Chapter 4: Integumentary System

1. Chapter 4: Integumentary System

2. Entry Task 1/7 Brainstorm AND record 3 possible functions of the integumentary (skin) system…

3. Wednesday 1/7 • Mini-Quiz: Body Tissues • Begin CH 4: Skin & Body Membranes • Worksheet: Skin Structure • Take notes from PowerPoint • Integumentary System • Function Melanin • p.108-114

4. Skin & Body Membranes • Epithelial tissue membrane (3 types) • Cutaneous • Stratified squamous on a layer of dense fibrous connective tissue • Mucous • Stratified squamous on simple columnar • Serous • Simple squamous on areolar tissue

5. A Closer Look at the Serosa… • Parietal layer • lines ventral cavity, folds on itself to form visceral layer • Visceral layer • covers outside of organs in cavity • Serous fluid fills the pocket

6. The Serosa

7. Skin & Body Membranes, cont… • Connective tissue membranes • Synovial • Soft areolar connective tissue • NO epithelial cells

8. Functions of I.S. • Protects from: • Mechanical, chemical, bacterial, UV, thermal, & dessication • Heat loss/retention • Excretion of urea/uric acid • Makes Vitamin D • Tells us about external environment

9. Structure • Epidermis • Stratified squamous • Dermis • Dense fibrous conn. tissue • Hypodermis • Adipose tissue Firmly connected together!

10. Skin Structure

11. Epidermis • 5 layers called “strata” (deep to superficial) • stratum basale • stratum spinosum • stratum granulosum • stratum lucidum • stratum corneum • Avascular—no blood supply • Keratinocytes—produce keratin

12. Epidermis of Thick Skin

13. A Closer Look at the Strata… • Stratum basale • deepest layer • receives nutrients • constantly dividing • Stratum spinosum • Stratum granulosum • Cells become flatter, full of keratin • Stratum lucidum • Cells beginning to die, extra thick, hairless skin • Stratum corneum • DEAD!!! • 20-30 cell layers thick

14. Fun Facts • Every 25-45 days, you have a completely NEW epidermis! • Everything you see when you look at someone else is DEAD! Gross!

15. Melanin • Melanin is a pigment • yellow to brown to black • Melanocytes make the pigment • Freckles/moles • Melanin is concentrated in 1 area

16. Dermis • Your dermis is your “hide” • Strong, stretchy envelope • Dense fibrous conn. tissue • Collagen • Elastic fibers • 2 Regions: • Papillary layer—upper dermis • House pain receptors/free nerve endings & touch receptors (Meissner’s corpuscles) • Reticular layer—deepest skin layer • Pressure receptors (Pacinian corpuscles)

17. Dermis, continued… • Blood Vessels—maintain homeostasis • Rich nerve supply

18. Entry Task 1/8 • Explain the function of the stratum basale of the epidermal layer. • Why do we get wrinkled, saggy skin as we age? Be sure to identify the layer of skin involved in your answer. • What part of skin do you think pain receptors are found in? Touch receptors?

19. Tuesday 3/25 Explore the function of cutaneous receptors through a series of lab activities! • Review Entry Task • Complete Cutaneous Receptors lab activity! HW: Read p. 116-124

20. Wednesday 3/26 • Finish “Cutaneous Receptors” Activity • Activity: Make a Sweat Map! • PowerPoint covering p.116-124 • Take notes!!!

21. Skin Color • 3 Pigments • Melanin • Carotene • Oxygen-rich hemoglobin • Alterations in skin color • redness/erythema • pallor/blanching • jaundice • bruises

22. Appendages of the Skin • Includes: • cutaneous glands, hair, hair follicles, and nails • Exocrine glands—release secretions through ducts • 2 Types • Sebaceous glands (oil) • Sudoriferous glands (sweat)

23. Sebaceous Glands (Oil) • All over skin (not on palms/feet) • Empties into hair follicles • Secretes sebum—oil & fragmented cells • Keeps skin soft • Has chemicals that kill bacteria • Clogged duct = whitehead

24. Sudoriferous Glands (sweat) • 2.5 million/person • 2 Types: Eccrine & Apocrine • Eccrine • More common, produces sweat • Heat regulation • 7L sweat on a hot day!

