Ch. 5 The Integumentary System

1. Ch. 5 The Integumentary System

2. Terms to fill out prior to class • Keratinocytes & functions • Melanocytes & functions • How many and name sub-layers of epidermis • Which sub-layers of epidermis contain living cells • Which sub-layer does mitosis • Which sub-layer is only in palms and soles

3. I. Integumentary System Skin = Cutaneous Membrane • Includes Skin derivatives

4. A. Epidermis Tissue = # layers– depending on location 1. Cells of Epidermis • Keratinocytes: • Melanocytes: • Dendritic (Langerhans’) cells– function = • Tactile (Merkel) cells or Merkel Discs: • Attached to: • Function: • Intercellular junctions:

5. 2. Layers of the Epidermis: a) Stratum basale (basal layer) • Location: • Age of cells: • Mitosis: • Cells Present: • Keratinocytes • Melanocytes • Merkel Disc Figure 5.2b

6. b) Stratum spinosum (Prickle layer) • Appearance: • Cells present: • Keratinocytes • Extensions of Meloanocytes • Langerhans’ cells • numerous Figure 5.2b

7. c) Stratum granulosum (Granular layer) • Thin: • keratinocytes: • Granules: • keratin • Keratohyaline: • Glycolipid: Figure 5.2b

8. d) Stratum lucidum (Clear Layer) • Alive? • A few rows • Contains clear protein • Location: • Function Figure 5.2b

9. e) Stratum Corneum (Horny Layer) • Location: • Thickness: • Functions include: • Waterproofing • Protection: • Keratinized = Cornified • Replaced: Shed everyday and Figure 5.2b

10. 3. Skin ColorMelanin – pigment of skin color • Produced by: • Basic Color: • Also affected by: • Amount depends upon: • Function:

11. Skin Color can indicate Homeostatic ImbalanceSTUDENTS DO • Cyanosis (blue) • Redness • Pallor • Jaundice • Bruises

12. 5.1 …C. Dermis‘hide’ (leather) Overall Components Fibers: Cells: Vessels: Nerves Accessory structures Overall Functions:

13. 1. Dermis: 2 layers a) Papillary layer • Location • Tissue • Dermal papillae • Capillary loops • Mesiners Corpuscles: • Merkel Discs: • Sensory Nerve Endings: • Fingerprints: Epidermal Pegs Reticular Layer Dermal Papillae

14. 1. Dermis: 2 layers … b) Reticular layer • Location • Tissue • Blood vessels • Sweat and oil glands • Pacinian Corpuscles: • Sensory Nerve Endings

15. c) Hypodermis (subcutaneous layer) • Tissue: • blood vessels: • storage site for: • Other functions:

16. II. Accessory Structures of the Skin

17. 5.2 Accessory Structures …A. Hair and Hair Follicles 1. Hair a) Composition: b) Color: c) Hair Parts: • Hair shaft – • Hair root – 2. Hair Follicle = epidermis that lowered into dermis Figure 4.7c

18. 2. Hair Follicle … • a) Wall: 3 layers • b) End Portion = Hair Bulb • Hair Root Plexus: • Hair Matrix: Mitotic cells produce: • Hard Keratin • c) Hair papilla – vascularized dermal CT • Function • 3. Arrectorpili – • NEXT SLIDE  Figure 5.5c

19. 3. Arrector pili … Function =

20. B. HAIR LOSS

21. III. Accessory Structures A. Nails– made of • Function • Sweat Glands • Sudoriferous Glands • Excretion Method: 1. Merocrine(Eccrine) • Open onto skin surface, • most common • locations • Function:

22. C. Sweat Glands … 2. Apocrine • Larger (Lab Model) • Deepest in dermis • Associated with: • Location: • Odor: • Activated at: • Function A axillary  hair puberty  get big larger one

23. 3. Sweat and Its Function • Composition • 99%: • Salts, vitamin C, • Dermicidin = • Some metabolic waste • pH 4-6 usually • Function • heat • waste • Inhibits • For Apocrine:

24. C. Sebaceous Glands – usu. empty into hair follicles • Produce oil – • Location • Method of secretion • activated at: • Functions • Lubricant: • brittle hair • Kills:

25. C. Sebaceous Glands … Plugged sebaceous gland = PIMPLE! Acne = plugged oil glands • Problems with

26. III Functions of the Integumentary System • Protection – • Cutaneous sensation: • Thermoregulation: • Vitamin D Synthesis: • Excretion: Objective: Describe the functions of the skin and the structures that enable them.

27. IV. Diseases, Disorders, and Injuries to skin A. Injuries  Burns = damage from: 1. Results of Severe Burns = Immediate Threat • fluid • electrolyte • Kidneys: • Circulatory Shock • Infections Later • Infections: 2. Rule of 9’s:

28. 3. Severity of Burns • First-degree burns • Layer: • Appearance: • Healing: • Second-degree burns • Layers: • Appearance: • Healing: • Third-degree burns • Layers: • Appearance: • Healing:

29. 4. Critical Burns: • 2nd Degree: > • 3rd Degree: > • OR 3°burns to:

30. B. Disease  Skin Cancer CANCER = • Basal cell carcinoma • Layer: • Danger: • Prevalence: • Squamous cell carcinoma • Layer: • Danger: • Prevalence: • Malignant melanoma • Layer: • Danger: • Prevalence: • Often develop from a:

31. Contributing Factors & Detection • Is there such a thing as a Safe Tan? DETECTION– ABCD Rule: detecting malignant melanoma • A = Asymmetry • B = Border irregularity • C = Color • D = Diameter • E = Elevation

32. END

33. Review Questions 6. The stratum _______ of the epidermis is responsible for producing every other layer of the epidermis and the stratum ________ is composed of dead cells filled with keratin.

34. Dermis …

35. Review Question 2. Describe 2 ways the skin helps to moderate body temperature.

36. Review Questions 3a. Ultimately, all epidermal cells including hair and nail cells come from the __________ layer of the epidermis. 3b. What layer of the skin delivers nutrients to the above mentioned epidermal layer? 2a. Stratum basale 2b. dermis or papillary layer

37. Review Questions 4a. Uncle John tries to jump over a camp fire and trips and falls into the fire. He receives 2nd degree burns to the front and back of his left leg, but not his feet. What percentage of his body is burned? 4b. Are the burns critical? 9% anterior + 9% posterior = 18% Less than 25% 2° = nope, but jumping fires still not recommended