anatomy chapter 5

Which of the following statements is INCORRECT? -Tactile cells anchor the skin to the underlying structures of the body. -Keratinocytes produce a fibrous protein that gives the epidermis its protective properties. -Dendritic cells ingest foreign substances and activate the immune system. -Melanin protects the nuclei of keratinocytes against ultraviolet (UV) radiation.

Tactile cells anchor the skin to the underlying structures of the body. -Tactile cells, in conjunction with their sensory nerve endings, function as touch receptors. The hypodermis, not tactile cells, anchors skin to the underlying structures (mostly to muscles), but loosely enough that the skin can slide relatively freely over those structures.

Which of the following explains why eyebrows do NOT grow as long as the hair on the head? -The hair follicles in the scalp are responsive to androgens, however the hair follicles of the eyebrows are not. -The hairs on the head have a cuticle, whereas the hairs of the eyebrows do not. -The hair follicles of the eyebrows are active for only a few months before becoming inactive; the hair follicles in the scalp are active for years before becoming inactive. -The hair follicles of the eyebrows exhibit a resting phase, but the hair follicles in the scalp do not. -The hair follicles in the scalp have a hair matrix, but the hair follicles of the eyebrows do not.

The hair follicles of the eyebrows are active for only a few months before becoming inactive; the hair follicles in the scalp are active for years before becoming inactive. -The life span of a hair varies. In the scalp, the follicles stay active for an average of four years, so individual hairs grow significantly long before being shed. In contrast, the follicles in eyebrows are active for only a few months, so the eyebrows never grow very long.

What is the role of the hair matrix? -The hair matrix produces hair. -The hair matrix serves as a sensory receptor. -The hair matrix serves as an anchor for the hair shaft. -The hair matrix allows hair to "stand on end," or become erect.

The hair matrix produces hair. -The hair matrix is the actively dividing area of the hair bulb that produces hair. As the matrix produces new hair cells, the older part of the hair is pushed upward, and its fused cells become increasingly keratinized and die.

How can the rule of nines help indicate whether a burn should be considered critical? -The rule of nines indicates that for every 9 square centimeters of skin surface that is burned, the severity of the burn increases. -The rule of nines states that for every nine specified locations of the body that are burned, the degree of burn severity increases. -The rule of nines can provide a rough estimation of the percentage of body surface affected by a burn. -The rule of nines helps to indicate the depth of the burn through the different layers of the skin.

The rule of nines can provide a rough estimation of the percentage of body surface affected by a burn. -The rule of nines divides the body into 11 regions of 9%%each, plus 1%% for the perineal area. For example, one whole arm, front and back, accounts for approximately 9%% of the body surface. Critical burns are classified by the degree or depth of the burn and the surface area affected.

Which of the following represents a difference between eccrine sweat glands and apocrine sweat glands? -Eccrine sweat glands use exocytosis to secrete their product, while apocrine sweat glands do not. -Eccrine sweat glands begin to function at puberty, while apocrine sweat glands function throughout life. -The secretions of apocrine sweat glands contain more fat and protein than do the secretions of eccrine sweat glands. -Eccrine sweat glands are located deeper in the dermis than apocrine sweat glands.

The secretions of apocrine sweat glands contain more fat and protein than do the secretions of eccrine sweat glands. -Compared to the watery secretions of eccrine glands, apocrine sweat glands produce a more viscous secretion that is enriched with fats and proteins.

You have learned that tape or adhesive bandages must be removed carefully from the skin on patients who are elderly to avoid tearing their fragile skin. What accounts for the fragility of their skin? -The stratum basale does not function in patients who are elderly. -The epidermal dendritic cells in the skin of patients who are elderly often become sensitized to adhesives and cause an immune reaction. -There are fewer collagen and elastic fibers in the reticular layer of the dermis as we age, contributing to wrinkling and increased susceptibility to tearing of the skin. -Dermal papillae are absent from the skin of patients who are elderly, so the epidermis is more easily separated from the dermis.

