The Integumentary System

1. The Integumentary System Ch. 6

2. Objectives • Identify various parts of the integument • Know the functions of the integumentary system • Know the structural composition of hair and nails • Understand how skin disorders like cancer and burns are classified and what occurs during these disorders

3. The Integumentary System • Includes the skin (integument) and the accessory organs found within the skin

4. Skin: Integumentary System • Functions: prevent dehydration, protect from injury, serve as defense against microorganisms, regulate body temperature, make vitamin D, provide sensation, nonverbal communication • Structure: • Epidermis: outer layer, stratified squamous epithelial cells, no blood vessels, specialized keratinocytes and melanocytes • Dermis: deeper layer, support tissues, fibers

5. Skin: Integumentary System

6. Epidermis • Keratinized stratified squamous epithelium • Cell types • Regenerative stem cells • Keratinocytes • Melanocytes • Tactile cells • Dendritic cells

7. Layers of the Epidermis • From deep out • Stratum basale • Stratum spinosum • Stratum granulosum • Keratohyaline granules • filaggrin • Lamellated granules • Stratum lucidum • Thick skin only • Stratum corneum pgbeautygroomingscience.com

8. Skin Histology nku.edu

9. Skin Color • Melanin • The more produced, the darker the color • Hemoglobin • Reddish – pink skin tones • Carotene • Yellow hue to skin • Concentrates in stratum corneum

10. Diagnostic Abnormal Skin Color • Cyanosis • Skin has a blue appearance • Due to lack of oxygenated blood • Albinism • Lack of melanin • Results from inheritance of nonfunctional tyrosinase • Jaundice • Yellowing of skin and whites of eyes • Due to the inefficient removal of bilirubin • Hematoma • Bruise • Mass of clotted blood • Erythema • Abnormal redness of the skin sciencephoto.com

11. Skin Markings • Friction ridges • Flexion lines • Freckles and moles • Melanocyte aggregates • Hemangiomas • Benign blood capillary tumors skinsight.com

12. Dermis • Connective tissue layer deep to the epidermis • Attached to the epidermis via dermal papillae • Interlocking arrangement with epidermal ridges • Two layers • Papillary • Areolar • Reticular • Dense irregular

13. Accessory Structures of Dermis • Hair: shaft, follicle • Smooth muscle: attached to hair follicle, raises hair to upright position • Oil glands/sebaceous glands: secretion moistens and softens skin

14. Accessory Structures of Dermis (cont.) • Sweat glands: secrete sweat, help in temperature regulation • Apocrine and merocrine • Blood vessels: supply nutrients, remove waste, assist in temperature regulation • Sensory nerve endings: for heat, cold, touch, deep pressure, vibration

15. Dermis healthguide.howstuffworks.com

16. Hypodermis • Binds skin to underlying tissue • Functions as padding and insulation • Subcutaneous fat • Readily absorbs drugs given by hypodermic injection • Highly vascular

17. Hair • Pili (sing. Pilus) are composed of hard, dead keratinized cells • Grow from a follicle that is typically found in the dermis • Hair divided into three zones • Bulb which lies in the follicle • Root • Shaft keratin.com

18. Nails • Scale-like modifications of the epidermis (startum corneum) • Dead cells full of parallel hard keratin emedicinehealth.com

19. Skin Disorders • Skin Cancer • One of the most prevalent cancers • UV radiation damages cells • Three types • Basal cell carcinoma • Most common, stratum basale • Squamous cell carcinoma • Stratum spinosum • Malignant melanoma • Most deadly, melanocytes metrohealth.org

20. Burns • Classified based on depth of tissue involvement • First degree • Epidermis • Red, slight swelling • Second degree • Epidermis and into part of the dermis • Red to white, more painful • Regeneration of epidermis possible • Third degree • Full-thickness, completely through dermis and beyond • Tan to brown, danger of fluid loss and infection • Generally require skin grafts to replace dermis and epidermis burn-recovery.org