Unit 3 The Integumentary System: Skin (1)

OUTLINE 3.3 Accessory structures of the skin. 3.3.1 Hair 3.3.2 Glands 3.4 Functions of skin © Copyright Universidad Europea. Todos los derechos reservados ACCESSORY STRUCTURES OF THE SKIN Origin: embryonic epidermis Accessory structures: Hair Nails Sebaceous glands Sweat glands Functions: Hair/...

OUTLINE 3.3 Accessory structures of the skin. 3.3.1 Hair 3.3.2 Glands 3.4 Functions of skin © Copyright Universidad Europea. Todos los derechos reservados ACCESSORY STRUCTURES OF THE SKIN Origin: embryonic epidermis Accessory structures: Hair Nails Sebaceous glands Sweat glands Functions: Hair/Nails: Protection Glands: thermoregulation, protection © Copyright Universidad Europea. Todos los derechos reservados OUTLINE 3.3 Accessory structures of the skin. 3.3.1 Hair 3.3.2 Glands 3.4 Functions of skin © Copyright Universidad Europea. Todos los derechos reservados HAIR § Wide distribution (except palm and sole surface and heels). Structure: three concentric layers: ØMedulla (with pigment granules) ØCortex ØCuticle (heavily keratinized) SHAFT- visible ROOT– within dermis-hypodermis HAIR FOLLICLE (surrounds the root) • Epithelial root sheath. • Dermal root sheath . Hair regeneration from the hair bulb (enlargement at the base). Function: protection and sensorial (root hair plexus) © Copyright Universidad Europea. Todos los derechos reservados HAIR § Wide distribution (except palm and sole surface and heels). Germinal layer of cells from stratum basale © Copyright Universidad Europea. Todos los derechos reservados Areolar connective tissue HAIR § Wide distribution (except palm and sole surface and heels). Sensory nerves: touch Smooth muscle in dermis that contracts with cold or fear. Extends from superficial dermis – dermal root sheath “goosebumps” © Copyright Universidad Europea. Todos los derechos reservados