Chapter 5 Integumentary System

organs that make up the integumentary systemskin, nails, hair follicles, sebaceous glands, sweat glands, specialized nerve endings
SKINone of the largest organs in the body, is .5mm to 4.0 mm thick
epidermissuperficial region of skin
dermismiddle region of skin
hypodermissuperficial fascia- deepest region
skin layer
Epidermisepithelial tissue that attaches to dermis- keratinized stratified squamous epithelium. HAS NO BLOOD VESSELS (AVASCULAR)
cells of epidermiskeratinocytes, melanocytes, langerhans cells merkel cells (tactile cells)
keratinocytesproduce fibrous proteins, 90% of cells, connected by desmosomes, produced in stratum basale and pushed to surface, dead when they reach the surface 25-45 days from production to sloughing off FUNCTION: protective barrier
melanocytes10-25% of cells in lower epidermis,produce brown-black pigment called melanin, melanin is accumlated in membrane bound granules called melanosomes and transferred to nearby keratinocytes
merkel cellstouch receptors, only present in stratum basale, form a merkel disc for sensation of light touch
everyone has the same number of melanocytestrue
langerhans cellsimmune system cells which detect and present antigens to other immune system cells, macrophages that ingestantigens and activate immune system
5 layers of epidermisstratum corneum, stratum lucidum, stratum granulosm, stratum spinosum, stratum basale
most superficial layer, 20-30 layers of dead cells represented only by flat membrane sacs filled with keratin. Glycolipids in extracellular spacestratum corneum
three to five layers of flattened cells, organelles deteriorating, cytoplasm full of lamellated granules that release lipids and keratohyline granulesstratum granulosum
several layers of keratinocytes unified by desomoes, cells contain thick bundles of intermediate filaments made of pre-keratinstratum spinosum
deepest epidermal layer, one row of actively mitotic stem cells, some newly formed cells become part of the more superficial layersstratum basale
thick skin- bottoms of toes, soles, palms fingertips5 layers of skin
stratum basaleanchored to basement membrane, consists of single layer of mostly stem cells undergoing mitosis to become keratinocytes, a few melanocytes that create skin pigment and occasionally merkel cells
Stratum Spinosum (prickly layer)7-10 layers of cells, mostly keratinocytes with a few langerhans cells and some melanin granules
stratum granulosumthin consists of 3-5 cell layers in which drastic changes in keratinocyte appearance occurs (cells flatten) keratohyaline -granules- precursors to keratin, lamellated granules- waterproofing glycolipids
cells in stratum granulsum die becausethey are getting too far away from blood vessels in dermis,, they are programmed to die
stratum lucidumonly found in thick skin of palms, soles, fingerips, and bottoms of toes- 3-5 layers of flat clear dead keratinocytes
stratum corneumhorny layer, 20-30 layers of dead keratinocytes, FUNCTIONS protects from abrasion, penetration, waterproofs,
contains flycolipid between cells to waterproof skinstratum corneum
serves as a physical barrier again light, heat, microorganisms, water and chemicalsstartum corneum
callusthickening of epidermis due to frequent friction or abrasion
epidermal growth factorprotein hormone which stimulates stratum basale cells to undergo mitosis
found in saliva of many mammals and produced by other cellsepidermal growth factor
Dermissecond major skin region containing strong flexible connective tissue
cell types include fibroblasts, macrophages and occasionally mast cellsdermis
rich supply of blood vessels and nerves, contains glands and hair folliclesdermis
Papillary layer (dermis)superfical layer that makes up 20% of dermis, areolar connective tissue with collagen and elastic fibers and blood vessels
composed of small fingerlike projections called dermal papillae which push up into epidermispapillary layer
dermal papillae (papillary layer of dermis)contains capillary loops, meissnesr’s corpuscles(touch receptors) and free nerve endings for pain. FUNCTION: to increase surface area of contract between epidermis and dermis, to increase diffusion and bettwe resistance to abrasion
fingertipscaused by dermal ridges and dermal papillae resulting in erpidermal ridges FUNCTION to increase friction for gripping
reticular layer (deep layer of dermis)80 % of dermis, dense irregular connection tissue with thich collagen and coarse elastic fibers
collagen fibers in the layer add strendth and resiliency to the skin, elastic fibers provide stretch-recoil propertiesreticular layer
contains hair follicles, nerves, sebaceous glands, sweat glands, pacinian corpuscles and blood vesselsreticular layer
cleavage or tension linesskin markings that seperations between bundles of collagen that run parallel to skin surface
flexure linesskin markings that are dermal folds that occue at or near joints where the dermis is tightly secured to deeper structures- palms, wrists, fingers, soles and toes
stretch marks (striae)result from dermal tearing, casused by severe strectching -homeostatic imbalance
blistersresult from tearing of weak areolar CT of papillary layer
Subcutaneous tissue (hypodermis and superficial fascia)composed of adipose tissue, and areolar connective tissue, contains cold senestive nerve endings
pigments that contribute to skin colormelanin, carotene, hemoglobin
melanindifferent forms that range in color, produce melanocytes located in the stratum basale of the epidermis
accumulates in membrane-bound granules called melanosomes that are moved to ends of melanocytes processesmelanin
melanosomes are taken up by basal keratinocytestrue
