A+P Ch 6

Another type of baldness is ____________, in which the body manufactures antibodies that attack the hair follicles.

alopecia areata

Pattern baldness is called ___________ because it's associated with testosterone, an androgenic (male) hormone.

androgenic alopecia

Other glands, known as _________, become active at puberty, secrete by exocytosis, and wet certain areas of the skin when someone is emotional. They are most numerous in the axillary region and the groin

apocrine glands

The secretion from ______ glands are metabolized by skin bacteria and develops a scent or odor as a result.

apocrine sweat

Skin health relates to skeletal health because vitamin D, whose precursor is produced by skin cells, facilitates absorption of the mineral

calcium

_________ of the external acoustic meatus are modified apocrine sweat glands that secrete cerumen (ear wax) which mixes sebum from nearby sebaceous glands, making a sticky substance that helps prevent entry of microbes and other foreign substances

ceruminous glands

Extensive production of ______ after a skin injury that affects deeper layers often results in the formation of a scar.

collagen

With age, the dermis loses depth as a synthesis of ______ decreases.

collagen and elastin

A skin fold at the proximal end of the nail is the ____________, a portion of the stratum corneum that extends slightly over the nail

cuticle

When blood concentration is low, hemoglobin is dark red, and the skin appears bluish-a condition called ___________

cyanosis

The transferring of melanin granules into neighboring keratinocytes is a process called ____________, which darkens the cells

cytocrine secretion

The ______________, located between the stratum granulosum and the stratum corneum, is in the thickened skin of the palms of the hands and the soles of the feet, where it may be 0.8-1.4 mm thick

stratum lucidum

Sweat glands, also called ________, are widespread in the skin

sudoriferous glands

What type of skin secretion serves an excretory function, ridding the body of small amounts of wastes such as urea and uric acid?

sweat

__________ is mostly water, but it also contains small amounts of salts and wastes such as urea and uric acid. Thus, this can be considered an excretory function.

sweat

Cancer called cutaneous carcinoma originates with what cell type?

basal

a bundle of smooth muscle cells, forming the _________________, attaches to the hair follicle. When the muscle contracts, a short hair in the follicle stands on end.

arrector pili muscle

Merocrine sweat glands

-Description: abundant sweat glands with odorless secretion -Function: lower body temp -location: originate in deep dermis or subcutaneous layer and open to surface on forehead, neck, and back

sebaceous glands

-Description: groups of specialized epithelial cells -Function: keep hair soft, pliable, and waterproof -location: near or connected to hair follicles, everywhere but on palms and soles

A ____________ anchors the epidermis to the dermis and separates these two skin layers

basement membrane

the skin is also known as the __________

cutaneous membrane

Within the stratum spinosum, phagocytes called ____________ act to protect the skin and deeper tissues from pathogen invasion.

dendritic cells

What variation in melanin accounts for the differences in skin tone between individuals?

differences in the amount of melanin produced

The superficial layer, called the __________, is composed of stratified squamous epithelium. The deep inner layer, or __________, is thicker than the epidermis and is made up of connective tissue containing collagen and elastic fibers, along with smooth muscle, nervous tissue, and blood and lymphatic vessels

epidermis, dermis

Nails are produced by the division and keratinization of what type of cells?

epithelial cells

The skin includes two distinct layers:

epithelial tissue overlying connective tissue

Skin color is largely due to melanin, primarily the brownish-black __________ in the epidermis

eumelanin

environmental factors of skin color

exposure to sunlight, UV light from sunlamps, or x-rays increase melanin production and darken melanin granules that are already present

Wound-healing slows with age as the number of ______ decreases.

