Chapter 11.10 - Integumentary System Flashcards
Skin is composed of what two layers?
epidermis and dermis (not including hypodermis)
___ is the most superficial layer of the skin
epidermis
The epidermis is ___ and ___
thin; avascular
How does the epidermis receive oxygen and nutrients?
via diffusion from neighboring cells
What kind of cells is epidermis made of?
stratified squamous cells
What do stratified squamous cells look like?
flattened, disk-shaped cells arranged into multiple layers (4-5 layers of keratinocytes)
Layers of epidermis from superficial to deep
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
Where is stratum lucidum present?
only in the palms of the hands and the soles of the feet
Stratum corneum is composed of:
dead, fully differentiated keratinocytes (corneocytes)
Stratum corneum function
provides protection against infection, dehydration, physical harm
Stratum lucidum is composed of:
dead keratinocytes that have not yet fully differentiated to corneocytes
Stratum granulosum composed of:
keratinocytes
What does Stratum granulosum secrete?
lamellar bodies (helps form hydrophobic membrane to create water barrier)
Function of stratum spinosum
provides skin with strength and flexibility via desmosomes
Which layer of the epidermis contains the highest amount of Langerhans cells?
Stratum spinosum (they are present in all layers but most prevalent in spinosum)
Langerhans cells are:
dendritic cells of the epidermis
Stratum basale is separated from the dermis by the:
basement membrane (basal lamina)
How does the stratum basale attach to the basement membrane?
via hemidesmosomes
stratum basale provides continuous renewal of:
epidermal keratinocytes
stratum basale houses specialized cell types like:
melanocytes; merkel cells
Melanocytes generates:
melanin
Melanin is responsible for:
skin’s pigmentation and protection from UV radiation
Merkel cells are:
specialized mechanoreceptor cells
Merkel cells are specifically attuned to respond to:
light touch sensations (hence why they are very abundant in the fingertips)
Where is the dermis located?
Just deep to the epidermis
Structure and function of dermis
network of dense irregular connective tissue that functions to cushion the body from injury + provides home for vessels, glands, nails, hair
the dermis has _ layers
2
What are the layers of the dermis called?
papillary dermis; reticular dermis
The papillary dermis contains:
dermal papillae
Function of dermal papillae
- creates fingerprints
- increases surface area between dermis and epidermis to increase capacity for delivery of O2 and nutrients since epidermis is avascular 3. also increases strength of junction between dermis and epidermis
Reticular dermis is made of:
reticular fibers, collagen, elastic fibers
reticular dermis is what kind of tissue?
dense, irregular connective
What is contained in the reticular dermis?
blood vessels, sensory receptors, hair follicles, nail beds, glands
Hair is essentially a:
keratin protein filament
Function of hair
though still under debate in humans, protects mammals from UV radiation and hypothermia
___ attach to the hair follicle and cause it to erect the hair
Muscles (this causes goosebumps)
Exocrine glands
composed of specialized cells that create and secrete a product through a duct to the external surface
Sudoriferous glands
aka sweat glands, come in 2 types: eccrine and apocrine
____ ___ are the main sweat glands of the body
eccrine glands
Where are eccrine glands located?
throughout entire body surface; most abundant in the armpit, palms of hands, soles of feet
Eccrine glands are important for:
thermoregulation
Secretion from apocrine glands is more ____ and ____ compared to eccrine glands
oily and viscous
Apocrine glands secrete their products into the:
hair follicle
Where are apocrine glands located?
armpit, nipple, ear canal, eyelid, nostril, parts of the pubic area
Ceruminous glands
produce ear wax (cerumen) secreted into the external auditory canal
Mammary glands are specialized:
apocrine glands
Sebaceous glands
secrete oily/waxy sebum into hair follicle - lubricates and waterproofs the hair and surrounding skin
Where are sebaceous glands located?
everywhere except palms and soles of feet
Hypodermis is located:
deep to dermis
Another name for the hypodermis:
subcutaneous tissue
Hypodermis main components
loose connective tissue and adipose tissue
Main function of hypodermis
fat storage