hw ch 5
Which statements describe the function and structure of the skin? 1. Collagen is the strongest fiber in the skin; 2. Blood vessels in the dermis supply the epidermis with nutrients; 3. The arrangement of epidermal ridges, mixed with sweat create fingerprints; 4. The papillary layer is the strongest portion of the dermis; 5. The reticular layer promotes stretching of the skin.
1, 2, 4, 5
Which statements describe sebaceous glands? 1. oil producing 2. merocrine 3. holocrine 4. thermoregulation 5. sebum 6. apocrine
1, 3, 5
Choose the following statements that describe keratin. 1. Keratin is a tough, fibrous protein; 2. Keratin is used for pigmenting skin; 3. Keratin helps protect the skin; 4. Keratin participates in immune responses; 5. Keratin protects the skin from UV light.
1,3
A pair of scissors slips while you are cutting paper. You slice through your forearm and blood appears. What is the order of the skin you cut from superficial to deep. 1. Dermis; 2. Stratum spinosum; 3. Stratum granulosum; 4. Stratum corneum; 5. Stratum basale; 6. Stratum lucidum.
4, 3, 2, 5, 1
Which is the most abundant cell in the epidermis?
A
In the figure of a sagittal section of a fingernail shown, a hangnail is associated with drying of what area?
B
Which of the following statements about a hair are true?
Consists of a shaft, root and a hair follicle The arrector pili muscle is responsible for "goose bumps". The root of a hair penetrates the dermis All of these statements are true.
In the figure of a sagittal section of a fingernail shown, the area that lacks the stratum granulosum is primarily protected by
D
In the figure of a sagittal section of a fingernail shown, which area is comparable to the stratum corneum with visible vascular tissue beneath?
D
Which structure in the figure produces a pigment that contributes to skin color and absorbs UV radiation?
D
In the diagram, which area is composed of areolar connective tissue?
E
In the diagram, which is the papilla of the hair?
E
In the figure of a sagittal section of a fingernail shown below, which area acts similar to stratum basale, with mitotic cells?
E
Which of the below structures responds by sweating when the body is overheated (thermoregulation)?
E
Which structures house Meissner's corpuscles, free nerve endings and capillary loops?
I
In a skin infection, which cell will take up and process microbial antigens?
Intraepidermal macrophages (Langerhans cells)
Which of the following is the most direct way that the skin contributes to the function of the muscular system?
It helps provide calcium ions needed for contraction.
About 90% of the cells of the epidermis are of which type?
Keratinocytes
Which pigment secreted by specialized cells in the skin is capable of absorbing ultraviolet light?
Melanin
Which of the following statements is correct?
Melanin, carotene and hemoglobin impart color to the skin. The amount of melanin causes skin's color to vary from pale yellow to black. The differences in skin color are due to the amount of melanin produced and moved to the keratinocytes. All of these statements are correct.
Which exocrine gland is primarily used for thermoregulation?
Eccrine sweat gland
From which of the primary germ layers of the embryo does the epidermis of the skin develop?
Ectoderm
Which of the following best describes the events occurring at point B in the diagram of deep wound healing shown below?
Epithelium is migrating across wound.
In the diagram of a hair root shown, which area is composed of dense connective tissue?
F
In the diagram, where are actively dividing cells located?
G
In the diagram, where does apoptosis occur?
G
Which structure is primarily responsible for thermoregulation?
G
The skin provides a physical and chemical barrier to harmful agents by:
Production of antibacterial substances The maintenance of an acidic pH Presence of macrophages All of these
Vitamin C is important for collagen synthesis. Which area of the skin would be most affected if there is a deficiency in vitamin c?
Reticular region of the dermis
The skin perceives a variety of sensations from several types of sensory receptors. Which receptor would let a person know if there was a small insect walking across a hair on their arm?
Root hair plexus
This type of exocrine gland undergoes a higher rate of mitosis due to its holocrine secretion.
Sebaceous gland
Secretion mixture of fats, sterols, proteins and salts, that prevent water loss and can inhibit the growth of some bacteria.
Sebum
This layer is attached to the basement membrane by hemidesmosomes and to other cells by desmosomes.
Stratum basale
Which structure found in the skin plays an important role in thermoregulation?
Sweat glands
Which feature(s) of the skin protect(s) us against microbes such as bacteria?
The many layers of keratinized cells form a barrier against microbes Sebum contains compounds which kill bacteria Sweat has an acidic pH which suppresses microbial growth Langerhans cells can alert the immune system should microbes invade All of these are correct
Most adipose tissue in the body is considered 'white fat'. Why is the subcutaneous layer often yellowish-orange?
The pigment carotene is stored there.
Which is not true about melanocytes?
They undergo rapid mitosis to regenerate skin
Which statement best describes why the diagram represents thick skin? Choose the best answer.
Thick skin contains five stratums.