fibroblasts

Any burn that injures only the epidermis is a superficial partial-thickness (__________) burn. Healing usually takes a few days to two weeks with no scarring

first degree

The cell membranes of older epidermal skin cells thicken and develop many desmosomes that fasten them to each other. At the same time, these older cells begin to harden in a process called _____________

keratinization

Not visible from the surface is the _____________, a thickened area at the proximal end of the nail bed that is the most active growing region. The epithelial cells here divide, and the newly formed cells become heavily keratinized, giving rise to tiny, keratinized scales that become part of the nail plate, pushing it forward over the nail bed.

nail matrix

What is the specific name of the keratinized part of the fingernail or toenail?

nail plate

Each nail consists of a ____________(or nail body) that overlies a surface of the skin called the ____________

nail plate, nail bed

____ are protective coverings on the ends of the fingers and toes.

nails

Skin becomes drier with age due to a decrease in ______.

oil production by sebaceous glands

A fungal infection called __________ produces a variety of changes to nails, such as white or yellow streaks or free edge crumbling, depending on the type of fungus

onychomycosis

How do physiological factors influence skin color?

oxygen content and the state of vasodilation of blood vessels of dermal blood also influences skin color; oxygen-rich blood and dilated blood vessels produce a pinkish tone, and oxygen-poor blood appears bluish through the skin. Diseases can also affect skin color. Albinism, a hereditary condition, affects skin color through the production of abnormal melanin, which causes the skin and hair to be white

the reddish-yellow ____________ is found in certain locations, such as the lips.

pheomelanin

what are the layers of the dermis (superficial to deep), and what type of connective tissue is found primarily in each layer?

The dermis consists of 2 layers: the outer, thinner papillary layer, and the inner, thicker reticular layer. The papillary layer consists of areolar connective tissue, and the reticular layer consists of dense irregular connective tissue

identify the structures found in the dermis

The dermis contains smooth muscle fibers, blood vessels that supply the skin, sensory and motor nerve cell processes, sensory receptors, and accessory structures, such as nails, hair follicles, sweat glands, and sebaceous glands

name the major (primary) tissue types found in the layers of the skin

The epidermis, the outer layer, consists of epithelial tissue. The dermis, the inner layer, consists of connective tissue

people who inherit mutations in melanin genes have a condition called __________, includes nonpigmented skin and is possible in people of all races

albinism

In ___________, heat moves from the body directly into the molecules of cooler objects in contact with its surface

conduction

What is the composition of the epidermis?

consists of stratified squamous epithelium and lacks blood vessels

as air becomes heated, it moves away from the body, carrying heat with it, and is replaced by cooler air moving toward the body. This type of continuous circulation of air over a warm surface is called

convection

Skin cancers originating from epithelial cells are called ____________, while those arising from melanocytes are called ___________

cutaneous carcinomas, cutaneous melanomas

_____ affects skin color. For example, consuming high amounts of yellow vegetables may turn skin orange-yellow because these foods are rich in a pigment called __________. The skin color results from accumulation of this in the adipose tissue of the dermis and subcutaneous layers.

diet, carotene

The secretion released by sebaceous glands are ______ secretions.

fatty

The keratin of nails is stronger than that produced by the stratum corneum. In time, the plate extends beyond the end of the nail bed, forming the __________

free edge

If a person is emotionally upset or very cold, nervous stimulation causes the arrector pili muscle to contract, producing gooseflesh, or _______

goose bumps

A __________ is composed of dead epithelial cells

hair

The deepest portion of the hair root, located at the base of the hair follicle is called the _____________

hair bulb

each hair develops from a group of epidermal stem cells at the base of a tubelike depression called a ____________

hair follicle

within the hair bulb is the ___________, where the epithelial cells divide and growth occurs.

hair matrix

When the body temp is higher than 38.5 C, it's called _________, but it's called _________ when it's below 35 C

hyperthermia, hypothermia

Subcutaneous injections and intramuscular injections, administered into muscles, are also called ____________ injections

hypodermic

The epidermis is composed of stratified ____________________________, while the thicker dermis is made of ___________ tissue, along with muscle tissue, nervous tissue, and blood and lymphatic vessels.

