Bootcamp.com - Integumentary System

what are the key components of the integumentary system?

skin, hair, nails, glands, and nerves

from superficial to deep, the three distinct layers are ______, ______, ______

epidermis (epi = above), dermis, and hypodermis

is the skin composed of the hypodermis?

no, the "skin" is only composed of the epidermis and dermis

the epidermis is the most _____ layer of the skin, and it is thin and avascular

superficial

does the epidermis contain blood vessels?

no, the epidermis is avascular, meaning it does not contain blood vessels!

the _____ protects us from dehydration, UV radiation, and pathogens

epidermis

the epidermis receives oxygen and nutrients from the blood supply of the ______

dermis (papillary dermis is also an acceptable answer)

the epidermis is composed of ______ cells, which are flattened, disk-shaped cells arranged into multiple layers

stratified squamous

the epidermis has 4 to 5 layers, which are mostly ______

keratinocytes

as keratinocytes divide and differentiate, they migrate from the ______ to more ______ layers

deeper; superficial

when keratinocytes migrate, they expel their ______ and produce additional ______

nuclei; keratin

eventually, fully differentiated keratinocytes are shed during ______

epidermal turnover

the 5 layers of the epidermis from superficial to deep are ______

1. stratum Corneum

2. stratum Lucidum

3. stratum Granulosum

4. stratum Spinosum

5. stratum Basale

what are some mnemonics to remember the order of the 5 layers of the epidermis from superficial to deep?

Come Lets Get Some Beers/Come Lets Go Sun Bathing

stratum Corneum

stratum Lucidum

stratum Granulosum

stratum Spinosum

stratum Basale

the stratum corneum is composed of dead, fully differentiated keratinocytes known as ______

corneocytes

corneocytes are flattened cells of ______

keratin

the stratum _____ provides protection against infection, dehydration, and physical harm

corneum

the stratum ______ has dead keratinocytes like the stratum corneum; however the keratinocytes are not fully differentiated into ______

lucidum; corneocytes

the stratum lucidum is only present in the _____ and the _____

palms of the hand; soles of the feet

the stratum granulosum is mostly ______ that migrated from the stratum ______

keratinocytes; spinosum

the keratinocytes in the stratum granulosum secrete ______ that form lipid-containing, hydrophobic membrane. This helps create the skin's ______

lamellar bodies; water barrier

the stratum spinosum provides skin with strength and flexibility because of its high prevalence of _____ that hold keratinocytes together

desmosomes

the stratum spinosum contains the highest prevalence of _____ cells of all the epidermal layers

Langerhans

Langerhans cells, which are the ______ cells of the epidermis. This is because the are intregral to communication between the _____ and _____ immune systems

dendritic;

innate; adaptive

the stratum _____ provides continuous renewal of the epidermal ______, via keratinocyte stem cells

basale; keratinocytes

_____ are located in the stratum basale, and they generate the pigment melanin

melanocytes

melanin is transported to ______, and it is responsible for the skin's ______ and protection from ______

keratinocytes; pigmentation; UV radiation (this is why individuals with greater levels of skin pigmentation generally have lower levels of skin cancer)

______ cells are located in the stratum basale, and they are specialized mechanoreceptor cells

Merkel

Merkel cells are specifically attuned to respond to _____ touch sensations, which is why they are extremely abundant in finger tips

light

each Merkel cell synapses with a ______ (hint: "body") afferent nerve fiber, which conveys the message to the central nervous system

somatosensory (somato = body)

a ______ is a cell that has the ability to respond to external stimuli

mechanoreceptor

the dermis is located just deep to the ______

epidermis

the _____ is a network of dense irregular connective tissue

dermis

the dermis functions to cushion the body from injury and provide a home for functional structures of the skin - what are some examples of those structures?

vessels, glands, nails, and hair

the dermis has ______ layers

2

the papillary dermis is named for its _____, which are small nipple-like, upward projections of the dermis towards the epidermis

dermal papillae

the more superficial, thinner layer is the ______ dermis, the deeper and thicker layer is the _______ dermis

papillary; reticular

the ______ create our fingerprints and increase the surface area between the dermis and epidermis

dermal papillae

why is it good that the dermal papillae increase the surface area between the epidermis and dermis?

it increases the capacity for delivery of oxygen and nutrients to the epidermis, which relies on the blood vessels of the papillary dermis for nourishment and waste removal;

increases the strength of the junction between the dermis and epidermis

_____ and _____ are present within the dense, irregular connective tissue of the reticular dermis

collagen; elastic fibers

reticular fibers make the reticular dermis _____ and _____

strong; elastic

the _____ dermis contains blood vessels, sensory receptors, hair follicles, nail beds, and glands

reticular

______ generate hair and keep it attached to the body surface

hair follicles

hair is a _____ filament that protects mammals from ______ and ______

keratin protein; UV radiation; hypothermia

_____ attach to hair follicles to erect the hair

erector pili muscles

*think of "goosebumps," in some mammals it plays a role in temperature regulation and scaring off predators

_____ glands are composed of specialized cells that create and secrete a product through a duct to an external surface, such as the skin or GI tract

exocrine

______ glands are exocrine sweat glands

sudoriferous

sudoriferous glands come in two types: ______ and ______, which differ in their location and product

eccrine; apocrine

______ glands are the main sweat glands of the body, and they are important for ______regulation

eccrine; thermo (thermoregulation is regulation of body temperature)

eccrine glands are located throughout the entire body surface, but they are most abundant in the ______ (armpit), palms of the hands, and the soles of the _____

axilla (armpit); feet

apocrine glands have more ______ and ______ sweat secretions than eccrine glands

oily; viscous

unlike eccrine glands, apocrine glands secrete their products into the _____ and are found in specific locations

hair follicle

what are some of the specific locations where apocrine glands are found?

armpit, nipple, ear canal, eyelid, nostril, and parts of the pubic area

______ glands are specialized apocrine glands that product ear wax

ceruminous glands

ceruminous glands produce _____, which is secreted into the external auditory canal

earwax (cerumen)

______ glands are specialized apocrine glands that produce milk

mammary

mammary glands are located below the ______

nipple (areola)

_____ glands secrete oily and waxy products (sebum) into the hair follicle

sebaceous

sebum ______ and ______ the hair and surrounding skin

lubricates; waterproofs

sebaceous glands are located throughout the entire body surface with the exception of the _______ and the ______

palms of the hands; soles of the feet

the ______ is located beneath the dermis, and it is not considered to be a part of the skin

hypodermis (hypo = below)

(part of the integumentary system)

the hypodermis is also called the ______ tissue

subcutaneous

the _____ contains larger nerves, blood vessels than those in the dermis

hypodermis

the main components of the hypodermis are ______ tissue and ______ tissue

loose connective; adipose (fat)

the main function of the hypodermis is _____

fat storage

it helps to conserve body heat, and it helps prevent injury by acting as a shock absorber

There are three types of epithelial cells, which are based on their ______

shape

the three types of epithelial cells are ______ (flattened); ______ (as wide as they are tall); and _______ (taller than they are wide)

squamous; cuboidal; columnar

if the epithelial cells are arranged as a single layer, it is referred to as ______; however, if they are arranged in multiple layers, they are considered ______

simple; stratified