1. The Integumentary System A. Skin 1. Anatomy 1. Anatomy 2. Physiology 2. Physiology 3. Epidermis 3. Epidermis 4. Dermis 4. Dermis B. Glands B. Glands 1. Sebaceous (oil) glands 1. Sebaceous (oil) glands 2. Sudoriferous (sweat) glands 2. Sudoriferous (sweat) glands a. Eccrine a. Eccrine b. Apocrine b. Apocrine C. Thermoregulation: C. Thermoregulation: homeostasis of body temperature homeostasis of body temperature

2. Cells Tissues Organs System Integumentary System- Skin, hair, nails, glands, and enamel of teeth

3. Integumentary System 1. epidermis 2. dermis 3. derivatives _______________ 4. hypodermis

4. Skin Has 7 Functions 1. regulation of body temperature 2. protection 3. sensation 4. excretion 5. immunity 6. blood reservoir 7. synthesis of vitamin D

5. Epidermis 1. keratinized stratified squamous epithelium 2. four main cell types: a. keratinocytes (90%) a. keratinocytes (90%) b. melanocytes (about 8%) b. melanocytes (about 8%) c. Langerhans cells (1%) c. Langerhans cells (1%) d. Merkel cells (1%) d. Merkel cells (1%)

6. Epidermal Layers 1. stratum basale 2. stratum spinosum 3. stratum granulosum 4. stratum lucidum 5. stratum corneum ___________________ keratinizing system Thick Skin

7. Keratinizing System Mitotic zone-keratinocyte stem Cells, melanocytes and Merkel cells. 8-10 rows-derived from Keratinocytes below- receive Melanin. 3-5 rows-begin producing keratohyalin 3-5 rows of clear, dead cells packed With eleidin-keratin intermediate 25-30 rows of fat dead cells filled with keratin Keratin gives skin a waterproof, anti-microbial, and abrasion-resistant barrier Thick skin only

8. EPIDERMAL LAYERS (the keratinizing system) exfoliation keratin eleidin keratohyalin thick skin stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basalemitosis keratinization cell death dermis

9. The House Dust Mite- Dermatophagoides

10. Dermis 1. papillary 2. reticular ____________functions Loose areolar tissue Dense irregular Elasticity, Extensibility, And Thermoregulation

11. Skin Glands (eccrine) Axillary region, pubic, breasts, Beards in men. Viscous milky Fluid-no odor Sebum Secretion Combines with Sweat forms Acid mantle Most Common 90% water Thermo- regulation 1.Sebaceous (oil) glands 2. Sudoriferous (sweat) glands a. merocrine (eccrine) b. apocrine

12. Protective Functions of the Epidermis 1. acid mantle 2. role of keratin 3. role of the stratum corneum 4. role of the stratum granulosum

13. Thermoregulation 1. homeotherms vs poikilotherms 2. arterio-venous (AV) plexuses AV plexus

14. BODY TEMPERATURE CONTROL CONTROLLED CONDITION A stimulus or stress disrupts homeostasis by causing an increase in body temperature RECEPTOR Thermoreceptors in skin and hypothalamus are activated and send nerve impulses to the control center CONTROL CENTER Hypothalamic control center sends nerve impulses to sweat glands and skin blood vessels EFFECTORS 1.Increased sweat output 2.blood vessels vasodilate, bringing heat to body surface end RETURN TO HOMEOSTASIS Evaporation of sweat from skin removes body heat, thus lowering body temperature and mechanism turns off negative feedback