Anatomy and Physiology Chapter 5

This structure located in the epidermis serves as a tactile (touch) receptor. >lamellar corpuscle >root hair plexus >Merkel cell >Langerhans cell

>Merkel cell

What feature of the prickle cells in layer C causes them to have pointy projections after tissue preparation? (Refer to image #1) >pulling by shrunken keratin fibers between the cells >glycolipids that make the layer waterproof >their desmosome attachments >the rigidity of the cell membrane

>their desmosome attachments. Cells typically shrink during tissue preparation, and since these cells are attached by desmosomes, the membranes are pulled slightly outward. The location referred to is the stratum spinosum.

Which of these epidermal layers would be LEAST likely to develop cancer? (Refer to image #1) >A >C >D >E

>A. Cell of this layer are dead and do not participate in mitosis.

Which of these glands is properly matched with its mode of secretion? (Refer to image #3) >A; holocrine >A; merocrine >C; apocrine >C; holocrine

>A; holocrine. The gland at A secretes an oily material rich in lipids but does not do it through the use of vesicles and exocytosis.

__________ glands are found primarily in the genital and axillary areas. >Apocrine >Eccrine

>Apocrine.

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

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

Which layer is composed primarily of dense irregular connective tissue? ( Refer to image #2) >A >B >C >D

>C. Layer C consists primarily of dense, interwoven fibers of collagen designed to resist tearing from any direction.

Which structure is a type of sweat gland? >A >B >C >D

>C. Structure C is an eccrine gland, the most abundant type of sweat (sudoriferous) gland.

Earwax is made by __________. >sebaceous glands >apocrine 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.

Cell division would be most common among cells in which of the labeled layers? (Refer to image #1) >A >B >C >D

>D. Cells migrate upwards through the epidermis after being generated by mitosis in the stratum basale.

What is true about the blood supply to the skin? >Both epidermis and dermis are poorly vascularized. >Epidermis is richly vascularized and dermis is avascular. >Epidermis is avascular and dermis is richly vascularized. >Both epidermis and dermis are richly vascularized.

>Epidermis is avascular and dermis is richly vascularized.

Our skin helps us to regulate our body temperature by causing shivering. Is this statement true or false? >True >False

>False. 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. By constricting blood vessels in the skin, the body decreases blood flow to the skin and thereby lowers heat loss. Shivering is a muscular response that increases our body temperature when we are cold.

The biggest risk factor for the development of skin cancer is excessive exposure to ultraviolet radiation from sunlight. Exposure to UV light in a tanning booth is safer. Is this statement true or false? >True >False

>False. 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." Tanning booths use the same UV mechanism to stimulate melanin production; the UV exposure is the primary mechanism that leads to skin cancer.

Which glands secrete an oily product that softens the skin and hair? >apocrine sweat glands >sebaceous 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.

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.

Layers of epidermis & dermis Top to bottom

>Stratum Corneum >Stratum granulosum >Stratum spinosum >Stratum basale

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

>Stratum basale. Between 10 and 25% of the cells in the stratum basale are melanocytes that produce the melanin.

Which of the following correctly describes a common feature of all structures labeled A through D in the figure? >Structures A, B, C, and D are composed primarily of smooth muscle. >Structures A, B, C, and D are located in the dermis. >Structures A, B, C, and D are all various types of glands. >All the listed statements correctly describe structures A, B, C, and D.

>Structures A, B, C, and D are located in the dermis. Each of the labeled structures is located within the dermal layer of the skin.

Which of the following statements is INCORRECT? >Melanin provides protection against ultraviolet (UV) radiation. >Langerhans cells activate the immune system. >Keratinocytes produce a fibrous protein to protect the epidermis. >Tactile cells anchor the skin to the body.

>Tactile cells anchor the skin to the body. This is the incorrect statement. Tactile cells, in conjunction with their sensory nerve endings, function as touch receptors. The hypodermis, not tactile cells, anchors skin to the body.

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

>The hair follicle serves as an anchor for the hair shaft.

Which of the following represents a difference between eccrine sweat glands and apocrine sweat glands? >Eccrine sweat glands begin to function at puberty, while apocrine sweat glands function throughout life. >Eccrine sweat glands use exocytosis to make secretions, while apocrine sweat glands do not. >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 have secretions that are enriched with fats and proteins.

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

>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.

Layer B is composed primarily of __________. >areolar connective tissue >dense irregular connective tissue >dense regular connective tissue >simple squamous epithelium

>areolar connective tissue. The loose connective tissue within the papillary layer of the dermis is rich in blood vessels and cells that function in the body's defenses.

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

>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 would be a sign of a melanoma? >asymmetry >uniform coloration >a size smaller than 6 mm >regular borders

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

The skin is permeable to organic solvents, such as acetone or turpentine, 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.

What is the function of structure B? (Refer to image #3) >detection of pressure stimulus >production of defensive chemicals >storage of fat >secretion of sweat

>detection of pressure stimulus. Structure B is a lamellar (Pacinian) corpuscle that responds to cutaneous contacts involving deep pressure.