There are fewer collagen and elastic fibers in the reticular layer of the dermis as we age, contributing to wrinkling and increased susceptibility to tearing of the skin. -As we age, environmental damage, such as ultraviolet radiation, and decreased ability of our fibroblasts to renew collagen and elastic fibers make our skin thinner and more vulnerable to mechanical trauma.

Which of the following best describes a third-degree burn? -a burn that affects the entire thickness of the integument -a burn that affects at least 25% of the body surface area -a burn that presents extremely painful blisters, redness, and swelling -a burn that affects all of the layers of the epidermis

a burn that affects the entire thickness of the integument -Degree refers to the regions of skin affected by the burn. Third-degree burns are full-thickness burns that involve the entire thickness of the skin.

In a woman that has hirsutism, ________. -the keratin filaments in hair undergo cell division to thicken the hair -androgens stimulate vellus hair to become terminal hair -the cuticles in the visible portions of hair shafts undergo extensive cell division -hair will thin and grow slowly

androgens stimulate vellus hair to become terminal hair -Androgens are group of chemically-related male sex hormones that induce male-specific body changes. Normally they are produced in females at very low levels. But when their levels rise, they can cause changes like hair growth on the body and face.

A Caucasian patient with pale skin is treated for low blood pressure with medication that elevates the blood pressure; however, the skin's pallor does not change. Which of the following is the most likely cause of the pallor in this patient? -respiratory disease that results in the blood being poorly oxygenated -the presence of hematomas in the skin -hypertension caused by excessive use of the medication -Anemia

anemia -Red blood cells (RBCs) help give blood its color. Anemia is a set of signs and symptoms that appear when a person does not have enough healthy RBCs. Pallor, or paleness, is a sign/symptom of anemia because the blood vessels in the dermal layer lack normal RBCs

Which skin function is not correctly matched with the structure that accounts for that function? -keratinocytes: physical barrier -tactile corpuscles: cutaneous sensation -eccrine glands: excretion -apocrine gland: thermoregulation

apocrine gland: thermoregulation -While the function of the apocrine cells is not well understood, they do not provide much assistance in thermoregulation because of their location.

Which of the following would be a sign of a melanoma? -uniform coloration -regular borders -a size smaller than 6 mm -asymmetry

asymmetry -Cancerous growths exhibit asymmetry. Benign growths exhibit symmetry, regular borders, uniform coloration, and they are usually less than 6 mm in diameter.

Which of the following is NOT an immediate threat to the body as a result of a severe burn? -renal failure -bacterial infection -electrolyte imbalance -dehydration

bacterial infection -While it is true that infection is a long-term threat, it is not the most immediate threat to homeostasis. The immediate threat to life resulting from severe burns is a catastrophic loss of body fluids containing proteins and electrolytes. This leads to dehydration and electrolyte imbalance, and then renal failure (kidney shutdown) and circulatory shock (inadequate blood circulation due to reduced blood volume). To save the patient, the lost fluids must be replaced immediately by administration of intravenous (IV) fluids.

Which of the following would not be a correct characteristic of melanoma? -diameter of 12 mm -color that is dark black or brown -border regularity -asymmetry

border regularity -Border irregularity would be a sign of melanoma, especially if you were to see rough or notched edges.

The skin is permeable to organic solvents, such as acetone or paint thinner, because they ________. -can dissolve the lipid bilayers of epidermal and dermal cell plasma membranes -are small molecules that bypass skin cells and therefore directly enter the blood -solubilize the skin's keratin filaments -solubilize the skin's collagen fibers

can dissolve the lipid bilayers of epidermal and dermal cell plasma membranes -Organic solvents are carbon-based substances that are capable of dissolving or dispersing one or more other substances like the phospholipids of the plasma membrane.

Skin cancer arising in the stratum basale is called basal cell ____

carcinoma

Which muscle cell type has visible striations but is not under voluntary control? -cardiac -smooth -skeletal

cardiac -Yes, cardiac cells, like skeletal cells, have visible striations but are not under voluntary control.

Which part of the neuron (a specialized nerve cell) receives signals from other cells and is also the main metabolic region of the neuron? -axon -cell body -dendrites

cell body -Yes, the cell body or soma receives inputs (signals) from other cells and sends the information to the axon. But unlike a dendrite, it also is the main metabolic and nutritional center of the cell.