local accumulations of melanin results in freckles, moles, and age spotstrue
caroteneyellow to orange pigment found in carrots, egg yolks and tomatoes, localizes in the stratum corneul and adipse tissue, most obvious in palms and soles
high consumption of carotene-containing foods gives skin a yellow huetrue
yellowish skin of some asian people is sue to variants of carotenefalse- melanin is the cause
hemoglobina red pigment in red blood cells, skin is translucent when little melanin and carotene are present (fair people)
red-pink color of blood in dermal capillaries shows through skin as pinkish huetrue-hemoglobin
cyanosisblood and skin of caucasians appear blue when hemoglobin is poorly oxagentaed- during heart failure, sever respiratory disorders , if a baby does not breath shortly after birth
erythemaredness of skin, fever, hyertension, inflammation, allergy, blushing
palor or blanchingpale skin, anemia, low blood pressure, during fear, anger and certain types of emotional stress
jaundiceabnormal yellowing of the skin caused by a liver disorder(yellow bile pigments)
bronzingbronzing of skin sign of addisons disease
bruisesblood from ruptured capillaries below skin which clotted beneath the skin
hematomasclotted blood masses
derivatives of the epidermissweat glands, sebaceous glands, hair and hair follicles, nails
sweat glands3-4 million per person, 2 types: eccrine and apocrine
eccrine sweat glandsmost common type, simple, coiled tubular gland that carries sweat through dermis to surface pores
found everywhere EXCEPT lips, nail beds, nipples, external genitalia ear drumseccrine sweat glands
sweathypotonic to plasma, 99% water,some salts, vitamin C FUNCTION: cools body and eliminates waste
apocrine sweat glandssecretes by exocytosis, found in axilla and pubic region, ducts connect to hair follicles so hair conducts secretion into air
bacteria decompose of fat and proteins resulting in odor; stimulated by emotional stress and sexual excitementapocrine sweat glands
mammary glandsweat glands specialized to secret milk
ceruminous glandsfound in skin of external ear canal to secrete ear wax
sebaceous glandswidely distributed except on the palmer and planter surfaces of hands and feet,
develops from hair follicles, secretes oil onto hairs in hair follicles, micute of fats, cholesterol, proteins and saltssebaceous glands
Functions: softens hair and skin, reduces water evaporation, bacterialsebaceous glands
hairfunctions” protects from sunlight, heat loss, particles and insects
hair is distributed over the enitre skin surface expect palms, soles, lips, nipples and portions of external genitaliatrue
hair is filamentous strands composed ofdead, hard keratinized cells produced by hair follicles
hair shaftabove epidermis
hair rootin epidermis and dermishollow tube that holds hair
medullacentral core of large cells and air spaces
cortexthickest layer,keratinized pigmented flattened cells- surrounds medulla
cuticle of hairsingle outer layer of keratinized cells that overlap each other- surrounds cortex
hair follicleextends from epidermal surface into dermis- lining of hair shaft
connective tissue root sheathdermis-blue exterior area on outer follicle wall
glassy membranethickened basement membrane- dark blue membrane between CT root sneath and external epithelial root sheath
external epithelial root sheathtissue after the glassy membrane
internal root sheathtissue after external epithelial root sheath before cuticle
hair bulbexpanded deep end, enlarged base of follicle-bottom of follicle directly under root
hair papilla of hair bulbconnective tissue with many blood vessels
hair matrix of hair bulbring of actively didving cells
sebaceous glands are with each hairtrue
hair follicle receptorsensory nerve endings around each hair bulb, stimulated by bending a hair
arrector pili musclesmooth muscle that runs from connective tissue root sheath to suferficial dermis- contracts hair vertically
cause goose bumps, decreases heat loss by increasing the dead air space above skin, induced by stimuliarrector pili muscle
hair growth2 cycles growth phase and resting phase
lasts 6-10 years in scalp, 3-4 months in eyebrowsgrowth phase
last 1-3 monthsresting phase
velluspale, fine body hair of children and adult femals
terminalcoarse, long hair of eyebrows, scalp, axillary and pubic regions
hirsutismexcessive hairiness in women due to abnormal secretion of androgens
hair pigmentsmelanins in medulla and cortex
dark hairtrue melanin
blonde and red hairmelanin variants with iron and sulfur
gray/white hairdecreased melanain production, increased air bubble in shaft
alopeciahair thining in both sexes after age of 40
frank(true) baldnessgenetically determind and sex-influenced condition
nailscalelike modification of epidermis on distal dorsal surface of fingers and toes
nail bodypink due to blood underlying capillaries
lunulawhite cresent shape at bottom of nail
free edgewhite edge of nail
nail rootanchored in skin
cuticlethick stratum corneum
Chemical Barrierlow pH secretions(acid mantle) and defensisn retard bacterial activity
melanin provides a chemical pigment to prevent UV damage to the viable skin cellstrue
physical/mechanical barrierskeratin and glycolipids block most water and water-soluble substances
The most abundant cells of the epidermis.Keratinocytes
The protein found in the epidermis that is responsible for toughening the skinKeratin
Cells plus a disc-like sensory nerve ending that functions as a sensory receptor for touchMerkel disc
Skin macrophages that help activate the immune systemEpidermal dendritic cells
Cell remnants of the stratum corneumCornified keratinocytes
