Anatomy Test 2- Ch 5

structures of the integumentary sytem

• skin

• hair

• nails

• glands

functions of the integumentary system

• protection

• sensation

• temperature

• vitamin D production

• excretion

integumentary

protects against UV light, microogranisms, water loss is the protecton of the ________ system

function

sensation _______ of the integumentary system includes sensory receptors for heat, cold, touch, pressure, and pain

temperature regulation in integumentary system

modulation of blood flows through the skin and activity of sweat glands (keyword: in)

vitamin D

________ production from a molecule made in the skin when exposed to UV light

excretion

• function of integumentary system

• small amounts of waste products eliminated

epidermis

superficial layer of stratified epithelial tissue

• protection and reduces water loss

dermis

deep layer of CT

• structural strength

subcutaneous tissue

• not part of the skin

• loose CT that connects skin to underlying structures

epidermis layer

• avascular; nourished by diffusion from capillaries of the papillary layer of the dermis

• composed of epithelial cells arranged into layers or strata

• separated from dermis by basement membrane

epidermal cells

• keratinocyte

• melanocytes

• langerhan (epidermaldendric) cells

• merkel (tactile) cells

keratinocytes

• type of epidermal cell

• most cells. produce keratin for strength

• kills and toughens cell

melanocytes

• epidermal cell

• contribute to skin color

• melanin produced by these cells is them transferred to keratinocytes

• same number in all people

langerhans cells

• epidermal cell

• part of the immune system

merkel cells

• epidermal cell

• detect light touch and superficial pressure

keratinization

as cells move outward through the layers, they fill with keratin, die, and serve as a layer that resists abrasions and forms permeability layer

Layers of the epidermis from deep to superficial

stratum basale (germinativum)

stratum spinosum

stratum granulosum

stratum lucidum

stratum coreum

stratum basale (germinativum)

• deepest portion of epidermis

• single layer of cuboidal or columnar cells with hemidesmosomes at the bottom

• high mitotic activity; keratinocyte stem cells undergo mitosis every 19 days; one daughter cell remains in the ______ to divide again, while the other daughter cell is pushed up to the surface and becomes keratinized

• desmosomes hold keratinocytes together and provide structural strength

basale

it takes 40 to 56 days to move from the stratum _____ to the surface and being sloughed off

stratum spinosum

• spiny layer

• eight to ten layers of many-sided cells that flatten as they are pushed upward

• contain new desmosomes, lipid-filled lamellar bodies, and additional keratin fibers

stratum granulosum

• 2-5 layers of flattened, diamond-shaped cells

• contain protein granules of keratohyalin (toxic) that accumulates in the cyctoplasm

• lamellar bodied move to the plasma membrane and release their lipid contents into the extracellular space

• in superficial layers, nucleus; and other organelles degenerate and cell die

• the keratin fibers and keratohyalin granules do not degenretage

• in here cells are starting to be destroyed

stratum lucidum

• tin, clear zone of dead keratinocytes with indistinct boundaries

• found only in palms and soles (thick skin)

stratum corneum

• dead keratin filled cells; the keratin makes the skin tough

• most superficial and consists of 25 or more layers of dead, overlapping squamous cells joined by desmosomes called cornified cells

• cell remnants have a soft protein envelope of keratin, a mixture of keratin fibers, and keratohyalin

cornified cells

• dead, overlapping squamous cells joined by desmosomes

• flat, dead cells filled with a tough protective protein called keratin

thick skin

• designation refers only to the epidermis

• has all 5 epithelial strata

• found in areas subject to pressure or friction

  • palms of hands, fingerprints, soles of feet

• fingerprints and footprints, papillae of underlying dermis in parallel rows

spinosum

fingerprints and footprints; the whorls of our fingers are formed due to the stratum _____

thin skin

• composed of 4 epithelial strata

  • no stratum lucidum

• more flexible than the other skin

• covers rest of the body

• hair grows here

callus

• increase in number of layers in stratum corneum; tough area where skin cells did not shed off

corn

as callus is a spot on the body where there is an increased number of layers in stratum corneum (layers didn’t shed off) and when this occurs over a bondy prominence, a ___ forms

3 factors that determine skin color

1. pigments in the skin

2. blood circulation through the skin

3. thickness of stratum corneum

pigments

1. melanin

   1. melanocytes and albinism are associated with it

2. carotene

melanin

provides for protection against UV light

group of chemicals derived from amino acid tyrosine

colored brown to black, may be yellowish or reddish

melanocytes

• processes extend between keratinocytes

• deposit melanosomes (specialized, membrane-bound organelles that synthesize, store and transport melanin)

albinism

deficiency or absense of pigment

production determined by genetics, hormones, exposure to light

carotene

• vitamin A

• yellow pigment from vegetables

• accumulates in stratum corneum, adipose cells of dermis, and in the subcutaneous tissue

racial

_____ variations in skin color due to:

1. types of melanin produced

2. amount of melanin produced

3. size of melanosomes (specialized, membrane-bound organelles that synthesize, store and transport melanin)

