Chapter 5 HW
Which of the following functions of the skin explains the skin's pink hue? cutaneous sensation thermoregulation blood reservoir protection
blood reservoir
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 is not true about eccrine/merocrine sweat glands? -They begin to function at puberty -They are found throughout the body -Their excretory duct terminate at the surface of the epidermis -They regulate body temperature
They begin to function at puberty
Wounds that only damage the epidermis won't bleed because the epidermis is avascular. True or False
True
Which might be due to a decrease in the amount of oxygen in the blood? jaundice erythema cyanosis albinism
cyanosis
The use of cotton-tipped swabs is recommended for the removal of impacted cerumen. True or False
False
Which feature(s) of the skin protect(s) us against microbes such as bacteria?
All of these are correct
Which of the following characteristics is associated with malignant melanoma? asymmetry irregular borders diameter larger than a pencil eraser all of these choices
All of these choices
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
Approximately 80% of males experience significant hair loss by age 60. True or False
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 melanocytes than people with paler skin. True or False
False
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. True or False
False
With advancing age, the dermis thickens and the formation of surface cells of the epidermis speeds up. True or False
False
The alternate name for the stratum basale, the stratum __________, suggests its role in forming new cells. -spinosum -granulosum -germinativum -lucidum
Germinativum
About 90% of the cells of the epidermis are of which type?
Keratinocytes
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?
Root hair plexus
Which is not true about melanocytes -They protect the skin from UV rays -They neutralize free radicals formed from exposure to sun -They produce pigments and transfer it to keratinocytes -They undergo rapid mitosis to regenerate skin
They undergo rapid mitosis to regenerate skin
Although they appear in the dermis, hair follicles are derived from the epidermis True or False
True
Because of the new arrangement of collagen fibers and the scarcity of blood vessels, scars are usually lighter in color than normal skin. True or False
True
Examination of the nail beds and gums of the mouth are diagnostic tools for anemia in dark skinned individuals. True or FalseT
True
Formation of granulation tissue and a scab would only happen in deep wound healing where the dermis has been damaged. True or False
True
In a few locations (tarsal glands of the eyelids, the head of the penis, the lips, etc)), sebaceous glands release sebum directly onto the surface of the skin. True or False
True
In addition to a thicker stratum corneum and 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 or False
True
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 or False
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 or False
True
The accumulation of melanin into freckles is a genetic trait. These patches of pigmentation tend to darken with sun exposure and fade during the winter when there is less exposure to the sun. True or False
True
The cells of the stratum basale become 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 or False
True
The majority of body hair of _________ is vellus rather than terminal hair.
adult females
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
The skin is also known as a (the)
cutaneous membrane
Which of the following would not be a change to the skin that occurs with aging?
formation of lanugo
Which is the correct sequence of phases for deep wound healing? inflammation, proliferation, migration, maturation inflammation, migration, proliferation, maturation proliferation, inflammation, migration, maturation proliferation, migration, inflammation, maturation
inflammation, migration, proliferation, maturation
Which statement is not correct about the dermis?
it is thinner in men than in women
Which type of epithelium makes up the epidermis?
keratinized stratified squamous
Which of the following is not a correct statement about melanin?
melanin is necessary for the production of vitamin D by the skin
In the womb, which is the correct sequence of development for the dermis?
mesoderm → mesenchyme → dermis
The hyponychium is the __________ of the nail.
nail bed
Actual growth of the nail occurs in the __________ .
nail matrix
The pigment-producing cells of the epidermis are located in which layer?
stratum basale
Which layer has stem cells that undergo cell division to continually produce new keratinocytes?
stratum basale
Which layer consists on average of 25 to 30 layers of flattened dead keratinocytes.
stratum corneum
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
Langerhans cells 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 Langerhans cells?
stratum spinosum
During development in the womb, the fetus by the fifth month is covered and protected by a fatty substance called __________ .
vernix caseosa
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