squamous epithelium, connective

___________ injections are administered through a hollow needle into the subcutaneous layer beneath the skin

subcutaneous

There is no distinct boundary that separates the dermis and the ____________

subcutaneous layer

beneath the dermis, and not part of the skin, is the ______________, or hypodermis. This layer is composed of areolar and adipose connective tissues that bind the skin to underlying organs.

subcutaneous layer

Stratum spinosum

-beneath the stratum granulosum -many layers of cells with centrally located, large, oval nuclei and developing fibers of keratin; cells becoming flattened

Stratum basale

-deepest layer of the epidermis -a single row of cuboidal or columnar cells that divide and grow, this layer also includes melanocytes

the following are included in the integumentary system

-hair and nails -sebaceous and sweat glands -the skin

When sebaceous glands are overactive and skin cells block their ducts, the condition called ________ results

Acne

What is the typical treatment for newborns with jaundice?

Exposure to ultraviolet lights breaks the bilirubin down.

True or false: The number of melanocytes in a person's skin determines how dark their skin tone will be.

False

The ___________ contains large blood vessels, with branches forming a network (rete cutaneum) between the dermis and the subcutaneous layer. They, in turn, give off smaller vessels that supply the dermis and the underlying adipose tissue

Subcutaneous layer

what are the modified apocrine glands?

the modified sweat glands are the mammary glands and the ceruminous glands

What is the most actively growing region of the nail?

the nail matrix

Explain how a hair forms

A hair forms from stem cells found inside a depression of the epidermis called a hair follicle. As the stem cells divide and grow, the older cells are pushed outward toward the surface of the skin. The growing hair is nourished by blood vessels in a mass of connective tissue that projects into the base of the hair; this is called the hair papilla. As the cells migrate outward, they form the hair shaft.

What is the purpose of a scab and how does it slough off?

A scab covers the underlying tissue of a wound, and protects it while it's healing. The scab sloughs off as epidermal tissue is replaced and migrates outward, just like normal migration and shedding of normal tissue of the epidermis

Describe the structure of the nail bed

The nail bed is a thin layer of skin under the hardened nail plate. It's produced by epithelial cells that are continuous with those of the nearby skin. The nail matrix is a thickened region at the proximal end of the nail bed; it's the most active growth area of the nail. The dividing cells of the nail matrix develop a large amount of keratin, forming keratinized scales that are incorporated into the nail plate

List the layers of skin from superficial to deep

The skin consists of two layers: the outer layer is the epidermis and the inner layer is the dermis

Stratum basale vs stratum corneum

The stratum basale is the innermost layer of the epidermis. It consists of a thin layer of dividing cells, which are nourished by the underlying blood vessels of the dermis. The stratum corneum is the outermost layer of the epidermis. It consists of many layers of dead, flattened, dehydrated, densely packed, keratinized cells.

What are the functions of the subcutaneous layer?

The subcutaneous layer binds the skin to the deeper organs, insulates the body from heat loss, and supplies the skin with major blood vessels for nutrient and oxygen delivery

Which type of burn is most likely to leave a scar and why?

a full-thickness burn is most likely to leave a scar, because of the epithelial cells have been destroyed and healing from the cells on the margins is not very effective. The fibroblasts and collagen framework are also destroyed in this type of burn

Both ______ and ______ glands release their secretions into hair follicles.

apocrine, sebaceous

if the injured area of a full thickness burn is extensive, treatment may require removing a thin layer of skin from an unburned region of the body and transplanting it to the injured area. This procedure is an example of a ____________, a transplant within the same individual

autograft

What forms the fingernails and toenails?

keratinized epidermal cells

the part of the nail matrix that's seen as a whitish, half-moon-shaped region called the _________

lunula

What area(s) of the body lack(s) sebaceous glands?

palms and soles

Explain the role of phagocytic cells in wound healing

phagocytic cells help heal wounds by engulfing and destroying pathogens, and removing dead body cells and debris from the area