Which of the following areas in the diagram below gives the wound temporary integrity from external factors, like microbes?
a
Which structure in the figure produces a protein that helps protect the skin and underlying tissues from heat, microbes and chemicals?
a
Which structures in the figure are sensitive to warmth, coolness and itching?
a
Which structures develop as down growths of the stratum basale?
a) Sudoriferous glands c) Hair follicles d) a and c only
The majority of body hair of _________ is vellus rather than terminal hair.
adult females
Which of the following substances can penetrate the skin?
b) Fat soluble substances c) Oxygen and carbon dioxide d) Organic solvents like acetone e) b, c and d only
Which of the following functions of the skin explains the skin's pink hue?
blood reservoir
Which of the labeled cells in the diagram of deep wound healing shown below create the framework of fibers that new tissue is built?
c
Which structure in the figure detects touch sensations?
c
Which structure would recognize pulling of the skin during stitches even after a doctor anesthetizes the area?
f
Which of the following would not be a change to the skin that occurs with aging?
formation of lanugo
A raised scar that extends into previously normal tissue is a(n)
keloid scar
Sutures are required to close up a tear in the skin. What term best describes this injury?
laceration
Anorexia may cause adults to develop fine, unpigmented hairs to help with warmth and insulation. Which type of hair is described?
lanugo
Apoptosis of cells occurs within the
stratum granulosum
Which condition results from androgens inhibiting hair growth in genetically predisposed adults?
male-pattern baldness
Albinism is the inherited inability to produce
melanin
Without enzymatic action of tyrosinase, what pathway is blocked in the body pertaining to skin?
melanin production
The hyponychium is the __________ of the nail.
nail bed
What criteria are used to distinguish thick and thin skin?
Distribution on body Thickness and number of layers of epidermis Number and types of glands present. Presence of epidermal ridges All of these are criteria used.
As newly formed cells of the stratum basale are pushed to the surface, they accumulate keratin and undergo apoptosis. This process is referred to as _______.
Keratinization
Which is the correct sequence of phases for deep wound healing?
inflammation, migration, proliferation, maturation
Keratinized stratified squamous epithelium composes the
epidermis
Which layer has stem cells that undergo cell division to continually produce new keratinocytes?
stratum basale
Tactile epithelial cells are located in the
stratum basale.
This skin layer is only present in places subjected to high levels of mechanical wear-and-tear, and provide an additional protective layer where it occurs, such as in the soles of the feet, palms, and fingertips.
stratum lucidum
In the elderly, blood supply to the dermis is reduced and sweat glands are less active. This combination of factors would most affect
the ability to thermoregulate
The subcutaneous layer is also known as the
hypodermis
Which statements are true? 1. The majority of the skin does not contain stratum lucidum; 2. Stratum lucidum is found in areas of high friction, such as the palms and soles; 3. Live keratinocytes are located in the stratum lucidum; 4. Friction will cause the stratum lucidum to form calluses.
1 and 2
Which statements describing vitamin D are true. 1. The skin produces Vitamin D when exposed to UV light. 2. When the skin is exposed to UV light, it begins the reaction to convert the precursor molecule to calcitriol in the liver than kidneys. 3. Vitamin D supplements can be taken if individuals are not exposed to UV light. 4. Vitamin D stimulates the uptake of calcium from the intestines. 5. Vitamin D inhibits the function of phagocytes in immunity.
2, 3, 4
In the diagram of a hair root shown, which area may be missing in thinner hair?
A
Which of the following statements is incorrect?
Ceruminous glands produce a waxy substance which protects the genitals.
What factors contribute to the susceptibility of aging skin to infection?
Decrease in Langerhan's cell number Decrease in macrophage number Decrease in size of sebaceous glands resulting in dry broken skin. All of these contribute
The buildup of bilirubin in an infant's blood can occur if the liver does not remove the chemical. This condition is
JAUNDICE
Which of these statements is incorrect?
Tattoos may interfere with childbirth.
"Goose bumps" are caused by
contraction of arrector pili muscles.
A ballet dancer may form hardened areas over their toe joints due to constant pressure and friction from their point shoes. What skin condition most likely developed on their toe joints?
corn
You stepped on a nail. List the sequential strata of the epidermis that the nail penetrated through to reach the dermis.
corneum, lucidum, granulosum, spinosum, basale
The skin is known as the _________ membrane.
cutaneous
The skin is also known as a (the) _________.
cutaneous membrane
Put the events of keratinization in order. A. Accumulate keratohyalin granules; B. Cells increase in size, some retain ability to divide; C. Cell membrane thickens. Cells imbedded in lipid matrix; D. Cells within this layer proliferate
d,b,a,c
Dense irregular connective tissue will be found in the
dermis.
How do nutrients reach the epidermis?
diffusing through the tissue fluid from blood vessels in the dermis.
Which area stores approximately half of the body's lipid, secures the skin to underlying structures and consists of adipose and areolar connective tissue?
e
A child is examined for chronic, pruritic (itching), plaques that appear red in the flexural areas of the body. What condition is the child most likely presenting?
eczema
Which statement is not correct about the dermis?
it is thinner in men than in women
The pigment-producing cells of the epidermis are located in which layer?
stratum basale
An individual allergic to peanut butter eats a snack containing trace amounts. While the reaction is not severe, the individual shows signs of elevated patches all over their skin. These patches are
urticaria
During development in the womb, the fetus by the fifth month is covered and protected by a fatty substance called __________ .
vernix caseosa