Earwax is made by __________. mammary glands ceruminous glands eccrine glands

ceruminous glands -Ceruminous glands are modified apocrine sweat glands found in the lining of the external ear canal. Their secretion mixes with sebum produced by nearby sebaceous glands to form a sticky, bitter substance called cerumen, or earwax, which is thought to deter insects and block entry of foreign material.

The prefix ____ means cartilage.

chondr

The mature cells that live in cartilage and maintain the matrix around them are ____

chondrocytes

The word root ____ means skin.

derm

The deep layer of skin is called the ____

dermis

You are asked to classify an exocrine gland found in the skin based solely on the chemical analysis of its product, which turns out to be a hypotonic fluid consisting of about 99% water with a pH of 5. It contains NaCl, traces of urea and ammonia, and a peptide called dermcidin, but lacks fats and proteins. How would you classify this gland? -ceruminous gland -sebaceous gland -eccrine gland -mammary gland

eccrine gland -Eccrine gland secretion, commonly called sweat, is a hypotonic filtrate of the blood that passes through the secretory cells of the sweat glands and is released by exocytosis. It is 99% water, with some salts (mostly sodium chloride), traces of metabolic wastes (urea, uric acid, and ammonia), and a microbe-killing peptide called dermcidin. Normally, sweat is acidic with a pH between 4 and 6.

true or false: Vitamin D precursors are produced in the skin in the presence of sunlight. These chemicals are important for the transport of sodium in our intestines.

false -It is true that vitamin D precursors are produced in the skin as modified cholesterol is converted into cholecalciferol when the skin is exposed to UV light. However, vitamin D plays various roles in calcium, not sodium, metabolism. For example, calcium cannot be absorbed from the digestive tract without vitamin D.

true or false: Sweating and shivering are two ways in which the skin contributes to regulation of body temperature.

false -Sweating and redistribution of blood flow are two ways in which the skin contributes to thermoregulation. Sweat glands secrete water (sweat) onto the surface of skin, which removes body heat as it evaporates. By dilating cutaneous blood vessels, blood flow to the skin is increased, which increases heat loss to the surrounding environment. By constricting cutaneous blood vessels, blood flow to the skin is decreased, which reduces heat loss from the body. Shivering is an action carried out by the skeletal muscles, not the skin, to generate body heat when we are cold.

true or false: The biggest risk factor for the development of skin cancer is excessive exposure to ultraviolet radiation from sunlight. Exposure to the type of UV light emitted from a tanning bed is far less dangerous.

false -The single most important risk factor for skin cancer is overexposure to the UV radiation in sunlight and tanning beds. 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." Tanning beds use the same types of UV radiation found in natural sunlight, often at even higher intensities, to stimulate melanin production.

true or false : New portions of a nail are produced at the cuticle.

false - The nail matrix is the thickened proximal portion of the nail bed responsible for nail growth. The cuticle is the part of the proximal skin fold, or nail fold, that projects onto the nail body.

The prefix ____ means fiber or fibrous.

fibro

____ is a type of cartilage with a net of collagen fibers to help resist compression and tension.

fibrocartilage

Which of the following is a layer of the epidermis found in thin skin? -papillary layer -reticular layer -clear layer -granular layer

granular layer

In alopecia, new hair growth stops because cell division is inhibited in the_________. -epithelial root sheath -cuticle -hair matrix -hair follicle receptor

hair matrix -Cell division in the hair matrix produces the cells that will form the hair fiber and the inner root sheath. The hair matrix epithelium is one of the fastest growing cell populations in the human body.

Respiratory failure can lead to a change in the color of the skin, which is more evident in light-skinned individuals. Which pigmentation factor is affecting this change? hemoglobin folic acid carotene melanin

hemoglobin -When hemoglobin is poorly oxygenated, the skin may take on a bluish-gray tint, especially in the mucous membranes and nail beds. Cyanosis, or blueness, can be a sign of respiratory or cardiovascular problems.