The layer of the epidermis where the cells are considered protective but nonviableStratum corneum
The glands that serve an important function in thermoregulationSudoriferous glands
The layer that contains the mitotic viable cells of the epidermisStratum basale
Hair that lacks pigment and is often called “immature hair.”Vellus
May indicate embarrassment, fever, hypertension, inflammation, or allergy.Erythemia
May indicate fear, anger, anemia, or low blood pressurePallor
Usually indicates a liver disorderJaundice
Appearance of a permanent tan; bronzing.addisons disease
A bluish color in light-skinned individualsCyanosis
The apocrine sweat glands are fairly unimportant in thermoregulationTrue
Skin surface markings that reflect points of tight dermal attachment to underlying tissues are
called epidermal ridges
false
The dense fibrous connective tissue portion of the skin is located in the reticular region of the
dermis
true
The outermost sheath of a hair follicle is the connective tissue root sheathtrue
The protein found in large amounts in the outermost layer of epidermal cells is collagen.false
Joe just burned himself on a hot pot. A blister forms and the burn is painful. Joe’s burn would
best be described as a third-degree burn
false
Destruction of the matrix of the hair bulb would result in its inability to produce oilfalse
The hyponychium is commonly called the cuticlefalse
The reason that the nail bed appears pink is the presence of a large number of melanocytes in
the underlying dermis
false
During the resting phase of hair growth, the matrix is inactive and the follicle atrophies.true
The most dangerous skin cancer is cancer of the melanocytes.true
The skin is not able to receive stimuli because the cells of the epidermis are not living and therefore there are no sensory receptors in the skinfalse
The dermis is rich in blood vessels and nerve fibers.true
The hypodermis is composed of adipose and dense connective tissuefalse
A physician is often able to detect homeostatic imbalances in the body by observing changes in the skin colortrue
When an individual is exposed to extremely low air temperatures, the dermal blood vessels will dilate so that blood and heat will be dissipated.false
Regardless of race, all human beings have about the same number of melanocytestrue
Ceruminous glands are modified merocrine glandsfalse
The stratum corneum (outermost layer of skin) is a zone of approximately four layers of viable cells that are able to synthesize proteins that keep the outer layer of skin smooth and softfalse
The pinkish hue of individuals with fair skin is the result of the crimson color of oxygenated hemoglobin (contained in red blood cells) circulating in the dermal capillaries and reflecting through the epidermis.true
Hair growth and density are influenced by hormones, nutrition, and, in some cases, lifestyletrue
When a patient is said to have “third-degree burns,” this indicates that the patient has burns that cover approximately one-third of the body.false
Sweat glands continuously produce small amounts of sweat, even in cooler temperaturestrue
Melanomas are rare but must be removed quickly to prevent them from metastasizingtrue
________ is an inherited condition that affects the heme pathway; it leaves the skin scarred and gums degenerated, and may have led to the folklore about vampires.Porphyria
A needle would pierce the epidermal layers of the forearm in which ordercorneum, granulosum, spinosum, basale
The major regions of a hair shaft include all of the following except ________.external root sheath
Acne is a disorder associated with ________.sebaceous glands
The dermis ________.has 2 layers
Which muscles attached to the hair follicles cause goose bumpsarrector pili
If a splinter penetrated the skin into the second epidermal layer of the sole of the foot, which cells would be damaged?lucidum
Which of the following cutaneous receptors is specialized for the reception of touch or light pressure?Meissner’s corpuscles
Which of the following is a skin sensory receptor for touch?Meissner’s corpuscle
Which statement correctly explains why hair appears the way it doesKinky hair has flat, ribbonlike hair shafts
Sudoriferous glands vary in distribution over the surface of the body. Which of the following is correct?Ceruminous glands secrete cerumen, which is thought to deter insects
Although the integument is a covering, it is by no means simple, and some of its functions include ________.resident macrophage-like cells whose function is to ingest antigenic invaders and present
them to the immune system
The function of the root hair plexus is to ________.allow the hair to assist in touch sensation
Vernix caseosa is a ________.whitish material produced by fetal sebaceous glands
The ________ gland is a modified sudoriferous gland that secretes waxceruminous
Nutrients reach the surface of the skin (epidermis) through the process of ________.diffusing through the tissue fluid from blood vessels in the dermis
The reason the hypodermis acts as a shock absorber is that ________.the major part of its makeup is adipose, which serves as an effective shock absorber
Which type of skin cancer appears as a scaly reddened papule and tends to grow rapidly and metastasizeSquamous cell carcinoma
Keratinocytes are an important epidermal cell because they ________.produce a fibrous protein that gives the skin much of its protective properties
Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment
layer
The epidermis consists of five layers of cells, each layer with a distinct role to play in the health, well-being, and functioning of the skin. Which of the following layers is responsible for
cell division and replacement?