You discover a new type of gland associated with the skin. Chemical analysis of the product shows a secretion has a pH of 4, consists of 99% water, and contains traces of normal electrolytes including urea, vitamin C, and dermicidin. There are no traces of fats or proteins. How would you classify this new gland? >sebaceous gland >eccrine gland >mammary gland >ceruminous gland

>eccrine gland. Eccrine glands produce true sweat, which was described in this scenario.

Which region of the skin is highlighted? (Refer to image #7) >follicle wall >dermis >stratum corneum >epidermis

>epidermis

>Epidermis >Papillary layer >Dermal papillae >Dermis >Hypodermis >Reticular layer

>epidermis->uppermost layer >dermis->papillary layer, dermal papillae re the bumps just underneath epidermis w/ reticular layer underneath (majority of dermis) >hypodermis is lowest layer

Which structure is highlighted? (Refer to image #8) >melanocytes >keratinocyte nuclei >mast cells >fibroblast nuclei

>fibroblast nuclei. This is from dense irregular tissue.

Which structure is highlighted? (Refer to image #4) >hair follicles >external root sheath >eccrine ducts >hair shaft

>hair follicles

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.

In people with lighter skin, respiratory failure can lead to a change in the color of the skin. Which pigmentation factor is affecting this change? >melanin >carotene >folic acid >hemoglobin

>hemoglobin. As the blood becomes hypoxic, hemoglobin is carrying less oxygen. This deoxygenated state leads to the condition known as cyanosis.

What is the most common cell type in the epidermis? (Refer to image 1) >fibroblasts >keratinocytes >dendritic cells >macrophages

>keratinocytes. Keratinocytes are the primary cells that form the stratified layers of the epidermis.

Which structure is highlighted? (Refer to image #6) >papilla >matrix >hair root >follicle

>matrix.

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

>melanin. Melanin is the only one of the three pigments (melanin, carotene, and hemoglobin) that contribute to skin color that is actually produced in the skin itself.

The skin is NOT a __________ barrier. >chemical >metabolic >physical >biological

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

Which type of cell is NOT found in the epidermis? >melanocytes >pain receptors >keratinocytes >dendritic cells

>pain receptors. Pain receptors are found deeper in the papillary layer of the dermis.

This layer of the dermis is responsible for fingerprints. >deep stratum basale >reticular layer >areolar layer >papillary layer

>papillary layer

Which layer of the skin is highlighted? (Refer to image #2) >epidermis >papillary layer of dermis >hypodermis >reticular layer of dermis

>papillary layer of dermis.

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

>scalp. The skin of scalp has hair, which gives it added protection from the damaging ultraviolet rays of the sun.

These glands are found all over the skin except in the palms of the hands and soles of the feet. They produce an oily substance that lubricates skin and hair. >eccrine sweat glands >apocrine sweat glands >endocrine glands >sebaceous glands

>sebaceous glands.

The portion of a hair that projects from the scalp surface is known as the __________. >root >shaft >bulb >matrix

>shaft

What type of tissue is highlighted? >stratified cuboidal epithelium >columnar epithelium >simple cuboidal epithelium >stratified squamous epithelium

>stratified cuboidal epithelium

Which type of tissue is the highlighted region composed of? (Refer to image #9) >stratum spinosum >stratified squamous epithelium, keratinized >stratum corneum >dermis

>stratified squamous epithelium, keratinized. The cells were clearly multilayered, with cuboidal at the base and a sizable layer of squamous cells atop it.

From deep to superficial, the layers of the epidermis of thin skin are ________. >stratum corneum, stratum granulosum, stratum spinosum, stratum basale >stratum basale, stratum spinosum, stratum granulosum, stratum corneum >stratum granulosum, stratum spinosum, stratum corneum, stratum basale >stratum spinosum, stratum basale, stratum corneum, stratum granulosum

>stratum basale, stratum spinosum, stratum granulosum, stratum corneum.

Which layer of the epidermis is highlighted? (Refer to image #5) >stratum spinosum >stratum corneum >stratum basale >stratum granulosum

>stratum spinosum

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

>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 (called cholecalciferol), which is transported via the blood to the liver and kidneys, where it is converted into a hormone called calcitriol, or active vitamin D.

Which of the following is not a function of the skin? >protection >preventing dehydration >synthesizing vitamin C >helping regulate temperature

>synthesizing vitamin C.

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. The epidermis is avascular but highly innervated; the underlying dermis lacks the number of nerve endings but is rich in blood vessels.

What is the function of the secretion from A? (Refer to image #3) >to lubricate hair and prevent infection >to waterproof the epidermis >to cool the body >to provide nourishment for the cells in the hair

>to lubricate hair and prevent infection. Structure A produces sebum, an oily secretion that coats the hairs and prevents infectious agents from penetrating the hair shaft.

Which of these is NOT a function of the layer at D? >to supply cells to replace those lost from the epidermis >to store energy >to loosely connect the skin to underlying tissue >to insulate the body from heat loss

>to supply cells to replace those lost from the epidermis. The hypodermis does not perform this function. Cells to replace those lost in the epidermis are provided by the basal cells of the epidermis itself.