Dilation (vasodilation) of blood vessels of the dermis gives most fair skin a ______ coloration.

reddish

During and following the healing of an injury, extensive production of collagen results in the formation of an elevation above the normal epidermal surface called a ______.

scar

_____________ contain groups of specialized epithelial cells and are usually associated with hair follicles. They are holocrine glands and their cells produce globules of a fatty material that accumulate, swelling and bursting the cell

sebaceous glands

The oily mixture secreted by sebaceous glands is called

sebum

The production of new skin cells in what layer typically keeps pace with the loss of cells from the stratum corneum?

stratum basale

Which layer of the epidermis contains melanocytes?

stratum basale

cells in the deepest layer of the epidermis, called the ____________, or stratum germinativum, are nearest to the dermis and are nourished by dermal blood vessels

stratum basale

Which two factors explain the visible age-related changes in the skin, including sagging and wrinkles?

the shrinking of the dermis loss of adipose tissue from the hypodermis

Name the tissues in the subcutaneous layer beneath the skin.

the subcutaneous layer contains areolar connective tissue and adipose tissue

Apocrine sweat glands

-Description: less numerous sweat glands with secretions that develop odors -Function: wet skin during pain, emotional upset, fear, and sexual arousal -location: near hair follicles in armpit and groin

ceruminous glands

-Description: modified sweat glands -Function: secrete ear wax -location: external acoustic meatus

mammary glands

-Description: modified sweat glands -Function: secrete milk -location: breasts

Which three structures are sensory receptors found in the skin?

-Meissner tactile corpuscles -free nerve endings -Pacinian lamellated corpuscles

Layers of epidermis from superficial to deep

-Stratum corneum -stratum lucidum (only in thick skin) -stratum granulosum -stratum spinosum -stratum basale

Which two items describe a scab, such as would occur after a deep cut to the skin?

-a blood clot -dried tissue fluids

What tissues are present within the subcutaneous layer?

-adipose tissue -loose connective tissue

stratum granulosum

-beneath the stratum corneum -three to five layers of flattened granular cells that contain shrunken fibers of keratin and shriveled nuclei

Which three of the following factors can affect skin color?

-blood oxygenation -blood perfusion -diet

What three symptoms may occur during severe hypothermia?

-lethargy, loss of reflexes -loss of consciousness -mental confusion

Contraction and relaxation of smooth muscle fibers in the dermis influence what two characteristics of the skin?

-loss and conservation of heat -the surface area of the skin

Which of the following are areas of the body where hair is not present on the skin?

-nipples -soles -palms

stratum lucidum

-only present in thick skin (soles and palms) -between stratum corneum and stratum granulosum -cells appear clear; nuclei, organelles, and cell membranes are no longer visible

What are the two protective functions of sebum?

-prevents water loss -contains an anti-microbial compound

Sweat secreted from merocrine sweat glands contains what three main components?

-salts -urea -water

What tissues are found in the skin?

-stratified squamous epithelium -dense irregular connective tissue -adipose tissue -blood tissue -muscle tissue -nervous tissue -areolar connective tissue

stratum corneum

-superior (outermost) layer -many layers of keratinized, dead epithelial cells that are flattened and non-nucleated

Indicate the functions of the subcutaneous layer.

-temperature homeostasis -anchoring the skin to the underlying tissue -supplying the skin with nutrients and gas exchange

What items describe the basement membrane of the skin?

-the boundary between the dermis and epidermis -anchors the stratum basale to the dermis

Put the following steps of fever development in the correct order, starting with the first step at the top.

1. An infectious agent stimulates phagocytes 2. phagocytes release interleukin-1 3. Interleukin-1 stimulates the hypothalamus 4. The hypothalamus stimulates effectors 5. Blood flow to skin increases, sweat glands are inhibited, skeletal muscles increase heat production

Place the steps in the formation of a scab in the correct order starting at the top.