Surface skin cells regenerate from stem cells found in which specific region? -in the deepest layer of the skin -in the papillary layer of the dermis -in the stratum basale -in the stratum corneum

in the stratum basale -The stratum basale is the deepest layer of the epidermis, and the location of highly mitotic cells.

What is the most common cell type in the epidermis? fibroblasts keratinocytes dendritic cells macrophages

keratinocytes

Serious burns pose a significant threat to the body because they can __________. -lead to kidney failure and circulatory shock -lead to nervous system failure and permanent paralysis -lead to liver failure, which, if untreated, can lead to blood toxicity -lead to destruction of muscle tissue, resulting in permanent loss of mobility

lead to kidney failure and circulatory shock -Burns can destroy the layers of skin that retain fluids in the body. When burns cause a drastic loss of these fluids, including electrolytes and proteins, kidney and circulatory failure can occur.

The word root _____ means breast.

mamm

Milk-producing glands in the breast are _____

mammary glands

The word root ____ means black or dark.

melan

Which skin pigment is made in the skin as a natural defense against UV radiation? carotene hemoglobin keratin melanin

melanin

The cells that produce melanin are _____

melanocytes

The most dangerous type of skin cancer is __________. -squamous cell carcinoma -melanoma -basal cell carcinoma -All of these skin cancers are equally dangerous.

melanoma -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.

The prefix ___ means middle or intermediate.

mes

The middle portion of unspecialized mesoderm from which cartilage, bone, and blood develop is called _____

mesenchyme

The skin is not a __________ barrier. -physical -metabolic -chemical -biological

metabolic -The skin constitutes at least three types of barriers, but it is not a metabolic barrier.

The integument's ability to resist tearing when stretched is largely due to the __________. -abundance of dense fibers found in the papillary layer of the dermis -network of collagen fibers present in the reticular layer of the dermis -desmosomes that bind together the cells of the stratum basale -dead, flattened layers of keratinized cells that fuse to form the stratum corneum

network of collagen fibers present in the reticular layer of the dermis -The dermis is thick and strong, made up of dense fibrous connective tissue.

The word root ____ means tumor.

oma

Which type of cell or cellular structure is not found in the epidermis? dendritic cells melanocytes pain receptors keratinocytes

pain receptors -Pain receptors formed by free nerve endings are found deep to the epidermis in the papillary layer of the dermis.

Critical burn injuries will likely be treated with all of the following EXCEPT __________. -significant infection control measures -pressing an ice-cold washcloth, towel, or pad to the burned area -an intravenous supply of fluids -providing the patient with thousands of extra nutritional calories

pressing an ice-cold washcloth, towel, or pad to the burned area -Pressing a cold pad to a mildly burned site, such as a sunburn, may relieve some discomfort. For a critical burn, however, this is not as important as treating other factors.

Which of the following is NOT a function of sebum? protection from UV radiation prevention of water loss lubrication of the skin protection from bacteria

protection from UV radiation -This is false; it is melanin (not sebum) that protects the skin from the damaging effects of UV radiation. Sebum serves as a lubricant, an antibacterial agent, and protects against water loss.

The prefix ___ means made like a net or web.

ret

____ is the type of connective tissue that forms a structural net to support other cells.

reticular connective tissue

In general, skin cancer is least likely to develop in which of the following locations? scalp forehead nose the back of the hand

scalp

Which glands secrete an oily product that softens the skin and hair? -sebaceous glands -apocrine sweat glands -ceruminous glands -eccrine sweat glands

sebaceous glands -Sebaceous glands secrete an oily substance called sebum. Sebum softens and lubricates the hair and skin, slows water loss from the skin when external humidity is low, and has bactericidal properties.

Overactive sebaceous glands can cause... -fine hairs on the forehead to become brittle. -the forehead's skin to become dry. -bacteria on the forehead's skin to grow and multiply freely. -seborrhea, a disease characterized by red, itchy lesions on the scalp

seborrhea, a disease characterized by red, itchy lesions on the scalp. -Excessive sebum production by overactive sebaceous glands can be irritating to the skin. This can cause oily, scaly patches, which can cause oily scales to flake off of the skin.

