Chapter 5, 15 skin and special senses – Flashcards
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Which labeled structure produces an oily secretion?
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Sebaceous produces sebum, an oily secretion.
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Which of the following correctly describes a common feature of all structures labeled A-D in the figure?
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Each of the labeled structures is located within the dermal layer of the skin.
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Most of the cells in layers A through D are of which type?
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Keratinocytes are those cells that form the stratified layers of the epidermis.
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Which of the following would most likely be found in the stratum spinosum?
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Dentritic (Langerhan's) cells are phagocytic cells that migrate into the epidermis and are most abundant within the stratum spinosum (layer C in the figure).
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Which skin-color-associated, pigment-producing cell is located in the labeled layer D?
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Melanocytes within the stratum basale produce the pigment melanin, which is deposited within the deeper layers of the epidermis.
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The structure indicated by label E is part of which of the following?
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Dermal papillae are projections of the dermis that form indentations in the overlying epidermis.
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Which structure is a type of sudoriferous gland?
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Structure C is an eccrine gland, the most abundant type of sudoriferous (sweat) gland.
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Which structure is a type of cutaneous sensory receptor?
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Structure B is a pacinian corpuscle, one of several structural and functional types of cutaneous sensory receptors.
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The hypodermis is distinguished by an abundance of ______.
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fat cells
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The biggest risk factor for the development of skin cancer is excessive exposure to ultraviolet radiation from sunlight.
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True. The single most important risk factor for skin cancer is overexposure to the UV radiation in sunlight. UV radiation damages DNA bases and appears to disable tumor suppressor genes, leading to the formation of cancerous cells. There is no such thing as a "healthy tan."
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Choose the correctly paired terms. hyperopia: nearsightedness nyctalopia: night blindness astigmatism: clouding of the lens myopia: farsightedness
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nyctalopia: night blindness Night blindness, or nyctalopia, is a condition in which rod function is seriously hampered, impairing one's ability to drive safely at night
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What structure regulates the amount of light passing to the visual receptors of the eye?
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iris
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What is the most important role of the arrector pili muscles in humans?
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Force sebum out of the hair follicle to the skin surface
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Which of the following cells and their functions are correctly matched? Which of the following cells and their functions are correctly matched? A) Keratinocytes provide sense of touch and pressure B) Melanocytes protects cells in the stratum corneum from damaging effects of sun's rays C) Dendritic cells activate the immune system Tactile cells provide protection
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C) Dendritic cells activate the immune system
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Which layer is composed primarily of stratified squamous epithelium?
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The superficial layer of the skin is composed of keratinized stratified squamous epithelium.
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The design of a person's epidermal ridges is determined by the manner in which the papillae rest upon the dermal ridges to produce the specific pattern known as handprints, footprints, and fingerprints. Which of the following statements is true regarding these prints or ridges? A) Because we are constantly shedding epithelial cells, these ridges are changing daily. B) The dermal ridges are determined by human blood groups. C) They are genetically determined, therefore unique to each person. D) Every human being has the same pattern of ridges.
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C) They are genetically determined, therefore unique to each person.
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Which layer(s) of the skin is(are) damaged in a second-degree burn?
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Second-degree burns result in damage to the epidermis and the superficial region of the dermis.
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The reason the hypodermis acts as a shock absorber is that ________.
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the major part of its makeup is adipose, which serves as an effective shock absorber
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Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________.
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accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer
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Acne is a disorder associated with ________.
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sebaceous glands
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The dermis is rich in blood vessels and nerve fibers.
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True
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Tinnitus, vertigo, and gradual hearing loss typify the disorder called ________.
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Ménière's syndrome
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Which of the following is true about light and vision?
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When we see the color of an object, all light is being absorbed by that object except for the color being experienced.
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Visible light fits between ________.
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UV and infrared
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The only special sense not fully functional at birth is the sense of ________.
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Vision
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Changes in the color of skin are often an indication of a homeostatic imbalance. Which of the following changes would suggest that a patient is suffering from Addison's disease?
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The skin takes on a bronze or metallic appearance.
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The dermis has two major layers. Which layer constitutes 80% of the dermis and is responsible for the tension lines in the skin?
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the reticular layer
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A needle would pierce the epidermal layers of the forearm in which order?
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corneum, granulosum, spinosum, basale
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A physician is often able to detect homeostatic imbalances in the body by observing changes in the skin color.
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True
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Ordinarily, it is not possible to transplant tissues from one person to another, yet corneas can be transplanted without tissue rejection. This is because the cornea ________.
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has no blood supply
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The eye muscle that elevates and turns the eye laterally is the ________.
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inferior oblique
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The ________ is a thin translucent band found only in thick skin.
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The stratum lucidum, or clear layer, visible only in thick skin, is a thin, translucent band found just above the stratum granulosum.
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Melanin protects skin cell DNA from the damaging effects of ultraviolet (UV) radiation.
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True
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Vision is fully developed at birth.
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False
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The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis?
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fibroblasts, macrophages, and mast cells
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Which of the following is a skin sensory receptor for touch?
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Meissner's corpuscle
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Which region of the ear is involved in detection of both hearing and equilibrium? Select from choices A-D.
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Internal Ear
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Which of the following is a characteristic of the lens?
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The lens focuses light on the retina. The lens is a biconvex, transparent, flexible structure that can change shape to precisely focus light on the retina. It is enclosed in a thin, elastic capsule and held in place just posterior to the iris by the ciliary zonule. Like the cornea, the lens is avascular; blood vessels interfere with transparency.
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The protein found in large amounts in the outermost layer of epidermal cells is collagen.
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False; Keratin
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Regardless of race, all human beings have about the same number of melanocytes.
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True
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The most dangerous type of skin cancer is ________.
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Melanoma, cancer of melanocytes, is the most dangerous skin cancer because it is highly metastatic and resistant to chemotherapy. These cancers appear spontaneously, and about one-third develop from preexisting moles.
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The blind spot of the eye is where ________.
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The optic nerve leaves the eye
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Which of the following statements indicates the way in which the body's natural defenses protect the skin from the effects of UV damage?
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Prolonged exposure to the sun induces melanin dispersion, which in turn acts as a natural sunscreen.
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A cancerous growth on the skin will likely exhibit ________.
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asymmetry Cancerous growths exhibit asymmetry. Benign growths exhibit symmetry, regular borders, uniform coloration, and they are usually less than 6 mm in diameter.
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Even though we have two eyes, why do we normally see only one image?
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Information from each eye goes to both hemispheres for processing. Notice that both eyes are set anteriorly and look in approximately the same direction. Their visual fields, each about 170 degrees, overlap to a considerable extent, and each eye sees a slightly different view. The visual cortex fuses the slightly different images delivered by the two eyes, providing us with a single image and depth perception (or three-dimensional vision), an accurate means of locating objects in space.