1. an injury occurs that extends into the dermis 2. blood vessels break 3. a blood clot forms 4. tissue fluid seeps into the area and dries out

Place the steps in the production of vitamin D as they occur, starting at the top

1. production of dehydrocholesterol in skin cells 2. production of cholecalciferol with the help of sunlight 3. production of calcitriol in liver and kidney cells

___________ of the subcutaneous layer acts to insulate, which helps conserve body heat.

Adipose tissue

What is the function of an allograft in treating a burn?

An allograft is a graft from another person. To help heal a large burn, a skin graft from a cadaver may be used. It serves as a temporary covering over the wound, to prevent infection and loss of bodily fluid. It also shrinks the wound, and protects underlying tissues

_______________, horizontal depressions in the nail plate due to temporary interruption in nail growth, may be due to certain malnutrition or cancer chemotherapy drugs

Beau's lines

how do fingerprints form?

Genetics play a role in general patterns of fingerprints. Fingerprints form from ridges in the dermal papillae. Formation of fingerprints begins when a fetus presses the ridges against the walls of the uterus as it moves out. Individual variations, called papillary minutiae, develop as the fetus moves in its unique way.

What is the tissue response to inflammation?

Inflammation is a normal response to injury, stress or infection. Blood vessels in the injured area dilate, bringing in more blood, which contains oxygen, nutrients, and phagocytes. Increased blood vessel permeability brings more fluids to the area. The tissue also responds by increasing its metabolic activities, to heal the area faster.

besides body temperature regulation, what are some other functions of the skin?

It acts as a protective covering and a barrier against microorganisms. It also houses sensory receptors, plays a role in vitamin D production, produces melanin pigment to prevent against UV radiation, and helps to heal wounds

How is body heat produced?

It's produced by cellular metabolism as it breaks down food particles, particularly in the skeletal and cardiac muscle cells

Select three reasons why the ability to control body temperature declines with age

Loss of skeletal muscle mass reduces the ability to shiver. The capillary beds surrounding sweat glands and hair follicles shrink. The number of sweat glands in the skin decreases.

__________ is secreted into hair follicles through short ducts and helps keep the hairs and the skin soft, pliable, and waterproof. Acne can result from excess secretion

Sebum

A sweat gland consists of ______.

a tiny tube that originates as a ball-shaped coil in the dermis or the subcutaneous layer

___________ cells engulf invading microbes within the skin, process and display parts of the microbe on their cell membrane, and then migrate to lymphatic tissues to alert other immune cells, ultimately leading to the destruction of the invading microbes

dendritic

The boundary between the dermis and the epidermis is uneven, because epidermal ridges project inward and tapered projections, called _________, extend from the dermis into the spaces between the ridges.

dermal papillae

__________ increase the surface area where epidermal cells receive oxygen and nutrients from dermal capillaries

dermal papillae

As one ages, the skin produces less collagen and elastin. This causes thinning of what layer?

dermis

The __________ is composed entirely of stratified squamous epithelium, and therefore it lacks blood vessels

epidermis

The superficial outer layer, called the _________, is composed of stratified squamous epithelium

epidermis

When the body temperature rises above normal, the nervous system stimulates merocrine sweat glands to release sweat onto the surface of the skin. As this fluid evaporates, it carries heat away from the surface, cooling the skin. This process is called

evaporation

In large, open wounds, the healing process may be accompanied by the formation of ____________ that develop in the exposed tissues, each one consisting of a new branch of a blood vessel and a cluster of collagen-secreting fibroblasts that the vessel nourishes

granulations

The epithelial cells are nourished from dermal blood vessels in a projection of connective hair tissue called the ____________

hair papilla

The hair follicle also contains the ___________, which can extend from the skin surface into the dermis and sometimes into the subcutaneous layer.

hair root

dermal papillae are most abundant in the

hands and feet

How does the body lose excess heat?

