chapter five integumentary Flashcards
What are the two layers of the cutaneous membrane (skin)?
epidermis and dermis
What is the most superficial layer of the epidermis?
stratum corneum
What is the subcutaneous layer that separates the integument from the deep fascia around other organs?
hypodermis
Which epidermal layer is found only in thick skin?
stratum lucidium
The secretion that lubricates and inhibits growth of bacteria on the skin is called __________.
sebum
The layers of the epidermis, beginning with the deepest layer and proceeding outward, include the strata __________
germinativum/basale, spinosum, granulosum, corneum
In which layers of the epidermis do mitotic divisions occur?
stratum germinativum and stratum spinosum
Approximately how long does it take for a cell to move from the stratum germinativum to the stratum corneum?
7-10 days
Epidermal cells in the stratum spinosum and stratum germinativum function as a chemical factory in that they can convert __________
steroid precursors to vitamin D3 when exposed to sunlight
Differences in skin color among individuals are the result of __________
the different levels of melanin synthesis
What are the two basic factors interacting to produce skin color?
circulatory supply and pigment concentration
Skin exposure to small amounts of ultraviolet radiation serves to __________
convert a steroid related to cholesterol into vitamin D
Excessive exposure of the skin to ultraviolet radiation may cause redness, edema, blisters, and pain. The presence of blisters classifies the burn as __________
second degree
What are the two layers of the dermis?
papillary layer and reticular layer
Which of the following structures can you find within the dermis?
lymphatics, nerve fibers, blood vessels
Special smooth muscles in the dermis that, when contracted, produce “goose bumps” are called __________
arrector pili
What are the primary tissues composing the hypodermis?
areolar and adipose
The hypodermis is useful for subcutaneous injection by hypodermic needle because it has __________
a limited number of capillaries and no vital organs
An important function of the hypodermis is to __________
stabilize the position of the skin in relation to underlying issues
Hair production occurs in the __________
reticular layers of the dermis
What is the natural factor responsible for varying shades of hair color
type of melanin present
Accessory structures of the skin include the _________
hair follicles and the sebaceous and sweat glands
Sensible perspiration released by the eccrine sweat glands serves to __________
cool the surface of the skin, reduce body temperature, and dilute harmful chemicals
When the body temperature becomes abnormally high, thermoregulatory homeostasis is maintained by __________
an increase in sweat gland activity and an increase in blood flow to the skin
Nail production occurs at an epithelial fold NOT visible from the surface called the _________
nail root
Which of the following statements describes the immediate response by the skin to an injury?
Bleeding occurs, and mast cells trigger an inflammatory response.
The practical limit to the healing process of the skin is the formation of inflexible, fibrous, noncellular __________
scar tissue
Hair turns gray or white because of _________
decreased melanocyte activity
Sagging and wrinkling of the integument is due to __________
a decrease in the elastic fiber network of the dermis
When ruptured dermal blood vessels leak into the dermis, a __________ may form
bruise
What is the name of the pale, crescent-shaped area near the root of the nail?
lunula
Psoriasis is a skin disorder in which there is abnormal increased mitotic activity in the __________
stratum germinativum
How do third-degree burns differ from first- and second-degree burns?
In a third-degree burn, the epidermis, dermis, and hypodermis are destroyed.
What condition causes inflammation in the papillary layer when a part of the skin is exposed to infection or an irritant?
dermatitis
Because fresh water is hypotonic to body fluids, sitting in a freshwater bath causes _________
water to enter the epidermis and cause the epithelial cells to swell
Why are malignant melanomas extremely dangerous and life-threatening?
The melanocytes grow rapidly and metastasize through the lymphatic system.
The core of a hair is called the _________
medulla
Ceruminous glands are modified sweat glands located in the _________
external auditory canal
Yellowing of the fingernails occurs in patients who have ________
chronic respiratory disorders, thyroid gland disorders, or AIDS
Where can you find an apocrine sweat gland?
armpits, nipples, pubic region
The body of the nail __________
consists of dead, tightly compacted cells
Why are lines of cleavage clinically significant?
a cut parallel to the line of cleavage will remain closed
Which of the following functions is NOT associated with the skin?
synthesis of B vitamins
Sebaceous glands release which type of secretion?
sebum
Which of the following are benign tumors that occur in the skin?
warts
A thick, flattened mass of scar tissue that grows into the tissue around an injury site is called __________
keloid
A decrease in the number of __________ leads to increased damage and infection associated with age.
Langerhans cells
The peptide that is secreted by the pituitary gland and increases the rate of melanin production is _________
MSH
When the skin is deprived of blood flow and oxygen, it takes on a bluish coloration called __________
cyanosis
A hair at the end of the growth cycle is called _________
club hair
