chapter 3 skin structures and diseases Flashcards
what is the largest organ of the body?
skin
dermatology definition
medical branch of science that deals with the study of skin. its nature, structure, functions, diseases and treatment
dermatologist definition
physician engaged in the practice of treating the skin, including its structures functions and diseases.
integumentary system definition
organ system consisting of the hair, skin, nails and exocrine glands.
what does the skin do?
protects the network of muscles, bones, nerves, blood vessels and everything else inside our bodies. thinnest around eyes and eyelids and thickets on hands and soles of feet.
what is healthy skin? SB
slightly moist, soft, flexible with a textured feel and appearance that is ideally smooth and fine grained.
surface of healthy skin is what?
slightly acidic and its immune responses react quickly to microscopic organisms that touch or try to enter it.
appendages of the skin include what?
hair, nails, sweat and oil glands.
as a nail tech what must you be able to do?
recognize adverse conditions such as irritated or inflamed skin, disease, and infectious skin disorders.
callus definition
repeated pressure on any part of the skin, prevents damage, must not be fully removed or it can cause injury or possible infection.
skin is composed of how many layers?
3 ( epidermis, dermis, subcutaneous tissue/hypo dermis)
epidermis definition
outermost and thinnest layer of the skin. does not contain blood vessels, reliant on dermis for nutrition for continuous cell renewal, has 5 layers, stratum is Latin for layer, outermost top layer of our epidermis is the stratum corneum and its visible to the eye and the part the beauty practitioner cares for.
stratum corneum
also called horny layer. first line of defense against foreign substances and antigens such as uv rays, pollution, allergens, viruses, bacteria and undesirable topicals. asses ones level of photo damage, skin type, and any abnormal skin conditions by examining this layer. has scale like cells that are continually being shed and replaced by others that are constantly rising to the surface.
keratin definition
a fibrous protein that is also the principle component of hair and nails.
keratinization definition
chemical conversion of living cells into dead cells. skin renewal process takes 25-28 days depending on general info of person. keratinization cells combine with lipids/fats, salts, minerals, and water that are produced by glands in the skin. makes up the outer layer of skin known as the barrier function or acid mantel. protective and water resistant.
stratum lucidum definition
clear, transparent layer just under the skins surface; consists of small oval shaped cells in which light can pass. most abundant in palms of hands and soles of feet. thicker areas have ridges that give our palms and soles traction through friction so we don’t slip or drop anything. finger print swirls are dependent on this layer to form
stratum granulosom
or grainy layer consist of cells that look like small distinct granules. cells are dying as they are pushed to the surface and will eventually replace the stratum corneum or dead skin cells as they are shed from skin surface layer. tiny desmosomes from residual fingerlike protrusions that were broken away from outter layer of spinosum cells cobine with the granule cells. they then become part of the intercellular cement that holds all skin layers together. process of keratinization is created here.
stratum spinosum
called spiny layer. just above basal layer ( deepest layer) of the epidermis. as these cells rise to the surface they form desmosomes finger like projections that function like clogs or spot welds between cells. this is where lanerhans cells reside.
langerhans definition
immune support cells. reside in the stratum spinosum and help protect the body from infection by identifying potential harmful substances known as antigens.
stratum germinativum
known as the basal layer. deepest living layer of the epidermis. produces new epidermal skin cells through a process of mitosis to replace keratinized skin cells that are shed from the stratum corneum by daily cleansing and normal or over reactive cellular metabolism.
stratum germinativum
known as the basal layer. deepest living layer of the epidermis. produces new epidermal skin cells through a process of mitosis to replace keratinized skin cells that are shed from the stratum corneum by daily cleansing and normal or over reactive cellular metabolism. special column shaped cells that produce; melanocytes, melanosomes, aka pigmented granules melanin.
what and how should you use sunscreen?
spf 15-30. helps melanin protect sensatice skin cells against uv exposure. help protect from damage against cancer, premature aging.
dermis definition
or true skin is the underlying or inner layer of the skin. also called derma, corium, or cutis. highly sensitive and 25x thicker than the epidermis. within structure there are numerous blood vessels, lymph vessels, nerves, sweat glands, oil glands, hair follicles and arrector papillae muscles. made up of two layers; papillary and deeper reticular layer.
papillary layer definition
upper layer of the dermis located directly underneath the epidermis. find dermal papillae here which are cone shaped elevations containing containing large amounts of gel like substance chemically known as muco-polysaccharides or glucose aminoglycans. this substance makes up a great deal of the reticular dermis below. papillae also contain looped capillary vessels, lymphatic vessels, and small nerve endings called tactile corpuscles and sensitive to touch and pressure. 10-20% accounts for dermis.
reticular layer definition
deepest layer of the dermis and supplies the skin with all of its oxygen and nutrients. major support for the skin is derived from this layer. it is home to the sweat glands, blood vessels, hair follicals, lymph vessels, arrector pili muscles, oil glands, nerve endings, collagen fibroblasts, elastin.
subcutaneous tissue and layer
fatty layer found below the dermis. fat tissue is also called an adipose tissue or subcutis tissue and it varies in thickness depending on persons info. gives smoothness and contour to the body, contains fats that are oil soluble vitamins and hormones, acts as an energy source of food for use as energy, and serves as a protective cushion for the skin and underlying structures.
the skin is covered with endings of the following nerve fibers.
motor nerve fibers; distributed to the arrector pili muscles.
sensory nerve fibers; reacts to heat, cold, pressure, touch, pain. sends messages to brain.
secretory nerve fibers; distributed to the sweat and oil glands of the skin. regulates excretion of perspiration from sweat glands and controls flow of sebum to surface of skin. also part of the autonomic nervous system.
where are nerve endings most abundant in?
fingertips.
skin gets its strength, form, flexibility, from two specific structures composed of flexible protein fibers found within the dermis. collagen and elastin make up 70% of the dermis. definitions next card.
collage- fibrous protein that gives skin form and strength. 16 types through out body. type 1&3 are most abundant in skin. makes up large portion of dermis 70%. help gives structural support to the skin by holding together all structures found in this layer.
elastin- collagen fibers are interwoven with it. Makes up 15% of collagen fibers this fiber gives the skin its flexibility helping it regain its shape even after being repeatedly stretched or expanded. Both fibers are important to the overall health and appearance of the skin.
Skin contains two types of duct glands that extract materials from the blood to form new substances. What are these two?
Sudoriferous glands or sweat glands and the sebaceous glands or oil glands
Sudoriferous sweat glands definition
Consist of a coil base or secretory coil. Along the coils are small ducts that deliver hydration to the skin through cells called aquaporins. Has a tube like duct. Controlled by the nervous system. evaporation of sweat cools the skin surface aka wicking. 1-2 pints of liquid are eliminated daily through sweat pores in the skin.
There are two types of sweat glands in our bodies what are they?
Apocrine glands- are usually associated with our hair follicles, scalp, underarms, and genitals. Secrete a fatty sweat. Are inactive till they are stimulated by hormonal changes in puberty. Can be stimulated by stress and can sometimes create odorous fatty acid.
eccrine glands- MAJOR sweat glands of the skin and found all over. coiled tubular glands that excrete directly to the surface of the skin helping regulate body tempeture and eliminate waste products from the body.