heat loss occurs through vasodilation of dermal blood vessels, which sends more blood to the skin surface; heat is then released to the environment through the skin, by the process of radiation, conduction, convection, and evaporation of sweat

The age-related decrease in the number of blood vessels in the skin as well as in deeper regions accounts for which three changes?

impaired ability to regulate body temperature pale complexion common in older individuals dulling and hardening of nails

_______ is the normal response to injury or stress. Blood vessels dilate and become more permeable, allowing fluid to leak into damaged tissues.

inflammation

Where are the secretions of apocrine sweat glands released?

into hair follicles

__________ injections are administered into the skin

intradermal

a yellowish skin tone may indicate ________, which is a consequence of liver malfunction

jaundice

The scaly appearance of the skin of older individuals results from changes in the protein called ______, found within epidermal cells.

keratin

As the cells of the stratum basale divide and grow, the older epithelial cells, called _____________, are pushed away from the dermis to the skin's surface. The farther the cells move away from the dermal blood vessels, the poorer their nutrient supply becomes, and in time, they die

keratinocytes

dermal blood vessels supply oxygen and nutrients to all skin cells, except the ___________ in the strata above the stratum spinosum that are too far removed from this source

keratinocytes

one type of sensory receptor in the deeper dermis, ____________, responds to heavy pressure, whereas another type is in the upper dermis, _____________, senses light touch, and texture. Still other receptors (free nerve endings), extend into the epidermis and respond to temperature changes or to factors that can damage tissues

lamellated (Pacinian) corpuscles, tactile (Meissner's) corpuscles

______________ are scattered throughout the skin but are not on the palms or the soles

sebaceous glands

_________ provides skin color and absorbs ultraviolet radiation in the sunlight, which would otherwise cause mutations in the DNA of skin cells and other damaging effects

melanin

Specialized cells in the epidermis called ___________ produce the pigment melanin from the amino acid tyrosine in organelles called melanosomes

melanocytes

differences in skin color result from the differences in the amount of melanin produced by ____________, which is controlled by several genes

melanocytes

The most numerous sweat glands are the _____________, also known as eccrine sweat glands

merocrine sweat glands

The dermis has two layers: the superior layer is the _________, composed of areolar connective tissue. The deeper and thicker layer is the ________ composed of dense irregular connective tissue that consists of tough collagen fibers and elastic fibers in a gel-like ground substance

papillary layer, reticular layer

The primary means of body heat loss is _______, by which infrared heat rays escape from warmer surfaces to cooler surroundings. These rays radiate in all directions, much like those from the bulb of a heat lamp

radiation

A burn that destroys some epidermis as well as some underlying dermis is a deep-partial thickness (____________) burn. Fluid escapes from damaged dermal capillaries, accumulating beneath the outer layer of epidermal cells, forming blisters

second degree

The healing of what type of burn requires that healing be initiated by stem cells found within undamaged accessory structures?

second degree

The _________, the largest organ in the body by weight, and its various accessory structures (hair, nails, sensory receptors, arrector pili muscles, and glands) make up the integumentary system

skin

Signs of age in the accessory structures of the skin include which three changes?

slower replacement of hair decrease in melanin production slowed the growth of hair

In keratinization, the cytoplasm fills with strands of tough, fibrous, waterproof keratin proteins. As a result, many layers of tough, tightly packed accumulate in the outermost layer of the epidermis called the ____________. These dead cells are eventually shed.

stratum corneum

Scattered across the stratum basale are oval-shaped _____________, also called Merkel cells, that respond to light touch, and when pressed upon, release chemicals that stimulate the sensory nerve ending of the tactile disc

tactile cells

Each tactile cells corresponds with a sensory nerve ending, forming a _________ in the dermis

tactile disc

A burn that destroys the epidermis, dermis, and accessory structures of the skin is a full-thickness (__________) burn. The injured skin becomes dry and leathery and may vary in color from red to black to white

third degree