1. Integumentary system

3. Organization – Skin Epidermis Dermis – Accessory Structures Hair & Hair follicles Exocrine glands Arrector pili Sensory Receptors

4. Layers beneath the skin – Subcutaneous layer – Deep fascia ________________________

5. Functions of the Skin – Protection – Water-resistance – Temperature regulation – Vitamin D synthesis – Sensations – Immunity – Social signaling

6. –Stratum Germinativum Stem cells Melanocytes Merkel cells  The Epidermis

8. – S. Spinosum “Pre-keratinocytes” Melanocytes Langerhans cells  The Epidermis

10. – S. Granulosum – S. Lucida Keratinocytes in both layers  The Epidermis

11. – S. Corneum Dead keratinocytes  The Epidermis

12. Skin cell-eating mite

13.  The Dermis

14. Reticular layer – Dense irregular CT – Provides strength and elasticity

15.  The Dermis Papillary layer – Areolar CT – Contains cap’s and sensory neurons for epidermis – Arranged as dermal papillae –

16. Perform secretory functions Perform transport functions Maintain physical integrity Ciliated epithelia move materials across their surface Specializations of epithelium

17. The Polarity of Epithelial Cells

18. Cells attach via cell adhesion molecules (CAM) Cells attach at specialized cell junctions –Tight junctions –Desmosomes –Gap junctions Maintaining the integrity of epithelium

19. Intercellular connections Animation: check tutorials

20. Basal lamina attaches to underlying surface –Lamina lucida –Lamina densa Germinative cells replace short-lived epithelial cells Structure of typical epithelium

21. Number of cell layers –Simple –Stratified Shape of apical surface cells –Squamous –Cuboidal –Columnar Classification of epithelia

22. Squamous Epithelia

23. Cuboidal Epithelia

25. Transitional Epithelium

26. Columnar Epithelia

30.  Pigmentation Melanin Carotene Hemoglobin

31.  Epidermal Derivatives Hair Follicles and Hair Skin Glands

32.  Hair Function – Protection – Touch Sensation Structure – Root – Shaft – Bulb

33.  Hair Hair Follicle – Sheath of epithelial cells – Surrounds root – Merges with bulb

35.  Hair Associated structures – Dermal papilla – Sebaceous glands – Arrector pili

36.  Hair Growth Cycle – 2-5 yrs: growth stage – 2 yrs: resting stage

37.  Skin Glands Sebaceous glands – secrete sebum – help to protect hair and skin

38.  Skin Glands Merocrine (eccrine) sweat glands – BT control – excretion – protection

39.  Skin Glands Apocrine sweat glands – Secrete pheromones?

40.  Skin Glands Mammary glands Ceruminous glands

41.  Skin Sensory Receptors Free nerve endings Pacinian corpuscles Meissner’s corpuslces

42. Lines of Cleavage