4. number of melanosomes

5. distribution of melanosomes

estrogen

certain hormones such as, ____ and MSH (melanin stimulus hormone), can increase melanin production during pregancy

ex: the dark line that you get from your naval to pubic

reddish

blood circulation through the skin imparts _____ hue and increases during blushing, anger, and inflammation

cyanosis

• blue color caused by decrease in blood oxygen content

• if patient comes in with blue skin, put oxygen on them before you grab doctor

• only time you wont, which will never happen is someone comes in with CO2 poisoning but it won’t happen because they wont be able to walk to hospital

erythema

red color caused by increased blood flow

corneum

thickness of stratum ___ impacts color

• thicker areas can be yellowish

dermis

pigments and other substances in the ____ or subcutaneous tissue may impart a bluish color to the skin; the deeper the bluer

skin cancer

• most common type of cancer

• most result from damage from UV radiation that damages the DNA in epidermal cells

melanin

the amount of ___ affects the likelihood of developing skin cancer

fair skinned people are at a greater risk than dark skinned people

3 major types of skin cancer

1. basal cell carcinoma

2. squamous cell carcinoma

3. melanoma

basal cell carcinoma

• most common type of skin cancer

• cells of stratum basale

• varied appearance

• cured by removal or destruction

squamous cell carcinoma

• cells of stratum spinosum

• varied appearance; may bleed

• most cases cured by removal or destruction

melanoma

• most deadly form of skin cancer

• ABCDE rule for signs of _____

ABCDE rule for signs of melanoma

1. A- asymmetry

2. B- border irregularity

3. C- color not uniform

4. D- diameter greater than 6 mm

5. E- evolving or changing

dermis

• gives structural stength

• connective tissue with many fibers (collagen, elastic, and reticular), fibroblasts, macrophages, and adipocytes

• contains nerves, blood vessels, hair follicles, smooth muscles, glands, and lymphatic vessels

• sensory functions: pain, itch, tickle, temperature, touch, pressure, 2-point discrimination

• two layers: paillary and reticular and they vary in thickness

papillary layer

• superficial layer of the dermis

• areolar with lots of elastic fibers, dermal papillae, and capillary beds

• friction ridges form fingerprints, whorls of ridges

• touch receptors (meissner (superficial touch), pacinian (deep pressure), and ruffini (continuous touch)), free nerve endings sensing pain

reticular layer

• deep, dense irregular CT of collagen and elastic fibers

• also contains some adipose tissue, hair follicles, nerves, oil glands, ducts of sweat glands, and heat sensors

cleavage (tension) lines

• elastic and collagen fibers oriented in some directions more than in others

• important in surgery

  • if incision is parallel to lines, there is less gapping, faster healing, less scar tissue

• if skin is overstretched, stretch marks occue

subcutaneous tissue

deep to skin

also called hypodermis

consists of loose CT with collagen and elastic fibers

types of cells in subcutaneous tissue

1. fibroblasts- creates things

2. adipose cells- contains about ½ of body’s adipose tissue

3. macrophages- destroy things

function of subcutaneous layer

1. energy source

2. insulation

3. padding

intradermal injection

• ID

• into the dermis; skin taut and needle at a shallow angle

• ex: allergy shot

subcutaneous injection

• S

• into subcutaneous layer

• pinch the skin to get it

• short needle

intramuscular injection

• IM

• long needles perpendicular to skin (straight w no angle)

• ex: vaccines

hair

found everywhere on human body except palms, soles, lips, nipples, part of the external genitalia, and distal segments of fingers and toes

ages

hair structure and coloration changes as a person ____

laguno

delicate, unpigmented hair of the fetus

terminal hair

long, coarse, pigmented hair of the scalp, eyelids, eyebrows, and with puberty (axilla, pubic, and face)

vellus hair

fine, short hair of the rest of the body

not on the scalp, eyelids or eyebrows, axilla, pubic, or face

hair shaft

protrudes above skin surface

hair root

located below surface; base of root is the hair bulb

medulla

central axis

in the middle

the hair root is at the base of this

cortex

forms bulk of hair

center section

cuticle

forms the hair surface

the part of the hair you can visibly see

hair bulb

expanded base of the root

the white bulb that you see when you pull a strand of hair out

• internal matrix is source of hair

• dermis projects into the ____ as hair papilla, which is the blood supply

hair papilla

• also known as demal papilla

• serves as a blood supply

• a small, roudned structure at the base of the hair follicle that supplies blood, nutrients, and vital signals to control hair growth and regeneration