Susan sat out in the sun watching a baseball game. She developed small blisters on her unprotected shoulders and neck. What type of burn is represented by the formation of the blisters? -first-degree burn -second-degree burn -third-degree burn -full-thickness burn

second-degree burn -Second-degree burns injure the epidermis and the superficial region of the dermis. Symptoms mimic those of first-degree burns, but blisters also appear.

The proximal tubule of the nephron (kidney tubule) in the kidney is composed of which type of epithelium? -simple cuboidal epithelium -ciliated pseudostratified columnar epithelium -stratified squamous epithelium

simple cuboidal epithelium -Yes, the simple cuboidal cells line the kidney tubules (nephrons) so that secretion and absorption can take place.

The wall of the alveolus (air sac) in the lung is composed of which type of epithelium? -transitional epithelium -simple columnar epithelium -simple squamous epithelium

simple squamous epithelium -Yes, this single layer of squamous cells is ideal for the diffusion of gases in the lungs.

Which of the three muscle cell types has multiple nuclei? -smooth -cardiac -skeletal

skeletal -Yes, skeletal muscle cells are elongated and many can be quite long; therefore, they have multiple nuclei.

The prefix ____ means layers.

strat

Any tissues that exist in layers and form linings or coverings fall into the category of ____

stratified epithelia

The epithelium of the esophagus is composed of which type of epithelial tissue? -simple columnar epithelium -stratified squamous epithelium -keratinized stratified squamous epithelium

stratified squamous epithelium -Yes, this epithelium protects underlying tissues from the wear and tear of constant swallowing in the esophagus.

Pigment can be found in several layers of the epidermis. In which layer would you expect to find the cells that produce melanin? -stratum basale -stratum granulosum -stratum lucidum -stratum spinosum

stratum basale

Which stratum of the epidermis contains the stem cells responsible for regenerating the more superficial layers? -stratum spinosum -stratum granulosum -stratum corneum -stratum basale

stratum basale

Which of the following layers is found only on the palms of the hands or the soles of the feet? -stratum granulosum -stratum corneum -stratum lucidum -stratum basale

stratum lucidum -Stratum lucidum is found only in the thick skin on the soles of the feet or palms of the hands. When present, it is located between the stratum corneum and stratum granulosum.

The word root ____ means under, below, or beneath.

sub

An injection given under the skin is a _____ injection.

subcutaneous

Which of the following is a metabolic function of skin? -cutaneous sensation -synthesis of a vitamin D precursor -elimination of nitrogenous wastes -body temperature regulation

synthesis of a vitamin D precursor -Yes, this is a function of the skin carried out by chemical reactions in the skin. When sunlight bombards the skin, modified cholesterol molecules are converted to a vitamin D precursor, which is transported via the blood to the liver and kidneys, where it is converted into active vitamin D.

Which epidermal cells act as sensory touch receptors? -keratinocytes -dendritic cells -melanocytes -tactile cells

tactile cells -tactile means "touch." Tactile cells along the border between the epidermis and dermis are touch receptors.

The source of the fluid that accumulates in a blister is ________. -water that is absorbed from the environment into the skin -water that is squeezed out of the overlying epidermal cells -the plasma of the blood flowing through the numerous dermal blood vessels -none of the above

the plasma of the blood flowing through the numerous dermal blood vessels

Which dermal layer is responsible for the dermal properties of skin that are evident as cleavage lines? the reticular layer the basal layer the granular layer the papillary layer

the reticular layer

Which of the following does NOT protect the skin from bacteria? -the low pH of the skin -the temperature of the skin -cathelicidins -defensins -dermcidin

the temperature of the skin -The temperature of the skin does not protect the skin against bacteria. In fact, the temperature of the skin is ideal for many types of bacteria.

If a person were born without eccrine glands, what skin function would he or she have a hard time completing? -cutaneous sensation -synthesis of vitamin D -having the skin act as a physical barrierthermoregulation

thermoregulation -Sweat is used for thermoregulation. As sweat is released onto the surface of the epidermis, heat from the body is conducted into the water. Water is a better conductor of heat than air is. As the sweat evaporates, the heat from the body dissipates into the environment.