Overviews_Exam3-1

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Chapter Overviews – Exam #3 Chapter 6 1. List the general functions of the integumentary system. Protection, thermoregulation, sensation detection, synthesis of vitamin D and excretion/ absorption 2. Draw, label and describe the structure of the epidermis. Superficial to Deep* Stratum corneum - thick layer of dead keratinocytes that protect from friction damage. Stratum lucidum - thick skin (palms/soles), large amount of keratin and thickened membranes. Stratum granulosum -lamellar granules secrete lipid rich products that act as water replant and sealant, keratohyalin converts keratin intermediate filaments into keratin. Stratum spinosum - contain intraepidermal macrophages and projections of melanocytes, held together by desmosomes, older cells generate keratin from cytoplasmic protein and start collapsing(squamous) Stratum Basale - deepest layer, continually producing new keratinocytes, bound by desmosomes, bound to basement membrane by hemidesmosomes, contain keratin intermediate filaments, melanocytes, and tactile epithelial cells. 3. Draw, label and describe the structure – and function(s) -- of the various parts of the dermis, including the accessory glands and hair follicles . Papillary region - closest to epidermis, rippled into dermal papillae (Fingers) that stabilize the epidermis and create epidermal or friction ridges where they are highest (fingerprints) makes up 20% of the dermis. Reticular region - basic structure is dense irregular connective tissue (strength and flexibility) contains bundles of thick collagen, scattered fibroblasts, macrophages, adipocytes and coarse elastic fibers are in the deepest parts. Embedded with blood vessels, nerves, glands and hair follicles. Essential to the survival of the epidermis. Epidermal ridges -increase surface area Hair- UV light protection, heat loss and debris trapping Arrector pili muscle - contraction straightens the normally ‘flat’ follicle so the shaft ‘stands up’. Hair root plexus - sensory neuron dendrites wrapped around the follicle to detected hair shaft movement. Sudoriferous glands (sweat)- Eccrine glands - thermoregulating sweat. Apocrine glands - oily secretion with pheromones Sebaceous glands (sebum)(holocrine)- associated with hair follicles, secretes a sticky, antibacterial substance for infection protection and to prevent dehydration of hair shaft and skin. Ceruminous glands - modified apocrine sweat glands in the external ear canal to protect and lubricate the tympanic membrane. Secretion mixes with dead keratinocytes and creates a waxy cerumen. Mammary glands - modified apocrine glands that produce milk

Lacrimal glands - exocrine glands in the eyes that protect them. Ciliary glands - apocrine glands found next to the base of the eyelashes and keeps eyelashes from drying out. 4. Describe the various chemicals that affect skin tone/coloration. What causes changes from “normal” for each type? a. Describe how body temperature can affect perceived skin tone. melanin is the main factor for skin tone. Melanin comes in 2 forms: eumelanin (dark) and pheomelanin (reddish). Skin tone is based on the rate and type of melanin secretion, not the number of melanocytes. UV light exposure increases production. Albinism is the inability to produce melanin. Carotene is a yellowish-orangish hydrophobic molecule that’s stored in the subcutaneous adipose tissue. (question- which came first… the carrot or carotene? :D) hemoglobin is a red color when bound to O2 or CO and can affect the redness/ color of the skin. Erythema is more blood flow (flushed, i.e. embarrassed or hot). Pallor is less blood flow so paler skin (when cold). Cyanosis is a blueish tinge when the blood is lacking o2(due to being ‘trapped’ when cold). (think of Reynaud’s) jaundice is a yellow/green coloration when bilirubin (hemoglobin breakdown product from the liver) leaks into the blood stream. 5. Identify the cutaneous glands, their secretions, and the function of that secretion. Sudoriferous glands (sweat)- Eccrine glands - thermoregulating sweat. Apocrine glands - oily secretion with pheromones Sebaceous glands (sebum)(holocrine)- associated with hair follicles, secretes a sticky, antibacterial substance for infection protection and to prevent dehydration of hair shaft and skin. Ceruminous glands - modified apocrine sweat glands in the external ear canal to protect and lubricate the tympanic membrane. Secretion mixes with dead keratinocytes and creates a waxy cerumen. Mammary glands - modified apocrine glands that produce milk. Lacrimal glands - exocrine glands in the eyes that protect them. Ciliary glands - apocrine glands found next to the base of the eyelashes and keeps eyelashes from drying out. 6. Compare and contrast the structure and growth of hair and nails (include accessory structures). Hair structure: shaft, root and bulb. Growth : matrix cells continuously for 2-8 years - .33mm a day. They stop replicating for 1-3 months, then start growing a new hair that pushes out the old. Nail structure: tightly packed, hard, dead keratinized epidermal cells with an edge, plate/ body, and root. Anchored by the hyponychium. Growth: 1 mm a week from the nail matrix in the root. 7. Compare the basics of how skin heals following a surface (epidermal) injury – such as a shallow paper cut -- vs. a deep (dermal) injury – such as burning your hand on a stove. An epidermal wound only needs migration of the keratinocytes to fill in the stratum Basale. Basal cell break contact with the basement membrane and migrate until they meet advancing

from the opposite side of the wound. (contact inhibition). Deep wound requires fibroblasts to grow back some of the dermis before the epidermis can. The new dermis does not regenerate any of the usual accessory structures, only the blood vessels. Neuron regeneration is a hit or miss. Scar tissue is formed and may loose some function. Chapter 7 & 8 1. Describe the 5 types of bones (based on shape) and give at least 2 examples of bones that fall in each category (except for the one type with only one good example ). Long bone - humerus and phalanges Short bones - carpals and cuneiforms Flat bones - sternum, pariatial bone and most of the scapula Irregular bones - vertebrae, sphenoid and part of the scapula Sesamoid bones - patella 2. Explain the differences between each of the following groups of bone structure terms: a. Foramen vs. Meatus/Canal vs. Fissure Foramen - hole through a bone Meatus- a tubular tunnel/ passage through a bone Canal- tubular/passage through a bone Fissure - slit through the bone b. Process vs. Epicondyle vs. Trochanter vs. Tuberosity Process - any bony prominence. Epicondyle - and expanded region proximal to a condyle. Trochanter - 2 massive process only on the femur. Tuberosity - rough elevated process. c. Condyle vs. Head vs. Facet/Auricular surface Condyle - rounded knob that articulates with another bone Head - the prominent expanded end of bone, sometimes rounded. Facet - smooth, flat slightly concave/vex articular surface. Articular surface - an area of bone that articulates with another. 3. Describe the functions of bone. Structural support Protection of internal organs Assistance In movement Mineral/electrolyte homeostasis Hemopoiesis Triglyceride storage 4. Draw and label the structures related to long bones

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