6.2 Accessory Structures of the Skin Sponge: Set up Cornell Notes on pg. 31 Topic: 6.2 Accessory Structures of the skin Essential Question: What is the major function of the accessory structures of the skin? Text: 176-180 6.2 Accessory Structures of the Skin 2.1 Atoms, Ions, and Molecules What is the major function of the accessory structures of the skin? Get both papers from tray

Homework Children die after being left in hot cars ONLY ANSWER Questions 4-8 HL answers to questions as you read

Objective Students will understand the functions of the accessory structures of the skin Students will create a tree-map comparing the functions of each type of accessory structure

Clinical Application 6.2/6.3 Read Clinical Application 6.2/6.3 and answer the questions HIGHLIGHT the answers to the questions in the reading as a way to provide evidence for your answer

Clinical Application 6.3 Acne Vulgaris Most common skin disorder Sebum and epithelial cells clog glands Produces whiteheads and blackheads anaerobic bacteria trigger inflammation (pimple) Largely hormonally induced Androgens stimulate sebum production Treatments include antibiotics, topical creams, birth control pills

Accessory Structures of the Skin Accessory Structures of the skin originate from hair follicles As long as accessory structures remain intact, severely burned or injured dermis can regenerate

Hair Follicles and Hair Pg. 31 Accessory Structures of the Skin Hair Follicles and Hair Nails Glands

Hair Follicles + Hair Hair follicles: Composed of living epidermal cells Hair follicles present on MOST skin surfaces Everywhere EXCEPT: Palms/soles/lips/nipples/parts of reproductive organs Hair: Composed of dead epidermal cells

Hair Color Genes determine hair color Based on amount of melanin that melanocytes produce

Hair Loss We lose from 20-100 hairs a day Baldness: occurs when lost hair is not replaced Genetic X linked gene More frequent in males Look at your mother’s father. Is he bald? That may be your fate. 

Functions of Hair With your table: Hypothesize what the function of each type of hair is. Hair’s Functions: Protection Warmth Touch Sense Eyelashes and Eyebrows: Protect eyes from dirt, sweat, rain etc. Hair on head: Protection from sun Hair in nose/ears: Keep foreign objects out

Nails Nails: Protective coverings on fingers and toes Specialized epidermal cells Mirror health Bluish= circulation problem Horizontal furrows= period of serious illness/malnutrition Certain disorders may lead to extreme curvature of the nails Ex: Cystic Fibrosis

Extreme curvature Bluish Horizontal Furrows

Sebaceous Glands Sebaceous glands: Produce sebum (oil), which is secreted into follicles through ducts Keep skin and hair soft and waterproof Acne results from excess sebum secretion

Sweat Glands Sweat glands: are widespread in skin Mostly water Some salt Some waste Two types: Eccrine Apocrine

Eccrine sweat glands: Most numerous Respond primarily to temperature change Also in palms/soles and release sweat when emotionally distressed Apocrine glands- develop a scent as they are metabolized by skin bacteria Become active @ puberty Also active during sexual arousal

Integumentary System: Crash Course A+P 9m18s 15 bullets on p. 36 https://www.youtube.com/watch?v=EN-x-zXXVwQ

Children Die After Being Left in Hot Cars Directions: Read the article. HIGHLIGHT the answers to these questions as a way to “prove” your answer. Use article to answer 4-8 Don’t answer 1-3 until tomorrow’s notes DUE TOMORROW

With your table: Hypothesize the differences between human and chimp hair. Human Hair vs Chimp Hair Appearances can be deceiving! We have the same amount of hair per square inch as a chimpanzee Our hair is just shorter, thinner, and lighter

Lanugo (La-new-go) and Hypertrichosis (Hyper-trick-o-sis) Babies are covered with lanugo while in the womb, some babies are born with a thin layer still visible In a very rare disorder called hypertrichosis- the lanugo remains and grows long

Lose the fur….loose the parasites Our hair persisted in places where our individual scents cling “Parasite-reduction hypothesis” Fur entraps fleas, lice and ticks Which spread diseases Lose the fur….loose the parasites