Unit 3 The Integumentary System Skin PDF

STRUCTURE OF THE DERMIS § Connective tissue. Cells: fibroblasts, macrophages and adipose cells. - Extracellular matrix : Collagen: resistance. Elastic fibers: flexibility. Ground surface: GAGs. •Function: structural, immunological, mechanical protection, homeostasis control (thermoregulation, water...

STRUCTURE OF THE DERMIS § Connective tissue. Cells: fibroblasts, macrophages and adipose cells. - Extracellular matrix : Collagen: resistance. Elastic fibers: flexibility. Ground surface: GAGs. •Function: structural, immunological, mechanical protection, homeostasis control (thermoregulation, water retention) Blood vessels (deep & superficial) Hair follicles. Sebaceous glands, sweat glands. Nerve endings © Copyright Universidad Europea. Todos los derechos reservados DETECTING SENSATIONS through your skin Free nerve terminals and corpuscular receptors FINE touch; localization of the stimulus FINE touch; localization of the stimulus Vibration Vibration CRUDE touch; non localized stimulus Stretch of skin, Sustained pressure - Mechanoreceptors - Thermoreceptors - Nociceptors (pain receptors) - Proprioceptors (receptors of position) © Copyright Universidad Europea. Todos los derechos reservados Functions of Mechanoreceptors Mnemonic: The superficial receptors detect touch and the deep receptors detect pressure. Meissner is smooth to pronounce – found on smooth skin and detects smooth (fine) touch. Merkel is harder to pronounce – found also on hairy skin and detects crude touch. ViP STaR Vibration: Pacinian corpuscle Stretch and Temperature (warm): Ruffini endings Krause bulb = Kelvin = Kold (Cold) © Copyright Universidad Europea. Todos los derechos reservados 38 DETECTING SENSATIONS through your skin Mechanoreceptors: pressure, vibrations and texture © Copyright Universidad Europea. Todos los derechos reservados © Copyright Universidad Europea. Todos los derechos reservados OUTLINE 3.2 Structure of the skin 3.2.1. Epidermis 3.2.1.1 Cells 3.2.1.2 Layers: thin and thick skin 3.2.1.3 Growth and keratinization of the epidermis 3.2.2. Dermis 3.2.2.1 Structure 3.2.2.2 Papillary region 3.2.2.3 Reticular region © Copyright Universidad Europea. Todos los derechos reservados DERMIS: PAPILLARY REGION § Areolar connective tissue (thin collagen and fine elastic fibers) 20% of dermis- Close to epidermis Structure: Pilous follicles (scarce). Sebaceous and sweat glands (ducts). Free nerve endings (pain, warmth, coolness, tickling, itching). Fine touch receptors. Hair Arrector pili muscle Pore Sebaceous glands Epidermis Krause corpuscle Dermis Free nerve terminals Ruffini corpuscle Fat layer Meissner corpuscle © Copyright Universidad Europea. Todos los derechos reservados Pacinian corpuscle DERMIS: PAPILLARY REGION DERMAL PAPILLAE ØIncrease contact surface between dermis and epidermis (stratum basale). ØInterdigitations into the epidermis form epidermal ridges. ØContains capillaries: nutrition of the epidermis. ØContains corpuscular receptors (mechanoreceptors: Meissner corpuscles) and free nerve endings (pain, burn, itching). © Copyright Universidad Europea. Todos los derechos reservados OUTLINE 3.2 Structure of the skin 3.2.1. Epidermis 3.2.1.1 Cells 3.2.1.2 Layers: thin and thick skin 3.2.1.3 Growth and keratinization of the epidermis 3.2.2. Dermis 3.2.2.1 Structure 3.2.2.2 Papillary region 3.2.2.3 Reticular region © Copyright Universidad Europea. Todos los derechos reservados DERMIS: RETICULAR REGION DENSE IRREGULAR CONNECTIVE TISSUE •Thick collagen fibers (resistance) and elastic fibers (elasticity) •Sweat and oil glands, pilous follicles, Pacinian corpuscles, adipocytes and fibroblasts. •Function: provides resistance, extensibility and elasticity. © Copyright Universidad Europea. Todos los derechos reservados DERMIS: INFOGRAPHICS © Copyright Universidad Europea. Todos los derechos reservados