chapter five: integumentary system check your understanding
which layer of the dermis is responsible for producing fingerprint patterns?
papillary layer of the dermis
you go to the beach to swim in extremely hot, sunny afternoon. Describe two ways in which your integumentary system acts to preserve homeostasis during your outing
The integumentary system preserves homeostasis in the body by regulating temperature and water loss on a hot day. The body temperature is kept stable by the production of sweat, which cools the body as it evaporates on the skin's surface. The sweat glands can release between one and two liters of water per hour (The Integumentary System). In hot weather, up to four liters of water can be lost per hour by a combination of sweating and evaporation. Exocrine sweat glands are controlled by the sympathetic nervous system, and occur all over the body. They open to the skin surface through the pores. Apocrine sweat glands are larger, and occur in the armpits and groin areas. They produce a solution that bacteria act upon to produce body odor. Blood vessels in the skin dilate to allow heat loss from the body and help it stay at normal temperature. Sweat gland function and vasodilation/vasoconstriction are controlled by the hypothalamus. It responds to heat and cold receptors located in the skin.
sebum a. lubricates the surface of the skin and hair b. consists of cell fragments and fatty substances c. in excess may cause seborrhea d. all of these
all of these
skin color is determined by a.the amount of blood. b.pigments c.oxygenation level of the blood d. all of these
all of these
the product of this type of sweat gland includes protein and lipid substance that become odoriferous as a result of bacteria action: a. apocrine gland b. eccrine gland c.sebaceous gland d. pancreatic gland
apocrine gland
you have just gotten a paper cut. it is very painful, but it doesn't beeld. has the cut penetrated into the dermis or just the epidermis?
bc no bleeding the cut only penetrated the avascular epidermis
why are nails so hard?
because of keratin
an arrector pili muscle a. is associated w/ each sweat gland b.can cause a hair to stand up straight c. enables is hair to be stretched when wt d. provides new cells for continued growth of its associated hair
can cause a hair to stand up straight
what color does carotene impart to the skin
carotene-yellow orange color, precursor of vitamin A (vision), excess stores in skin which can make you look orange
what are the concentric regions of hair shaft, from the outside in?
cuticle, cortex, medulla
what is cyanosis and what does it indicate?
cyanosis is a bluish cast of the skin that indicated hemoglobin in the red blood cells in the dermal capillaries is poorly oxygenated
why does the skin wrinkle and what factors accelerate the wrinkling process ?
degeneration of the skin is accelerated by excessive exposure to ultraviolet radition of sunlight. this photoaging accounts for more than 90% of changes that ppl find medically troubling or cosmetically disagreeable; skin cancer; yellowing and mottling of the skin; age spots, which resemble enlarged freckles on the back of the hands and other sun exposed areas; and wrinkling, which affects most exposed areas of skin ((face, hands, and arms) sun damaged skin shows malignant and premalignant cells, extensive damage to the dermal blood vessels and denses masses of coarse, frayed elastic fibers underlying surface wrinkles and creases
which cell functions as part of immune system? a. keratinocyte b. melanocyte c. dendritic cell d. tactile cell
dendritic cell
which layer of the skin- dermis or epidermis- is better nourished?
dermis - a connective tissue which is vascular
which tissue of the hypodermis makes it a good shock absorber?
fatty tissue in the hypodermis gives it insulating and shock-absorbing properties
skin surface markings that reflect points of tight dermal attachment to underlying tissues are called a.tension lines b.papillary ridges c.flexure lines d.dermal papillae
flexue lines
what is the function of the hair papilla?
hair papilla contains a knot of capillaries that supplies nutrients to cells of the hair bulb
what is the difference between heat-induced sweating and a "cold sweat" and which variety of sweat gland is involved?
heat-induced sweating occurs all over the body when we are overheated cold sweat is emotionally induced begin in palms,soles, and armpits both types of sweats are produced by eccrine sweat gland but activity of apocrine sweat glands is likely during cold sweat
Melanin and carotene are two pigments that contribute to skin color. what is the third and where is it found?
hemoglobin
when anthony returned home from a run in 85 degrees fahrenheit weather, his face wa dripping with sweat. why?
his sympathetic nervous system activated his eccrine sweat glands and caused heat-induced sweating in order to cool the body.
which is not a true statement about the papillary layer of the dermis? a. it is largely areolar connective tissue b.it is most responsible for thoughness of the skin c.it conatins nerve endings that respod to stimuli d. it is highly vascular
it is most responsible for toughness of the skin
sebaceous glands are not found in thick skin. why is their absence in those body regions desirable?
it would be dangerous to have oily soles, palms, it would decrease the ability of the hands to hang onto things
which alteration in skin color may indicate the liver disorder?
jaundice
the epidermis provides a physical barrier due largely to the presence of a. melanin b.carotene c.collagen d.keratin
keratin
which epidermal cell type is most numerous? select all that apply: a. keratinocyte b. melanocyte c. dendritic cell d. tactile cell
keratinocyte
what is the role of an arrector pili muscle?
pull the hair to the upright position
which cutaneous glands are associated with hairfollices?
sebaceous(oil) glands and apocrine glands
which of the following is not an epidermal derivative? a. hair b.sweat gland c. sensory receptor d. sebaceous gland
sensory receptor
when blood vessels in the dermis constrict or dilate to help maintain body temperature, which type of muscle tissue acts as the effector that causes blood vessel dilation or constriction?
smooth muscle
the stratum basale is also called the stratum germinativum, a name that refers to its major function, what is that function?
stratum basale undergoes almost continuous mitosis to replace cells lost by abrasion
while walking barefoot in a barn, jeremy stepped on a rusty nail that penetrated the epidermis on the sole of his foot. Name the layers the nail pierced from the superficial skin surface to the junction w/ the dermis?
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale
how is sunlight important to bone health?
sunlight is the precursor for vitamin d , which is essential for calcium absorption
the sensation of touch and pressure are picked up by receptors located in a.stratum spinosum b. the dermis c. the hypodermis d.stratum corneum
the dermis
which epidermis cells play a role in body immunity?
the epidermal dendritic cells
what chemicals produced in the skin help provide barriers to bacteria? list at least three
the low ph of skin secretions (acid mantle) inhibits division of bacteria, many bacteria are killed by dermcidin defensins produced by skin cells. cathelicidins effective against strep bacteria.
why is the lunule of a nail white instead of pink like the rest of the nail?
the lunule is white bc the thick nail matrix that underlies it blocks the rosy color of the dermal blood supply from showing through
why are the desmosomes connecting the keratinocytes so important?
the skin is subject to a lot of abrasion and physical trauma, the desmosomes help to hold the cells together during such stress
why is having your hair cut painless?
there are no nerves in a hair so its painless