A&P Exam 1 Ch. 5
When a person becomes "pale," what is the physiologic basis?
The blood supply to the skin decreases
What is the function of melanin?
It protects DNA from the damaging effects of ultraviolet radiation.
This layer is composed of a high concentration of collagen fibers.
dermis
A small amount of ultraviolet radiation is beneficial because it
stimulates vitamin D3 synthesis in the epidermis
The layer of the epidermis at the exposed surface is the
stratum corneum
Mammary glands are modified
sweat glands
When the arrector pili muscles contract,
"goose bumps" are formed
Why are injections administered in the hypodermis when administering drugs using a hypodermic needle?
Since it is vascularized, the hypodermis can absorb a lot of fluid.
The condition that results from clogged sebaceous glands is
acne
In other mammals, the ________ glands function as scent glands, providing an important form of communication.
apocrine
The glands that begin discharging a sticky, cloudy, and potentially odorous secretion at puberty are called ________ glands.
apocrine
The subcutaneous layer consists of
areolar and adipose tissues
What is the composition of the papillary layer of the dermis?
areolar connective tissue
The ________ is associated with the puckering of skin and the pulling of the hair follicle.
arrector pili
Which of the following conditions is the most common form of skin cancer?
basal cell carcinoma
The nail ________ covers the nail bed.
body
Exposure of the skin to ultraviolet light
can increase melanocyte activity
Glands that are located in the passageway of the external ear are called ________ glands.
ceruminous
The blood supply to the skin arises from a network of blood vessels called the ________ plexus in the hypodermis, at its border with the reticular layer of the dermis.
cutaneous
The skin is also called the ________ membrane
cutaneous
The fold of stratum corneum over the base of a nail is called the
cuticle
Shafts of hair are comprised of
dead, keratinized epidermal cells
The dermis is composed largely of
dense irregular connective tissue
Projections of loose connective tissue from the dermis, which extend upward between the adjacent ridges of the epidermis, are called
dermal papillae.
Epidermal cells are supplied with nutrients from blood vessels in the
dermis
The highly vascular layer of the skin, which provides thermoregulation via changing blood flow, is the
dermis
Which of the following is the correct order of the layers of the cutaneous membrane?
dermis, dermis, hypodermis
When the body is overheated, the skin responds by
dilating blood vessels
The most mitotically active part of the skin is structure
epidermis
The walls of each hair follicle contain all the cell layers found in which of the following?
epidermis
Thin skin is defined by the thickness of the
epidermis
Through which mechanism does perspiration function in cooling the body?
evaporation
Hair is formed by the repeated divisions of epithelial stem cells in which structure?
hair matrix
Through which cellular interactions are the cells of the stratum basale firmly attached to the plasma membrane?
hemidesmosomes
The lipid in oil glands is released through which type of secretion?
holocrine
Lipid is concentrated with the cells of the
hypodermis
Perspiration that is produced by apocrine sweat glands
is limited to the hair follicles of the axilla, nipples, and groin.
A hair shaft is composed of
keratin
The protein that contributes to many of the skin's protective qualities is called
keratin
The function of the secretion of a sebaceous gland is
lubrication
The pale crescent area of the nail is called the
lunula
Modified and specialized sweat glands that produce milk are called ________ glands.
mammary
In albinism, ________ is lacking
melanin
The observed differences in skin color reflect the levels of ________ production
melanin
The most severe type of skin cancer is most likely to develop from
melanocytes.
Nerve fibers in the dermis most likely function in
monitoring sensory receptors in the dermis.
You have been severely burned on the right arm in a house fire, but you are now recovering. The second- and third-degree burns have destroyed the epidermis and dermis of your arm. Predict the long-term consequences of this burn.
no growth of hair in the damaged skin area
Drugs suspended in ________ or ________ can be carried across the plasma membranes of the epidermal cells.
oils; lipid-soluble solvents
The reticular layer's collagen fibers directly provide which function?
prevent damage to the tissue
Which of the following is the function of hair associated with a nerve fiber?
provides an early-warning system that may help prevent injury
Functions of the skin include
regulating body temperature
Merocrine sweat glands
respond primarily to elevated body temperature.
The ________ layer of the dermis contains bundles of collagen fibers and elastin, and is responsible for the mechanical strength and flexibility of the skin.
reticular
Elderly people tend to have rougher skin and more brittle hair than younger people. What structure is associated with this problem?
sebaceous glands
The epidermal layer whose cells have stopped dividing and started to produce large amounts of keratin is the
stratum granulosum
As cells are pushed from the deeper portion of the epidermis toward the surface,
they die
Melanin serves to protect cells in the deeper layers of the epidermis from
ultraviolet radiation.
Epidermal cells synthesize this vitamin when exposed to sunlight
vitamin D3
Which statement is true for merocrine sweat glands?
They are more numerous than apocrine sweat glands
The loose connective tissue that separates the integument from deeper tissues and organs is called the
hypodermis
Which of the following is the function of the combination of epidermal ridges and dermal papillae?
increase surface area for diffusion between the dermis and epidermis
The hypodermis
is quite elastic
Thick skin can be found on the
palms
Choose the correct order of the cell layers, or strata, in a section of thick skin, from the basement membrane toward the free surface (deep to superficial). 1. stratum lucidum 2. stratum basale 3. stratum corneum 4. stratum granulosum 5. stratum spinosum
2, 5, 4, 1, 3
The function of the arrector pili is
contraction
The skin may turn orange as a result of ________ buildup
carotene
________ is a pigment found in vegetables that can make skin appear orange or yellow.
carotene
The deepest layer of cells in the epidermis is the cells of the
stratum basale