The epidermis is composed of

four principal types of cells

90% of epidermal cells are

tough, fibrous protein that helps protect the skin and underlying
tissues from heat, microbes, and chemicals

What produce lamellar granules, which release a water-repellent
sealant that decreases water entry and loss and inhibits the entry
of foreign materials.

About 8% of the epidermal cells are

a yellow-red or brown-black pigment that contributes to skin
color and absorbs damaging ultraviolet (UV) light

Type of cell that arise from red bone marrow
and migrate to the epidermis, where they constitute
a small fraction of the epidermal cells

Type of cell that participates in
immune responses mounted against microbes that invade the
skin, and are easily damaged by UV light

Langerhans role in the immune
response?

least numerous of the epidermal cells?

Type of cell that are located in the deepest layer of the epidermis

Merkel cells and ___________ discs detect touch
sensations

The deepest layer of the epidermis

stratum basale composed of a single row of?

Superficial to the stratum basale and arranged in 8 to 10 layers of
many-sided keratinocytes fitting closely together.

At about the middle of the epidermis and consists of three to
five layers of flattened keratinocytes that are undergoing
apoptosis

A distinctive feature of cells in this layer is the presence
of darkly staining granules of a protein called

Also present in the keratinocytes are membraneenclosed which release a lipid-rich secretion called what?

present
only in the thick skin of areas such as the fingertips, palms, and
soles

Which layer consists of three to five layers of flattened clear, dead
keratinocytes that contain large amounts of keratin and thickened
plasma membranes.

Which layer consists on average of 25 to 30 layers of flattened dead keratinocytes

Constant exposure of skin to
friction stimulates the formation of a

As the cells move from one epidermal layer to the
next, they accumulate more and more keratin, a process called

The second, deeper part of the skin and composed of
a strong connective tissue containing collagen and elastic fibers is called what?

The ___________ region makes up about one-fifth of the thickness of the total dermis layer

The dermis also has the ability to

Blood
vessels, nerves, glands, and hair follicles (epithelial invaginations
of the epidermis) are embedded in the

The Papillary regions surface area is greatly increased by

Some dermal
papillae also contain tactile receptors called

Which region is attached to
the subcutaneous layer?

reticular region consists of?

The study of the pattern of
epidermal ridges is called

pigments that
impart a wide variety of colors to skin

Which pigment cell is most plentiful in the epidermis of the penis,
nipples of the breasts, area just around the nipples (areolae),
face, and limbs?

the oxygen-carrying pigment in red
blood cells.

yellow-orange
pigment that gives egg yolk and carrots their color.

stored in the stratum corneum and fatty areas of the
dermis and subcutaneous layer in response to excessive dietary
intake

inherited
inability of an individual to produce melanin.

people affected by albinism, have melanocytes that are
unable to

the partial
or complete loss of melanocytes from patches of skin produces
irregular white spots.

buildup of the yellow pigment bilirubin in the skin.

someone who has stopped
breathing, the mucous membranes, nail beds, and skin appear bluish

redness of the skin, is caused by engorgement of capillaries
in the dermis with blood due to skin injury, exposure to heat, infection,
inflammation, or allergic reactions.

paleness of
the skin, may occur in conditions such as shock and anemia.

A substance that removes hair is called

What are present on most skin surfaces except
the palms, palmar surfaces of the fingers, the soles, and plantar
surfaces of the feet

the superficial portion of the hair, which projects above the surface
of the skin

The shaft and root of the hair both
consist of three concentric layers of cells called?

Layer of hair which
may be lacking in thinner hair, is composed of two or three
rows of irregularly shaped cells.

Layer of hair that forms the
major part of the shaft and consists of elongated cells.

the outermost layer, consists of a single layer
of thin, flat cells that are the most heavily keratinized

Surrounding the root of the hair is

downward continuation of the
epidermis is referred to as?

produced by the matrix
(described shortly) and forms a cellular tubular sheath of epithelium
between the external root sheath and the hair

dense
dermis surrounding the hair follicle is called

The base of each hair follicle and its surrounding dermal root
sheath is an onion-shaped structure is called?

the Bulb structure houses a nipple-shaped indentation called?

the papilla of the
hair contains what?

condition which results in the partial or complete
lack of hair, may result from genetic factors, aging, endocrine
disorders, chemotherapy, or skin disease

condition of excessive
body hair

the follicles produce
very fine, nonpigmented, downy hairs called

Prior to birth,
the lanugo of the eyebrows, eyelashes and scalp are shed and replaced
by long, coarse, heavily pigmented hairs called

The lanugo of the rest of the body are replaced by

vellus
hairs are commonly referred to as?

which glan that are also oil
glands which are simple, branched acinar glands.

Sebaceous glands secrete an oily substance called

There are three to four million sweat glands, or also called what?

sudoriferous
glands release what?

Sweat glands are
divided into two main types,

which gland are also known as merocrine sweat glands, are simple,
coiled tubular glands that are much more common than apocrine
sweat glands

which gland is distributed
throughout the skin of most regions of the body, especially in the
skin of the forehead, palms, and soles

The sweat produced by eccrine sweat glands consists of?

Which glandare also simple, coiled tubular glands and
They are found mainly in the skin of the axilla (armpit), groin,
areolae (pigmented areas around the nipples) of the breasts, and
bearded regions of the face in adult males.

Modified sweat glands in the external ear are called

The
combined secretion of the ceruminous and sebaceous glands is a
yellowish material called

what are the
three common forms of skin cancer

which skin cancer account for
about 78% of all skin cancers. The tumors arise from cells in the stratum
basale of the epidermis and rarely metastasize

which skin cancer account for about 20% of all skin cancers, arise
from squamous cells of the epidermis, and they have a variable tendency
to metastasize

which skin cancer arise from melanocytes and account for
about 2% of all skin cancers

Burn involves only the epidermis (Figure 5.9a). It is characterized by mild
pain and erythema (redness) but no blisters.

burn that destroys the epidermis and part of the
dermis (Figure 5.9b). Some skin functions are lost. In a second-degree
burn, redness, blister formation, edema, and pain result.

destroys the epidermis,
dermis, and subcutaneous layer (Figure 5.9c). Most skin functions are
lost. Such burns vary in appearance from marble-white to mahogany
colored to charred, dry wounds.

Skin graft that transplanted skin is usually taken from the same individual

transplanted skin that is taken from identical twin?