostly in the basale layer b 3. Melanocytes are also present a. found mostly in the basale layer b. produce a pigment called melanin i. gives skin its color ii. Sun exposure causes more melanin production iii. Protects the DNA in cells from UV damage

4. Dendritic cells are scattered throughout a 4. Dendritic cells are scattered throughout a. Alert and activate the immune system

Bell Ringer 1. Which layer of the epidermis is NOT found in thin skin? 2. What type of cells activate the immune system? 3. What type of membrane covers closed body cavities? 4. What fills the space between the parietal and visceral layers? 5. What types of damage does our skin protect us from?

B. Dermis 1. Composed of 2 regions of dense connective tissue a B. Dermis 1. Composed of 2 regions of dense connective tissue a. collagen fibers i. give skin its toughness ii. Keep skin hydrated b. elastic fibers i. give skin its elasticity c. nerve receptors

2. Papillary layer a. peglike projections called papillae b. contain blood capillaries i. provides nourishment for the epidermis c. cause ridged patterns on the epithelial surface (fingerprints)

3. Reticular layer a. many components i. blood vessels ii. Sweat and oil glands iii. Lamellar corpuscles (pressure receptors) b. Phagocytic cells kill bacteria

IV. Skin Color 3 pigments contribute Melanin Depends on amount and type in the epidermis Three types Yellow Reddish brown black

2. Carotene a. Can be deposited in the stratum corneum b. Orange-yellow pigment i. Found in carrots 3. Oxygen-rich hemoglobin 1. Pigment in red blood cells 2. Found in the dermal blood vessels

Emotions can also have an influence Erythema a. Reddened skin b. blushing Blanching a. Becoming pale b. Emotional stress

3. Jaundice a. Yellow skin b. Liver disorder 4. Bruises a. Black and blue marks i. Called hemotomas b. Clotted blood in tissues

Bell Ringer What part of the dermis produces fingerprints? Name 2 things that can change skin color (other than pigments)

V. Appendages of the Skin Cutaneous Glands Sebaceous (Oil) Glands Found everywhere except palms and soles Usually empty into a hair follicle Keeps the skin soft and moist Contains a chemical that kills bacteria

2. Sweat Glands (Two types) a. Eccrine Glands i. found all over body ii. Sweat secreted through pores iii. Helps regulate body temperature b. Apocrine Glands i. found mostly in the axillary and gential areas ii. Sweat secreted into hair follicles iii. Precise function not yet known

B Hair and Hair Follicles 1. Hairs a. A flexible epithelial structure b. produced by a hair follicle i. the part enclosed by the follicle is the root ii. Part projecting from the skin is the shaft c. 3 parts i. Medulla- central core ii. Cortex- bulky surrounding layer iii. Cuticle- outermost layer

Bell Ringer 1. What are the two types of sweat glands? 2. Which one is only found in the axillary and genital areas? 3. What are the 3 parts of hair?

2. Hair Follices a. Two parts i. Epithelial Root Sheath (inner) ii 2. Hair Follices a. Two parts i. Epithelial Root Sheath (inner) ii. Fibrous Sheath (outer); composed of dermal connective tissue

C. Nails a. Scalelike modification of the epidermis b. 3 parts i C. Nails a. Scalelike modification of the epidermis b. 3 parts i. free edge ii. Body iii. Root c. Made mostly of nonliving materials

VI. Homeostatic Imbalances of Skin A. Burns 1. First Degree Burns a. Epidermis damaged b. Area becomes red and swollen i. ex. Sun burn

2. Second Degree Burns a. Epidermis and upper dermis damaged b. blisters appear

3. Third Degree Burns a. Epidermis and dermis completely destroyed b. area is blanched or charred c. skin grafting required

B. Infections and Allergies 1. Athlete’s foot a B. Infections and Allergies 1. Athlete’s foot a. itchy, red, peeling skin between toes b. caused by fungus infection

2. Boils and Carbuncles a. inflammation of hair follicles & oil glands b. carbuncles caused by bacterial infection i. typically staphylococcus

3. Cold Sores a. small fluid filled blisters i 3. Cold Sores a. small fluid filled blisters i. usually around the lips and inside the mouth b. caused by Herpes Simplex virus

4. Contact Dermatitis a. itching, red, swollen skin forms blisters b. allergic reaction to chemicals i. ex. Poison Ivy/Oak

5. Impetigo a. pink, water-filled, raised lesions around the mouth and nose i. develop yellow crust and rupture b. caused by highly contagious staphylococcus c. common in elementary aged kids

6. Psoriasis a. red lesions covered with dry scales i. itch, burn, crack and bleed b. caused by overproduction of skin cells i. possibly an autoimmune disorder

C. Skin Cancer 1. Basal Cell Carcinoma a. most common b C. Skin Cancer 1. Basal Cell Carcinoma a. most common b. stratum basale cells don’t produce keratin and invade dermis c. usually cured with surgical removal

2. Squamous Cell Carcinoma a. occur in stratum spinosum b. grows rapidly c. can be cured with surgical removal or radiation therapy

3. Malignant Melanoma a. cancer of melanocytes b. rare but deadly c. sunbathers should follow ABCD rule i. Asymmetry- two sides of colored spot do not match ii. Border irregularity- borders are not smooth iii. Color- spot contains different colors iv. Diameter- larger than 6 mm in diameter (pencil eraser)