25. Sudoriferous Glands, cont… • Apocrine • Mainly in axillary & genital area • Larger than eccrine glands • Secretes fatty acid/protein along with other components • Bacteria have a hay day!!!

26. Hair & Hair Follicles • Components: • Follicle: produces hair • Shaft: part of hair exposed to environment • Root: part of hair enclosed in the follicle • Medulla: central core • Cortex: area between medulla & cuticle • Cuticle: heavily keratinized; shingles • Arrector pili: smooth muscle, connects follicle to tissue • Matrix: growth zone • Hair bulb: contain melanocytes

28. Nails • Components: • Free edge • Body • Root: embedded in skin • Nail folds: sides of nails, connected to skin • Cuticle: thick proximal nail fold • Lanula: crescent • Nail bed: extends beneath the nail • Nail matrix: thick part of nail bed; growth

30. Homeostatic Imbalances • Over 1000 ailments of the skin! • Mostly allergies, fungus, burns, & cancer • Athlete’s foot—fungus • Boils/carbuncles—inflamed oil glands • Cold sores—herpes virus • Contact dermatitis—chemical contact • Impetigo—bacterial infection • Psoriasis—autoimmune disorder

32. Burns • Def: Tissue damage/cell death caused by intense heat • Skin = thick as a paper towel • Almost all body systems suffer when skin is burned • 2 life threatening problems: fluid loss & kidney shutdown/circulatory shock

33. Burns, cont… • Rule of Nines: • Body divided into 11 areas, each covering 9% surface area • Helps determine volume of fluid lost • Infection is leading cause of death • Burns are sterile 24 hours after • Then pathogens invade

35. Burn Classification • 1° Burn • Epidermis damaged • Red, swollen • Lasts 2-3 days • EX: sunburn

36. Burn Classification • 2° Burn • Epidermis & Upper Dermis damaged • Red, painful blisters • Regrowth can occur • No permanent scarring if taken care of

37. Burn Classification • 3° Burn • Entire thickness of skin destroyed • Blanched/Black • No pain—nerves destroyed • Regeneration not possible • Skin grafting

38. Burn Classification • CRITICAL burns meet this criteria: • 25+% of the body has 2° burns • 10% has 3° burns • 3° burns on the face, hands, and/or feet

39. Skin Cancer • Most common of all cancers • 1 in 5 people will have skin cancer in their lifetime • 3 Types • Basal cell carcinoma • Squamous cell carcinoma • Malignant melanoma

40. Basal Cell Carcinoma • Least malignant, most common • No keratin/boundary formed by stratum basale • Invades dermis/hypodermis • On face, shiny, slow-growing • Full cure @ 99% in most cases

41. Squamous Cell Carcinoma • Stratum spinosum • Scaly, reddened papule • Shallow ulcer, raised border • Scalp, ears, hands, lips • Fast growing • If caught early full recovery can be made

42. Malignant Melanoma • Cancer of melanocytes • 5+% cases are melanoma • Appears spontaneously, develops from pigmented moles • brown to black patches • 50% survival rate

43. ABCD Rule • Asymmetry • 2 sides of mole/spot don’t match • Border irregularity • Borders not smooth, have indents • Color • Different colors, range from black/brown/tan, blues/reds • Diameter • 6+ mm

44. Thursday 3/27 • Finish PowerPoint Notes • Begin Review assignment • P.127 MC: #1-2, 4, 6-7; SA: #1-4, 6-11, 13; At the Clinic: #1-4 Identify different types of burns and skin cancers

45. Friday 3/28 • Correct Review • Play Flyswatter Review game • Test over all of CH 4 on Monday after break! Have a Great Spring Break!