Integumentary System PDF - Anatomy and Physiology

University of the East RAMON MAGSAYSAY MEMORIAL MEDICAL CENTER, INC. #64 Aurora Boulevard Doña Imelda, Quezon City, 1113 Telephone No. 8713-3309; 871-0861 local 289 COLLEGE OF NUR...

University of the East RAMON MAGSAYSAY MEMORIAL MEDICAL CENTER, INC. #64 Aurora Boulevard Doña Imelda, Quezon City, 1113 Telephone No. 8713-3309; 871-0861 local 289 COLLEGE OF NURSING Anatomy and Physiology: Module 3 Part 1 Epidermis: Skin Pigments Integumentary System Skin Pigments - 1. Melanin is produced by Layers of the Skin melanocytes in the stratum basale Major layers of the skin - blocks damage from ultraviolet 1. Epidermis - most superficial layer. (UV) rays. 2. Dermis - layer deep to epidermis. - 1.1 Eumelanin (brown-black, most 3. Hypodermis (subcutaneous layer) - common) deep to the dermis. - 1.2 Pheomelanin (red-brown) - 2. Hemoglobin - a red pigment in Epidermis: Cell Types and Layers red blood cells. The Epidermis - 4 Major Types of Cells: - 3. Carotene - a yellow-orange - 1. Keratinocyte pigment stored in the stratum - 2. Melanocyte corneum and adipose tissue. - 3. Langerhans cell - Immune Clinical Connection cells/Macrophages - 1. Albinism - Congenital disorder, - 4. Merkel cell complete or partial absence of Types of Skin pigment in the skin, hair, and eyes - Thin Skin (hairy): covers all body due to a defect of an enzyme regions except the palms, palmar involved in the production of surfaces of digits, and soles. melanin. - Thick Skin (hairless): Covers the - 2. Vitiligo - Chronic disorder, palms, palmar surfaces of digits, causes depigmentation patches in and soles. the skin, precise cause unknown, The Epidermis but most likely an autoimmune - The epidermis is composed of 4 disease that attacks melanocytes. layers in thin skin and 5 layers in thick skin. Dermis and Hypodermis - 1. Stratum Basale - 1 layer, Close The Dermis - subdivided into 2 regions: to the dermis, Melanocytes. Papillary - 2. Stratum Spinosum - 8-10 layers, - Superficial portion of dermis (about Dermal layer, Keratinocytes. one-fifth) - 3. Stratum Granulosum - 3-5 - Consists of areolar connective layers, Keratinocytes, Far to the tissue with thin collagen and fine dermis. elastic fibers. - 4. Stratum Lucidum - 4-6 layers, - Contain dermal ridges that house Appears clear, Flattened blood capillaries, corpuscles of Keratinocytes. touch, and free nerve endings. - 5. Stratum Corneum - Up to 50 Reticular layers, Dead cells, Being replaced - Deeper portion of dermis (about by cells below. four-fifths) - Consists of dense, irregular connective tissue with bundles of  thick collagen and some coarse - 2. Regression stage - matrix stops elastic fibers. dividing. - Spaces between fibers contain - 3. Resting stage - follicle is at rest. some adipose cells, hair follicles, - 4. Reactivation of hair matrix nerves, sebaceous glands, and Types of Hair sudoriferous glands. - 1. Lanugo - fine unpigmented layer The Hypodermis - below the dermis and is of hair that covers the fetus. not a part of the skin. - 2. Terminal - long, coarse, heavily 4 Types of Skin Glands pigmented hair. 1. Sebaceous Glands - Connected to - 3. Vellus - Short, fine, pale hair that hair follicles. replaces lanugo after birth. 2. Eccrine Glands - Located mainly in Hair Color hairy skin areas. - Hair color is primarily due to the 3. Apocrine Sweat Glands - Located amount and type of melanin mainly in hairy skin areas. present in the keratinized cells of 4. Ceruminous Glands - Modified the hair. sweat glands located in the ear - 1. Eumelanin (Black hair) canal. - 2. Pheomelanin (Blonde hair) - 3. Decreased Melanin (Aging) Hair - Accessory Structures of the Skin - 4. No Melanin + air bubbles (Old) - Present on most body surfaces except palms and palmar surfaces Functions of the Skin of fingers/soles and plantar - Has 6 main functions: surfaces of the feet. 1. Thermoregulation - Composed of dead keratinized - Sweat epidermal cells. - Blood flow to the dermis - Genetic and hormonal influences 2. Blood Reservoir determine the thickness and - The dermis has so many blood distribution of our hair. vessels that it can hold about The Parts of a Hair 8-10% of total blood flow while an - 1. Shaft - above the skin surface. adult is at rest. - 2. Root - below the level of the 3. Protection skin. - Blocking bacteria, etc., from going - 3. Follicle - surrounds the root. inside the body. - 4. Epithelial root - extension of - Uses Keratin, Lipids, Sebum, epidermis. Acidic sweat, Melanin, - 5. Dermal root sheath - dermis Macrophages. surrounds the follicle. 4. Cutaneous Sensations - 6. Hair bulb - onion shaped - The skin contains different sensory - 7. Hair matrix - derived from receptors found in different layers: stratum basale, responsible for hair - Tactile sensations - touch, growth. pressure, vibration, tickle. - 8. Hair papilla - indentation in bulb - Thermal sensations - warm, cool. where blood vessels nourish - Pain matrix. 5. Excretion and Absorption Hair Growth Stages - Excretion - elimination of - 1. Growth stage - hair grows out of substances from the body. the matrix.  - Absorption - passage of materials Burns from the external environment into - A burn is tissue damage caused by body cells. excessive heat, electricity, 6. Synthesis of Vitamin D radioactivity, or corrosive - UV rays activate the precursor chemicals that denature (break molecule that allows vitamin D to down) the proteins in the skin cells. be made. - Burns are graded according to - Vitamin D aids in the absorption of their severity. calcium from foods in the - 1. First Degree Burn: Epidermis gastrointestinal tract. - 2. Second Degree Burn: Epidermis Epidermal Wound Healing and Dermis - Superficial wounds only affect the - 3. Third Degree Burn: Epidermis, epidermis. Dermis, and Subcutaneous. - Stratum basale starts rebuilding - The Rule of Nines wound closes. - The rule of nines is used to - Cells divide and replace the estimate the surface area of an original area of epidermis - adult affected by a burn. thickening. Pressure Ulcers Wound Healing - With age, there is an increased - Injury extends into the dermis and susceptibility to pressure ulcers subcutaneous layer: (‘bed sores’). - 1. Hemostasis - Constriction of - When shedding of epithelium blood vessels, formation of blood caused by a deficiency of blood clot. flow to tissues occurs, pressure - 2. Inflammatory response - Dilation ulcers can develop. of blood vessels in the area, recruitment of immune cells and platelets. - Migration of epithelial cells towards each other, growth/thickening of epithelium, return to normal. Skin Cancer, Burns, and Pressure Ulcers 3 Major Types of Skin Cancer - Excessive exposure to ultraviolet light (from the sun or tanning salons) is the most common cause of skin cancer. - 1. Basal Cell Carcinoma - 2. Squamous Cell Carcinoma - 3. Malignant Melanoma Benign Moles vs Cancerous Moles - Asymmetry - Borders - Color - Diameter - Evolving