front 1 Which layer of the skin--dermis or epidermis--is better nourished? | back 1 The dermis is connective tissue, which is vascular, so its cells would be better nourished than those of the epidermis, which is avascular epithelium. |
front 2 While walking barefoot in a barn, Jeremy stepped on a rusty nail that penetrated the epidermis on the sole of his foot. Name the layers the nail pierced from the superficial skin surface to the junction with the dermis. | back 2 Since the sole of the foot has thick skin, the layers from most superficial to deepest would be the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and startum basale. |
front 3 The stratum basale is also called the stratum germinativum, a name that refers to its major function. What is that function? | back 3 The stratum basale undergoes almost continuous mitosis to replace cells lost by abrasion. |
front 4 Why are the desmosomes connecting the keratinocytes so important? | back 4 The skin is subjected to a lot of abrasion and physical trauma. The desmosomes, which are connecting junctions, help to hold the cells together during such stress. |
front 5 Which layer of the dermis responsible for producing fingerprint patterns? | back 5 The papillary layer of the dermis gives rise to fingerprint patterns. |
front 6 Which tissue of the hypodermis makes it a good shock absorber? | back 6 Fatty tissue in the hypodermis gives it insulating and shock-absorbing properties. |
front 7 You have just gotten a paper cut. It is very painful, but it doesn't bleed. Has the cut penetrated into the dermis or just the epidermis? | back 7 Because there is no bleeding, the cut has penetrated into the avascular epidermis only. |
front 8 Melanin and carotene are two pigments that contribute to skin color. What is the third and where is it found? | back 8 The third pigment contributing to skin color is hemoglobin, the pigment contained in red blood cells found in blood vessels of the dermis. |
front 9 What is cyanosis and what does it indicate? | back 9 Cyanosis is a bluish cast of the skin that indicates that hemoglobin in the red blood cells in the dermal capillaries is poorly oxygenated. |
front 10 Which alteration in skin color may indicate a liver diorder? | back 10 Jaundice or a yellow cast to the skin due to the deposit of yellow bile pigments in body tissues may indicate a liver disorder |
front 11 What are the concentric regions of a hair shaft, from the outside in? | back 11 The regions of a hair from outside in are the cuticle, cortex, and medulla. |
front 12 Why is having your hair cut painless? | back 12 There are no nerves in a hair, so cutting hair is painless. |
front 13 What is the role of an arrector pili muscle? | back 13 The arrector pili muscles pull the hair (normally slanted) to the upright position (when cold or scared). |
front 14 What is the function of the hair papilla? | back 14 The hair papilla contains a knot of capillaries that supplies nutrients to cells of the hair bulb. |
front 15 Why is the lunule of a nail white instead of pink like the rest of the nail? | back 15 The lunule of the nail is white because the thick nail matrix that underlies it blocks the rosy color of the dermal blood supply from showing through. |
front 16 Why are nails so hard? | back 16 Nails are hard because the keratin they contain is the hard keratin variety. |
front 17 Which cutaneous glands are associated with hair follicles? | back 17 Sebaceous (oil) glands and apocrine glands are associated with the hair follicles. |
front 18 When Anthony returned home from a run in 85ºF weather, his face was dripping with sweat. Why? | back 18 His sympathetic nervous system activated his eccrine sweat glands and caused heat-induced sweating in order to cool the body. |
front 19 What is the difference between heat-induced sweating and a "cold-sweat", and which variety of sweat gland is involved? | back 19 Heat-induced sweating occurs all over the body when we are overheated. A cold sweat is emotionally induced sweating that begins on the palms, soles, and armpits and then spreads to other body areas. Both types of sweating are produced by the eccrine sweat glands, but activity of apocrine sweat glands is also likely during a cold sweat. |
front 20 Sebaceous glands are not found in thick skin. Why is their absence in those body regions desirable? | back 20 The palms of the hands and soles of the feet are thick skin areas. It would be dangerous to have oily sols, and oily palms would decrease the ability of hands to hang onto things. |
front 21 What chemicals produced in the skin help provide barriers to bacteria? | back 21 The low pH of skin secretions (acid mantle) inhibits division of bacteria, and many bacteria are killed by dermcidin in sweat, bactericidal substances in sebum, or natural antibiotics called defensins produced by skin cells. Damaged skin secretes cathelicidins that are effective against a certain strain of strep bacteria. |
front 22 Which epidermal cells play a role in body immunity? | back 22 The epidermal dendritic cells play a role in body immunity. |