hair growth

growth and resting stages are cyclic

has a growth stage and a resting stage

growth stage of hair

cells added at the base and hair elongates

resting stage for hair

follicle shortens and holds hair into place

the hair will rest, then it falls out of the follicle (the tiny, tube-like structure of pocket in skin that surrounds the root and lower part of a hair strand)

new hair begins

• hair can only grow so long in people before it reaches its growing limit. some till butt, other to under breasts

permanent hair loss

pattern baldness (common, heredity condition that causes progressive hair loss and thining in a predictable, defined pattern) is the most common cause of _____

alopecia areata

_____ spot baldness most likely due to an autoimmune response

hair color

____ is caused by varying amounts and types of melanin.

• melanin can be black-brown and red. color is controlled by several genes

arrector pili

• type of smooth muscle

• extends from the dermal root sheath of the follicle to the papillary layer of the dermis

• muscle contraction causes hair to “stand on end”

• skin pushed up by movement of hair follicle to produce “goose bumps”

sebaceous glands

• holocrine (death of sencretory cells; whole cell dies to go in gland)

• sebum= oily secretion

• the sebum prevents drying and inhibits some bacteria

• most empty into hair follicle

  • exceptions: lips, meibomian glands of eyelids, genetalia

sweat (sudoriferous) glands

• two types: apocrine and merocrine

• apocrine may secrete in a merocrine or a holocrine fashion

eccrine (merocrine) glands

• type of sweat gland

• most common; numerous in palms and soles

• simple coiled tubular glands

• open directly onto the surface of the skin, and they each have their own pores

• coiled part of the dermis with the duct exiting through epidermis

• produce sweat (isotonic fluid)

• contain mostly water and some waste

• important role in body temperature regulation

apocrine glands

• type of sweat gland

• smell like and ape

• active in puberty

• simple coiled tubular glands

• usually open into hair follicles superficial to opening of a sebaceous gland

• secretion: organic components are odorless but bacteria is drawn to them so they become odiferousfound in axillae, genitalia (external labia, scrotium), around anus

• does not help in temperature regulation

ceruminous gland

modified eccrine sweat glands in the external auditory canal

• earwax (cerumen): composed of a combination of sebum and secretion from ceruminous

• function- earwax and the ear hairs together can prevent dirt and insects from entry

mammary glands

modified apocrine sweat glands that produce milk

nail structure

thin plate of layers of dead stratum corneum cells with hard keratin

nail body

stratum corneum

visible portion of the nail

eponychium (cuticle)

• the corneum superficial to the nail body

hyponychium

corneum beneath the free edge of the nail

matrix and nail bed

cells that give rise to the nail

nail _____ is the active tissue at the base of the nail that creates new cells to form the nail body

_______ is the skin directly under the nail body that provides support and adhesion

nail root

covered by skin; extends from the nail matrix

• located under the skin at the base of the nail where the new nail growth begins

lunula

small part of the nail matrix seen through the nail body as whitish, crescent-shaped area at the base of the bail

nail growth

• the nail matrix and bed are composed of epithelium tissue with a stratum basale that gives rise to the cells that form the nail

• grow continuously, unlike hair

• fingernails grow on.5 to 1.2 mm/day; faster than toenails

protection of the integumentary system

• against abrasians, sloughing off bacteria as desquamation (peeling of outer layer) occurs

• against microorganisms and foreign objects. Glandular secretions bacteriostatic and skin contains cells of the immune system

• melanin against UV radiation

• hair on head is an insulator and ______ against light and abrasion. Eyebrows keep sweat out of eyes; eyelashes protect eye from foreign objects. Hair in nose and ear against dust and bugs

• nails ___ ends of digits, self defense

• acts as a barrier to diffusion of water

sensation of integumentary system

sensory receptiors: pressure, temperature, pain, heat, cold, touch, movement of hairs

temperature regulation of integumentary system

sweating and regulation

• sweat causes evaporative cooling

• arterioles in the dermis change diameter as temoerature changes. more or less blood flows through the dermis

• keyword: of

heat exchange in the skin

1. body dilates your blood vessels so they get closer to the skin surface to absorb some of the heat

2. when evaporation cooling occurs, it takes heat from the blood vessels and as the blood continues to pump it is now cooler

-closer to the surface= cooling from the sweat on skin

deeper= heat preservation

vitamin D production

• begins in the skin

• aids in Ca2+ absorption

• ____ and calcium absorb each other, so take these pills together

calcitriol

vitamin D (_____): hormone

• it regulates how much calcium and phosphate we take in, controls how much is released and does it by affecting the amount of calcium kidneys secrete

cholecalciferol

7-dehydrocholesterol converts to cholecalciferol when exposed to UV light, which forms calcitriol (Vitamin D) when it is released into the blood and modified by the kidneys and liver