A&P Ch6 Mcgraw Hill Integumentary system

dermal papillae

the upward projections of the dermis at the dermis-epidermis boundary

integumentary system consists of?

Consists of the skin (dermis & epidermis), mucous membranes, hair, nail, cutaneous glands

How visible is the integumentary system?

it is the most visible

What is dermatology?

is the branch of medicine specializing in the care and treatment of the skin

What should a general physician examination include?

-inspection of the hair, skin, and nails.

-Appearance can provide clues to ones overall health and other disordered such as liver cancer, anemia, and heart failure.

Things that can damage the skin? (most vulnerable of our organs)

-radiation, trauma, infection, injurious chemicals

-it needs and recieves more medical attention than any other organ system

T/F: is the skin (integument) the largest and heaviest organ?

TRUE

How much area does the skin cover?

an area of 22 sq ft (an average adult). It is the largest organ of the body

How much body weigh does skin account for?

15%

how many layers does the skin consist of?

Two : epidermis and dermis

What is the epidermis?

-Outer layer of skin

-stratified squamous epithelium

what is the dermis?

Inner deeper layer of skin

The acid ____ is the protective film that gives skin its slight acidity?

mantle

Few infectious organisms can penetrate the intact skin because of what?

the acid mantle

stratum basale

stem cells divide and new karatinocytes are produced

stratum spinosum

mitosis ceases. Keratinocytes are pushed upward as new cells are added below them

startum granulosum

keratin filaments are bound together to form waterproof bundles. Keratinocytes die.

stratum corneum

dead keratinocytes exfoliate from the skin surface

the dermis consists of connective tissue, with ____ as the most common fiber type within the layer.

collagen

Where is the hypodermis located?

Immediately deep to the dermis is the hypodermis, or subcutaneous tissue (primarily adipose tissue).

What compound is the primary determinate of skin color?

melanin

What is melanin produced by?

melanocytes but accumulates in the keratinocytes of the stratum basale and stratum spinosum

there are two forms of melanin called what?

Eumelanin: brownish black

Pheomelanin: reddish yellow

people with different skin colors have the same # of melanocytes. What is different in dark skin?

in dark skin, the melanocytes produce greater quantities of melanin

What is the keratinocytes like in dark skin and light skin?

-dark skin in the keratinocytes are more spread out and the melanin breaks down more slowly

-light skin is clumped near the keratinocyte so less color shows through and it breaks down more rapidly

Flexion creases, friction ridges and patches of pigmentation are all examples of:

skin markings

friction ridges are responsible for what?

creating fingertips

events of keratinocyte in order

-stem cells divide to produce new keratinocytes

- mitosis ceases as epidermal cells are pushed upward

- keratinocytes flatten and produce waterproof bundles of keratin filaments

- keratinocytes die

- dead keratinocytes flake off the surface of the skin as dander

in which areas of the body is the dermis the thickest?

palms and soles

what is below the dermis?

hypodermis (not apart of the skin)

What does the skin do with water?

it makes sure to keep outside water (pool) out and drinking water in

thermoregulation

Process of maintaining an internal temperature within a tolerable range.

The epidermis is composed of five cell types:

stem cells, keratinocytes, melanocytes, tactile cells, and dendritic cells

What are tactile cells?

touch receptors

What are dendritic cells?

immune cells

what is hair known as?

Singular - pilus

plural - pili

what is Lanugo?

fine downy hair of newborn infant

what is vellus hair?

2/3s of women hair, 1/10 of men hair, an dall the hair of children except for eyebrows, eyelashes, and scalp

what is terminal hair?

-longer, coarser, and more pigmented.

-it forms the eyebrows, eyelashes, and covers scalp

-after puberty: pubic hair, male facial hairs, and some hair on trunk of limbs

hair above the skin is ___ and beneath surface is ___, and ends with a ___

shaft; root; bulb

Thin skin found where?

eyelids,

cells in the epidermis are nourished by blood vessels located where?

in the dermis

epidermal layers in order (most superficial to deepest)

stratum corneum, stratum lucidum, stratum granulosum, stratun spinosum, and stratum basale

hair follicles and nail roots are embedded in what layer of skin?

dermis

what is the effect of exposure to UV rays on skin?

melanin synthesis (darkens skin)

T/F: hemoglobin and carotene both influence skin coloration

True: hemoglobin gives pink cast and carotene a yellow cast

birth marks, aka ____, are patches of skin discolored by benign tumors of blood capillaries

hemangiomas

T/F: the epidermis is highly vascular

false

apocrine sweat glands occur where?

groin, anal region, axilla, and areola, mature males, and beard area

Where are apocrine duct glands found?

nearby hair follicales instead of skin surface

what type of secretion do apocrine glands use?

exocytosis

what kind of stimulation impacts apocrine glands to sweat?

stress and sexual stimulation

where are merocrine (eccrine) sweat glands?

widely distributed over the entire body, expecially on the palms, soles, and forehead

what is the primary function of the merocrine glands?

to cool the body

what is true about apocrine sweat glands?

- not active until puberty

- occur in groin, anal region, axilla, areola, and bear area

-produce sweat that contains fatty acids

which type of sweat gland has a duct that opens by way of pore on skin surface?

merocrine sweat gland

Describe merocrine glands?

simple tubular gland with a twisted coil in the dermis or hypodermis, and an undulating or coiled duct leading to a sweat pore on the skin surface.

oil producing glands associated with hair follicles are called ____ glands

sebaceous

What do ceruminous glands secrete?

they waterproof the ear canal, and coats the guards of the hair

all sweat glands (apocrine and merocrine) release their secretion via which of the processes?

exocytosis

which clinical term is used to describe disagreeable body odor?

bromhidrosis

____ cells found in aprocrine and merocrine sweat glands have contractile properties similar to smooth muscle

myoepithelial

which describes the composition of sweat?

acidic solution containing urea, potassium, sodium chloride, and ammonia

the process by which perspiration evaporates as fast as it is produced is called what?

insensible perspiration

which process produces large amounts of sweat, wetting the skin?

diaphoresis

sebaceous glands produce a secretion that can be described as what?

oily

____ glands are flasked shaped, with short ducts that usually open into a hair follicle and directly onto skin?

sebaceous

sweat glands that have a relatively narrow lumen and a duct that opens by way of pore on the skin surface are called ____ sweat glands

merocrine

____ glands secrete a substance that combines with sebum to keep the eardrum protected and prevent foreign particles from entering the canal

ceruminous

first degree burn?

only the dermis is involved. there is redness, edema, and pain

second degree burn

the epidermis and part of the dermis is involved. There are usually blisters

third degree burns

the epidermis, entire dermis, and often some deeper tissues are involved. this type of burn often require skin graft

The skin is essential in sensing:

injury, touch, temperature

T/F: epidermal tissues regenerate more quickly than many other tissues

true

the epidermal water barrier is a layer of lipids located between which two layers?

stratum spinosum and stratum granulosum

which term refers to the shedding of skin cells?

exfoliation