front 23 How is sunlight important to bone health? | back 23 sunlight causes the skin to produce a precursor of vitamin D from cholesterol. Vitamin D is essential for absorption of calcium from the diet, and calcium is a major component of bone. |
front 24 When blood vessels in the dermis constrict or dilate to help maintain body temperature, which type of muscle tissue that you learned about (in Chapter 4) acts as the effector that causes blood vessel dilation or constriction? | back 24 The effector in this case is smooth muscle. |
front 25 Which type of skin cancer develops from the youngest epidermal cells? | back 25 Basal cell carcinoma develops from the youngest epidermal cells. |
front 26 What name is given to the rule for recognizing hte signs of melanoma? | back 26 The ABCD rule helps one to recognize signs of melanoma. |
front 27 The healing of burns and epidermal regeneration is usually uneventful unless the burn is a third-degree burn. What accounts for this difference? | back 27 First- and second-degree burns can heal uneventfully by regeneration of epidermal cells as long as infection does no occur. Third-degree burns destroy the entire depth of skin and regeneration is not possible. Infection and loss of body fluid and proteins make recovery problematic. |
front 28 Although the anterior head and face represent only a small percentage of the body surface, burns to this area are often more serious than those to the body trunk. Why? | back 28 Burns to the face are serious because damage to the respiratory passageway can occur in such burns. |
front 29 Which epidermal cell type is most numerous? | back 29 keratinocyte |
front 30 Which cell functions as part of the immune system? | back 30 dendritic cell |
front 31 The epidermis provides a physical barrier due largely to the presence of | back 31 keratin |
front 32 Skin color is determined by | back 32 the amount of blood, pigments, oxygenation level of the blood |
front 33 The sensations of touch and pressure are picked up by receptors located in | back 33 the dermis |
front 34 T or F The papillary later of the dermis is most responsible for the toughness of the skin | back 34 False |
front 35 Skin surface markings that reflect points of tight dermal attachment to underlying tissues are called | back 35 flexure lines |
front 36 T or F A sensory receptor is an epidermal derivative. | back 36 False |
front 37 An arrector pili muscle | back 37 can cause a hair to stand up straight |
front 38 The product of this type of sweat gland includes protein and lipid substances that become odoriferous as a result of bacterial action. | back 38 apocrine |
front 39 Sebum | back 39 lubricates the surface of the skin and hair, consists of cell fragments and fatty substances, and in excess may cause seborrhea |
front 40 Which layer of the skin has NO blood vessels? | back 40 epidermis |
front 41 T or F The hypodermis layer is NOT part of your skin. | back 41 True |
front 42 The skin makes up what percentage of body weight in the average adult? | back 42 7% |
front 43 T or F Keratin contributes to skin color. | back 43 False |
front 44 This layer of the skin is responsible for our fingerprints. | back 44 Papillary dermis |
front 45 Mitosis occurs in primarily in which stratum of the epidermis? | back 45 Basale |
front 46 What protein gives the epidermis its protective properties? | back 46 Keratin |
front 47 Which cells in the epidermis are key activators of the immune system? | back 47 Dendritic cells |
front 48 Dogs track the scent of epithelial cells that are constantly being shed. These cells shed from which stratum? | back 48 Corneum |
front 49 In which layer of the epidermis would you most expect to find the healthiest cells? | back 49 Basale |
front 50 The dermis is composed of what type of tissue? | back 50 Connective |
front 51 T or F Keratin is not associated with the dermis. | back 51 True |
front 52 Which layer of the dermis is composed of dense irregular connective tissue? | back 52 Reticular layer |
front 53 Which layer of the dermis is closest to the epidermis? | back 53 Papillary layer |
front 54 Peglike folds of the superficial layer of the dermis are called dermal | back 54 papillae |
front 55 Sudoriferous glands are also known as ____ glands | back 55 sweat |
front 56 What is sweat mostly composed of? | back 56 Water |
front 57 The sweat glands that are important in body temperature regulation are the ____ glands. | back 57 eccrine |
front 58 This gland, found in the skin, is also a holocrine gland. | back 58 Sebaceous |
front 59 T or F Ceruminous glands are not accessory glands of the skin | back 59 False |
front 60 Hair and nails are modifications of the | back 60 epidermis |
front 61 The protein found in our hair and nails is | back 61 keratin |
front 62 The smooth muscle associated with a hair follicle is called | back 62 arrector pili |
front 63 T or F The lunule is associated with hair. | back 63 False |
front 64 T or F The medulla is associated with the nails. | back 64 False |
front 65 When people gain weight, they often also gain inches due to an accumulation of fat in which layer? | back 65 Hypodermis |