Skin Flashcards
Functions of skin (5):
Protection (physical and immune), containment (prev dehydration), thermal regulation, sensation, and synthesis + storage
–Keratinized epithelium
* Tough, protective superficial layer
* Regenerative and pigmented basal layer
* No blood vessels or lymphatics (avascular)
* Less than 1 mm, except for soles of feet
Epidermis
(1-2 mm on average)
* Provide skin tone and account for strength and toughness of skin
- Most nerve terminals in here, a few penetrate
the epidermis
Dermis
Dermis: Supplied by arteries that enter its deep
surface to form a _____ of
anastomosing arteries
cutaneous plexus
Which layer of epidermis is regenerative and pigmented?
Basal Layer
- Most nerve endings (sensitive to touch,
irritation/pain, temperature) found here
dermis
Dermis: Dense layer of
interlacing ____ and ___ fibers
collagen and elastic
____ : accidental cuts and skin tears
Lacerations
Superficial Lacerations– penetrate the _____ and
sometimes ____, they bleed but
don’t interrupt the continuity of the dermis
epidermis. superficial layer of dermis.
Deep Lacerations– penetrate the deep layer of ______,
extending into the subcutaneous layer or beyond,
they gape and require approximation of the cut edge
of the dermis (by suturing) to minimize scarring
dermis
linear clefts in the skin that indicate the direction
of orientation of the underlying collagen fibers
Tension lines (cleavage lines, langer lines)
Tension Lines: Tend to spiral ____ in the limbs and run _____in the neck and trunk
longitudinally; transversely
Tension Lines: At joints, the lines are ____ to the transverse creases that
appear when the limbs are flexed
parallel
Cleavage lines are also known as tension lines or
langer lines
Incision or cut parallel to tension line results in
faster healing, less scar tissue
slower healing and increase in scar issue occurs when an incision is cut ____ to the tension line
oblique or perpendicular
a pilosebaceous unit includes:
hair follicles, arrector muscles of hairs, and sebaceous glands
Where will you NOT find hair follices:
(hair follicles are generally slanted to one side)
palms of hands,
soles of feet, lips, and urogenital orifices
Erects or raises hairs, causing goose bumps
- Activated under conditions of stress by
sympathetic nervous system
Arrector muscles of hairs (musculi arrector pili)
Sebaceous glands secrete what substance? What is the function of that substance?
sebum – an oily substance that protects
the skin from drying out
–Lie on the side the hair is directed towards as it
emerges from the skin (side with arrector muscle)
Sebaceous Glands
–Hormonal target and play a prominent role in acne
vulgaris from the formation of sebum plugs
Sebaceous Glands
Contraction of the ____ causes the
hairs to stand up straighter, thereby compressing
the sebaceous glands and helping them secrete
their oily product (sebum) onto the skin surface.
arrector muscles (smooth muscle)
what causes compression of the sebaceous glands, helping them secrete
their oily product (sebum) onto the skin surface.
Contraction of the arrector muscles causes the hair to stand up
Evaporation of sweat from the skin provides a ____
mechanism
cooling
Sweat glands are activated by ________
sympathetic nervous system
_____ Sweat glands: In axilla, around nipples, in pubic area
(labia majora, scrotum), in anal area.
Start to function during puberty
Apocrine
_____ Sweat glands: found everywhere except vermillion
border of lips, external ear
canal, nail beds, glans penis,
clitoris, and labia minora
Eccrine
____ Sweat glands: Secrete Mostly water with some ion
and nitrogenous waste
excretion
Eccrine
_____ sweat Glands: secrete Viscous, protein and lipid-rich product
that is initially odorless but can develop
odor after exposure to bacteria. Also
stimulated by adrenaline (NE)
aprocrine
Sweat glands playing a major role in thermoregulation
eccrine sweat glands
sweat glands serving as scent glands, minor role in thermoregulation
apocrine sweat glands
Large, branched sweat glands that release into hair follicles
Apocrine sweat glands
Sharp demarcation between the lip
and the adjacent normal skin
Vermillion Border of Lip
Vermillion Border of Lip: Represents change in the ____
from highly keratinized external skin to
less keratinized internal skin
epidermis
Epidermis is ____ on lip, so the blood
vessels are closer to the surface giving the
lip a reddish-pink to brown color
(depending on skin tone)
thinner