ch 5 – the integumentary system

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

Layers B and C collectively form the __________.

Section of the integument with labeled histological levels.

subcutaneous layer
hypodermis
epidermis
dermis

dermis

Layer B is composed primarily of __________.

Section of the integument with labeled histological levels.

dense regular connective tissue
areolar connective tissue
dense irregular connective tissue
simple squamous epithelium

areolar connective tissue

Part complete
Which of the following terms describes layer D?

Section of the integument with labeled histological levels.

epidermal
papillary
reticular
subcutaneous

subcutaneous (The hypodermis ("under the skin") layer is also referred to as the subcutaneous region.)

Which of the following correctly describes a common feature of all structures labeled A through D in the figure?

Section of the integument with labeled accessory structures.

Structures A, B, C, and D are located in the dermis.
Structures A, B, C, and D are composed primarily of smooth muscle.
Structures A, B, C, and D are all various types of glands.
Structures A, B, C, and D are all involved in the sensory functions of the skin.

Structures A, B, C, and D are located in the dermis.

What is the most common cell type in the epidermis?

macrophages
dendritic cells
keratinocytes
fibroblasts

keratinocytes

Cell division would be most common among cells in which of the labeled layers?

Section of the epidermis indicating epithelial layers and cell types.

A
B
C
D

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

Which skin-color-associated, pigment-producing cell is located in the labeled layer D?

Section of the epidermis indicating epithelial layers and cell types.

Merkel cell
melanocyte
keratinocyte
fibroblast

melanocyte

What is the structure indicated by label E?

the hypodermis
a hair root
the stratum corneum
a dermal papilla

a dermal papilla (Dermal papillae are projections of the dermis that form indentations in the overlying epidermis.)

Which stratum of the epidermis contains the stem cells responsible for regenerating the more superficial layers?

stratum spinosum
stratum corneum
stratum granulosum
stratum basale

stratum basale

Which skin pigment is made in the skin as a natural defense against UV radiation?

melanin
hemoglobin
carotene
keratin

melanin

Which of the following is a layer of the epidermis found in thin skin?

clear layer
papillary layer
reticular layer
granular layer

granular layer

Which of the following statements is INCORRECT?

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

Tactile cells anchor the skin to the underlying structures of the body.

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.
The secretions of apocrine sweat glands contain more fat and protein than do the secretions of eccrine sweat glands.
Eccrine sweat glands begin to function at puberty, while apocrine sweat glands function throughout life.
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.

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.

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

In alopecia, new hair growth stops because cell division is inhibited in the_________.

epithelial root sheath
cuticle
hair matrix
hair follicle receptor

hair matrix

Which glands secrete an oily product that softens the skin and hair?

apocrine sweat glands
sebaceous glands
ceruminous glands
eccrine sweat glands

sebaceous glands

Earwax is made by __________.

sebaceous glands
eccrine glands
ceruminous glands
mammary glands

ceruminous glands

Which of the following is NOT a function of sebum?

protection from UV radiation
protection from bacteria
lubrication of the skin
prevention of water loss

protection from UV radiation

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 lucidum
stratum granulosum
stratum spinosum

stratum basale

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.

true
false

false

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

What is the function of structure B?

Section of the integument with labeled accessory structures.

detection of pressure stimulus
storage of fat
production of defensive chemicals
secretion of sweat

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

Which of the following is a metabolic function of skin?

cutaneous sensation
elimination of nitrogenous wastes
body temperature regulation
synthesis of a vitamin D precursor

synthesis of a vitamin D precursor

The skin is not a __________ barrier.

biological
metabolic
chemical
physical

metabolic

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

True
False

false

The most dangerous type of skin cancer is __________.

basal cell carcinoma
squamous cell carcinoma
melanoma
All of these skin cancers are equally dangerous.

melanoma

Which of the following would be a sign of a melanoma?

a size smaller than 6 mm
uniform coloration
regular borders
asymmetry

asymmetry

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

In general, skin cancer is least likely to develop in which of the following locations?

scalp
forehead
nose
the back of the hand

scalp

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.)

What is the role of the hair matrix?

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

The hair matrix produces hair.

Which of the following explains why eyebrows do NOT grow as long as the hair on the head?

The hair follicles in the scalp have a hair matrix, but the hair follicles of the eyebrows do not.
The hair follicles in the scalp are responsive to androgens, however the hair follicles of the eyebrows are 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 hairs on the head have a cuticle, whereas the hairs of the eyebrows do not.
The hair follicles of the eyebrows exhibit a resting phase, but the hair follicles in the scalp 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.

Which of the following does NOT protect the skin from bacteria?

the low pH of the skin
the temperature of the skin
dermcidin
defensins
cathelicidins

the temperature of the skin

Which of these is NOT a function of the layer at D?

Section of the integument with labeled histological levels.

to supply cells to replace those lost from the epidermis
to loosely connect the skin to underlying tissue
to store energy
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.)

Which of these structures is properly matched with its mode of secretion?

Section of the integument with labeled accessory structures.

A; holocrine
A; eccrine
B; apocrine
C; holocrine

A; holocrine (Structure A is a sebaceous gland that secretes oily materials by complete rupture of the gland cells.)

What is the function of the structure at A?

Section of the integument with labeled accessory structures.

to lubricate hair and prevent infection
to detect touch
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.)

What feature of the prickle cells in layer C causes them to have pointy projections after tissue preparation?

Section of the epidermis indicating epithelial layers and cell types.

pulling by shrunken keratin fibers between the cells
the rigidity of the cell membrane
glycolipids that make the layer waterproof
their desmosome attachments

their desmosome attachments (Cells typically shrink during tissue preparation, and since these cells are attached by desmosomes, the membranes are pulled slightly outward at the points of cellular attachment.)

Which of these epidermal layers would be LEAST likely to develop cancer?

Section of the epidermis indicating epithelial layers and cell types.

A
C
D
E

A stratum corneum (Cell of this layer are dead and do not participate in mitosis.)

Why does your skin remain red after a bad sunburn?

Inflammation causes increased blood flow.
Damaged epidermis cells are sloughed off.
Loss of sweat glands in the dermal layer
Blisters form, lifting the epidermal layer.

Inflammation causes increased blood flow.

Why would a third-degree burn be less painful than a first- or second-degree burn involving the same body area?

destruction of underlying pain receptors
Inflammatory fluids disrupt nerve endings.
Intense heat alters sensory nerve fibers.
Localized dehydration results in less pain.

destruction of underlying pain receptors