Integumentary: Layers of the skin

Use the drop down word bank to complete the overview paragraph of the Integumentary System. The integumentary system is made of the skin, which is the largest organ in the body, and its accessory structures. The skin acts as a protective barrier between the external and internal environment, defends against infection, prevents dehydration, maintains body temperature, stores water and fat, synthesizes vitamin D and serves as a receptor for pain, pressure, touch and heat.The skin has 3 main layers – the epidermis, the dermis and the hypodermis. The epidermis is made of stratified squamous epithelium. Keratinocytes, found in the epidermis, produce a protein called keratin which makes the skin tough and water-resistant. Other epidermal cells called melanocytes, produce a pigment called melanin which helps protect against damaging UV radiation and is responsible for hair and skin color. Nails and hair are made of keratinized epithelium and are specialized epidermal structures.The dermis contains connective tissue, blood vessels, sebaceous (oil) glands, sweat glands, hair follicles, sensory receptors and nerves. It is located underneath the epidermis. The dermis has 2 main layers – the papillary layer and the reticular layer. The papillary layer contains dermal papillae which form ridges and create each person’s unique fingerprints. Nerves and blood vessels in the papillary layer “feed” the epidermis. The reticular layer contains collagen and elastin fibers to give strength and elasticity to the skin. It contains nerves that help sense pressure and pain. Lastly, the reticular layer contains the cutaneous plexus, the blood vessels extending up from the hypodermis.The hypodermis is the subcutaneous layer of skin. It is a flexible layer of areolar and adipose connective tissue and which stabilizes yet separates the skin from the underlying muscles and bones. It contains major blood vessels that supply the skin. The hypodermis functions as insulation and padding to underlying tissues and organs. macrophages are immune system cells which reside in the hypodermis and gobble up bacteria which may have entered through a wound in the skin. Injections are usually given in this layer as it contains no vital organs. Skin structure Use the word bank to label the anatomy of the skin. Click on the blue dot to type in ONLY THE NUMBER that goes with each label:1 - dermis 7 - sweat gland2 - sebaceous gland 8 - dermal papillae3 - epidermis 9 - hypodermis4 - hair shaft 10 - Pacinian corpuscle (pressure receptor)5 - adipose 11 - hair follicle6 - blood vessels 12 - arrector pili muscle 3 1 9 11 7 5 12 2 4 8 6 10 Epidermis Label the diagram with the correct term:stratum granulosum, stratum corneum, stratum basale, stratum spinosum, stratum lucidum stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale Layers of the Epidermis and Dermis Match the the layers which make-up the epidermis and dermis with their correct description. most inferior epidermal layer; involved in rapid cell division stratum basale major skin layer from which hair and nails arise epidermis as a whole layer that exists only in the thick skin of the palms and soles stratum lucidum scalelike, dead cells full of keratin that constantly flake off stratum corneum binds the epidermis to underlying tissues dermis as a whole layer of dermis responsible for fingerprints; composed of areolar tissue papillary layer layer of dermis which contains collagen and elastin fibers to give strength and elasticity to skin reticular layer middle layer of the epidermis; contains abundant granules stratum granulosum Hair Structure Use the word bank to label the anatomy of the hair. Click on the blue dot to type in ONLY THE NUMBER that goes with each label:1 - hair bulge2 - hair papilla3 - arrector pili muscle4 - hair shaft5 - hair follicle6- hair root 3 1 5 4 6 2 Produce sebum, an oil that covers the skin or hair to provide elasticity and waterproofing sebaceous glands Produce earwax ceruminous glands Produce milk mammary glands These secrete an oil along the hair shaft and are also called “scent glands”. Found around nipples, in axillary and pubic regions. apocrine glands Secrete water and salt (sweat) to lower the body temperature via evaporative cooling. eccrine glands Sweat glands are also called: sudoriferous glands Nail Structure Use the word bank descriptions to label the parts of the nail. Click on the blue dot to type in ONLY THE NUMBER that goes with each label:1 - fold of stratum corneum over the nail base2 - underneath nail plate3 - site of nail growth4 - pale, crescent area of the nail 4 1 2 3 Stages in Wound Repair Match the picture describing each stage to its correct label. Inflammation - mast cells release heparin and histamine; vessels become more permeable so blood can reach the tissues; a scab (blood clot) forms. Proliferation - cells multiply; blood vessels form; fibroblasts migrate to area; granulation tissue forms to fill in wound. Remodeling - blood vessels are resorbed; fibroblasts leave; a scar is formed. Skin Diseases Match each disease with its correct description. Hair follicles which become clogged with dead skin cells acne Most dangerous form of skin cancer; occurs in melanocytes of epidermis melanoma Caused by human papillomavirus (HPV) warts Formation of disrupted collagen when dermis tries to heal itself scar Common skin cancer with highest survival rate; occurs in lowest layer of epidermis squamous cell carcinoma An autoimmune disorder where body mistakenly attacks healthy skin cells; causes scales and rashes psoriasis