stratum basale
The integumentary system is protected by the action of cells that arise from bone marrow and
migrate to the epidermis. Which of the following cells serve this function?
macrophages called epidermal dendritic cells
Water loss through the epidermis could cause a serious threat to health and well-being. Which of the following protects us against excessive water loss through the skin?Lamellated granules of the cells of the stratum granulosum, a glycolipid that is secreted into
extracellular spaces
The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis?fibroblasts, macrophages, and mast cells
The dermis has two major layers; which of the following constitutes 80% of the dermis and is responsible for the tension lines in the skin?the reticular layer
Despite its apparent durability, the dermis is subject to tearing. How might a person know that the dermis has been stretched and/or torn?The appearance of visible, silvery-white scars is an indication of stretching of the dermis
The papillary layer of the dermis is connective tissue heavily invested with blood vessels. The superficial surface has structures called:dermal papillae.
The design of a person’s epidermal ridges is determined by the manner in which the papillae rest upon the dermal ridges to produce the specific pattern known as handprints, footprints, and
fingerprints. Which of the following statements is true regarding these prints or ridges?
They are genetically determined, therefore unique to each person
Which of the following statements indicates the way in which the body’s natural defenses protect the skin from the effects of UV damage?Prolonged exposure to the sun induces melanin dispersion, which in turn acts as a natural
sunscreen.
Changes in the color of skin are often an indication of a homeostatic imbalance. Which of the following changes would suggest that a patient is suffering from Addison’s disease?The skin takes on a bronze or metallic appearance
An epidermal dendritic cell is a specialized ________.phagocytic cell
What are the most important factors influencing hair growth?nutrition and hormones
Which of the following statements best describes what fingernails actually areFingernails are a modification of the epidermis
Sudoriferous (sweat) glands are categorized as two distinct types. Which of the following are the two types of sweat glands?eccrine and apocrine
The composition of the secretions of the eccrine glands is ________.99% water, sodium chloride, trace amounts of wastes, and vitamin C
Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in hermoregulation. Where would we find these glands in the human body?in the palms of the hands and soles of the feet
The sebaceous glands are simple alveolar glands that secrete a substance known as sebum. The secretion of sebum is stimulated ________.by hormones, especially androgens
In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the skin?It converts modified epidermal cholesterol to a vitamin D precursor important to calcium
metabolism.
Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage associated with such dangerous
fluid loss
by using the “rule of nines”
What is the first threat to life from a massive third-degree burncatastrophic fluid loss
Male pattern baldness has a genetic switch that turns on in response to ________.male hormones
Eyebrow hairs are always shorter than hairs on your head because ________.eyebrow follicles are only active for a few months
Cradle cap in infants is called ________.seborrhea
The white crescent portion of the nail is called the ________.lunula
The layer of the epidermis immediately under the stratum lucidum in thick skin is the stratumgranulosum
The ________ are the small muscles located in the dermis that cause goose bumps.arrector pili
A summertime golden bronze tan may not be a tan at all; especially if the skin appears almost
metallic bronze, it may be the result of ________ disease.
addisons
The coarse hair of the eyebrows and scalp is called ________ hair.terminal
________ burns injure the epidermis and the upper regions of the dermissecond-degree burns
________ are pigment-producing cells in the epidermisMelanocytes
The only place you will find stratum ________ is in the skin that covers the palms, fingertips,
and soles of the feet.
lucidum
The dermis is composed of the reticular and ________ layerspapillary
Name the four kinds of sudoriferous glandseccrine
2. apocrine
3. ceruminous
4. mammary