Practice Quiz Q’s For Chapter 5 Flashcards
The skin is also known as a (the)________
cutaneous membrane
Which type of epithelium makes up the epidermis?
keratinized stratified squamous
About 90% of the cells of the epidermis are of which type?
keratinocytes
Which layer consists of an average of 25 to 30 layers of flattened dead keratinocytes
stratum corneum
The pigment-producing cells of the epidermis are located in which layer?
stratum basale
Which of the following is not a correct statement about melanin?
a) granules of melanin are produced and exported by melanocytes
b) melanin granules are the source of skin pigmentation
c) melanin is necessary for production of vitamin D by the skin
d) melanin pigment protects DNA from damaging UV light
e) melanin granules are taken up by keratinocytes
C
Which layer has stem cells that undergo cell division to continually produce new keratinocytes?
stratum basale
Which epidermal layer marks the transition between metabolically active cells of lower layers and the dead layers of keratinocytes of the upper layers
stratum granulosum
This skin layer is only present in places subjected to high levels of mechanical wear-and-tear, and provide an additional protective layer where it occurs, such as in the soles of the feet, palms, and fingertips
stratum lucidum
Intraepidermal macrophages are part of the skin’s immune defenses and activate other immune cells when the skin is invaded by microbes. Which layer of the epidermis contains Intraepidermalmacrophages?
stratum spinosum
Which statement is not correct about the dermis?
a) it is made up of dense, irregular connective tissue
b) it is thinner in men than in women
c) it contains collagen and elastinfibers
d) it provides the blood supply and many sensory receptors for the epidermis
e) it has a smaller papillary layer, and a thicker reticular layer
B
Which of the following would be found in the papillary layer but not the reticular layer of the dermis?
capillary loops
Which of the following plays a role in emotional sweating (sweating due to stress or strong emotion, not thermoregulation)?
apocrine glands
Thinner hair may be lacking what structural component of a typical hair?
medulla
The amount and kind of melanin present in the cortex and medulla of a hair shaft determines hair color. When melanin is replaced by air bubbles in the shaft, which is the resulting hair color?
White
The hyponychiumis the __________ of the nail
nail bed
Actual growth of the nail occurs in the ________
nail matrix
The majority of body hair of _______ is vellus rather than terminal hair
Adult females
Along with sweating, which other responses by skin assists with thermoregulation?
blood vessels near the skin can dilate, increasing blood flow and heat loss
Which feature(s) of the skin protect(s) us against microbes such as bacteria?
a) the many layers of keratinized cells form a barrier against microbes
b) sebum contains compounds which kill bacteria
c) sweat has an acidic pH which suppresses microbial growth
d) Intraepidermalmacrophages can alert the immune system should microbes invade
e) all of these are correct
E
Vitamin D, following activation in the skin, is converted to the hormone calcitriol by enzymes in the liver and kidneys. People in northern climates who may not get adequate sun exposure can become deficient in vitamin D. What mineral would be especially affected by this?
Calcium
The skin perceives a variety of sensations from several types of sensory receptors. Which receptor would let a person know if there was a small insect walking across a hair on their arm?
Hair root plexus
When an epidermal wound begins the healing process, basal cells migrate away from the basement membrane, enlarge, and migrate to fill in the wounded area). As these cells migrate from different sides of the wound, and reach each other, they stop migrating. This process is called__________
contact inhibition
During development in the womb, the fetus by the fifth month is covered and protected by a fatty substance called_________
vernix caseosa
In the womb, which is the correct sequence of development for the dermis?
mesoderm→mesenchyme→dermis
The skin is composed of both a superficial epidermis and a deeper dermis. The epidermis is highly vascularized, while the dermis is avascular
False
The cells of the stratum basalebecome more metabolically active and increase their rate of cell division when upper layers of the epidermis are stripped away due to abrasions or burns
True
It takes 4–6 weeks for a keratinocyte to form in the stratum basale, become keratinized in its journey through the upper layers of the epidermis, and to finally be sloughed off as a dead skin cell
True
Dermal papillae give rise to a person’s fingerprints and footprints
False
A skin graft would be needed if a person damaged the upper layers of the skin down to the stratum granulosum
False
Differences in skin pigmentation are due to the number of melanocytes in the basal layer of the skin. People with darker skin have many more melanocytesthan people with paler skin
False
Hair follicles go through a characteristic growth cycle: the growth stage, regression stage, and resting stage. At any given time, about 85% of a person’s hair is in the resting stage of the growth cycle
False
In addition to a thicker stratum corneumand the presence of a stratum lucidum, the thick skin of the palms and fingertips of the hands and of the soles of the feet have a denser array of sense receptors than thinner skin found elsewhere on the body, and also is hairless
True
Water soluble vitamins (B vitamins and vitamin C) can be easily absorbed through the skin, but absorption of the fat-soluble vitamins (vitamin A, D, E and K) is minimal
False
In deep wound healing, an injury has penetrated through to the dermis or even the hypodermis (subcutaneous layer). In this type of wound, the healing process will leave a scar and could involve a loss of some functionality of the area of the wound
True
Wounds that only damage the epidermis won’t bleed because the epidermis is avascular
True
Formation of granulation tissue and a scab would only happen in deep wound healing where the dermis has been damaged
True
With advancing age, the dermis thickens and the formation of surface cells of the epidermis speeds up
False
