INTEGUMENTARY
SYSTEM
Hazel B. Ancajas, LPT
INTRODUCTION
ORGANS are body
structures
composed of two or
more different
tissues that perform
specific functions.
the skin and its
accessory organs make
up the
INTEGUMENTARY
SYSTEM.
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Interesting Facts:
✔ Nails: Your nails grow .5mm per week.
✔ Hair: The average amount of head hair is 120,000.
Hair grows 1cm per month.
✔ Skin: The body’s largest sensory organ, and also the
largest organ. 12-15% of body weight, with a surface
area of 1-2 meters.
Every month you have a whole new layer of skin.
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FUNCTIONS OF THE SKIN
Your skin protects your body
against infection and extreme
temperatures, maintains your
balance of fluids, and even
synthesizes vitamin D for
your own personal use.
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FUNCTIONS OF THE SKIN
Your skin can retard water
loss and it is the house
sensory receptors. Skin cells
synthesize certain
biochemicals and a pathway
to excrete wastes.
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Layers of The Skin
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An outer EPIDERMIS of avascular keratinized stratified squamous
epithelium
The DERMIS connective tissue and blood vessels
The SUBCUTANEOUS LAYER (hypodermis) of areolar and
adipose tissues
▪ Insulates to conserve body heat
and impedes entrance of
external heat
▪ Contains major blood vessels
EPIDERMIS
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Keratinocytes: These cells make up the
majority of the epidermis. They form a
barrier for the body against the outside
world.
Melanocytes: These cells make a protein
called melanin, which is a pigment that gives
skin a darker color. More melanin means
darker skin. Melanin also protects skin cells
from ultraviolet damage.
Merkel cells: These are “neuroendocrine
cells,” meaning that they look like nerve cells
but also have some features of hormone cells.
Their exact function is not known, but they
are thought to play a role in sensing light
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Stratum granulosum
• Keratinization begins
• 3-5 layers of flattened keratinocytes
undergoing apoptosis
Stratum spinosum
• Several layers of keratinocytes joined together
by desmosomes and tight junctions
• Named for appearance of cells after histological
preparation (spiny/prickly)
• Also contains some dendritic cells
Stratum basale
• Also referred to as stratum germinatum
because this is where new cells are formed
• Deepest layer of the epidermis
• Single row of cuboidal or
columnar keratinocytes
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Layers of epidermis
Stratum corneum
•25-30 layers of dead flat
keratinocytes
•Shed continuously and replaced
by cells from the deeper strata
•Serves as a water, microbe, injury
barrier
Stratum lucidum
•3-5 layers of clear, flat, dead
keratinocytes
•Dense packed intermediate
filaments
•Present only in thick skin
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•Thick
plasma membranes
DERMIS
The dermis, generally
the thickest of the three
skin layers, contains
blood vessels,
lymphatic vessels, hair
follicles, sweat glands,
oil glands, nerve
endings, and fibrous
tissue. The dermis is
made up of two layers:
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DERMIS
Papillary layer
• Superficial portion of the dermis
• Consist of areolar connective
tissue
containing elastic fiber
• Epidermal ridges conforms to the
dermal papillae
Reticular layer
• Deeper portion of the dermis
• Consist of dense irregular
connective
tissue containing
collagen
or elastic fibers
• Contains hair follicles, nerves,
sebaceous and sudoriferous
glands
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DERMIS
• Collagen fibers make up
70% of the dermis and
give structural toughness
and strength.
• Elastin fibers are loosely
arranged in all directions
and give elasticity to the
skin.
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DERMIS
The dermis binds the epidermis to
underlying tissues. Epidermal ridges
and dermal papillae cause the border
to be uneven.
Genetically determined pattern of
friction ridges formed by dermal
papillae give unique fingerprints.
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DERMIS
Dermal blood vessels carry
nutrients to upper layers of skin
and help to regulate temperature.
The dermis also contains nerve
fibers, sensory receptors, hair
follicles, sebaceous glands,
and sweat glands.
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HYPODERMIS
The subcutaneous
layer, also called the
hypodermis or the
subcutis, is the
innermost layer of the
skin. It contains fat
cells and collagen cells,
as well as connective
tissue, bigger blood
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HYPODERMIS
Hypodermis
• Subcutaneous tissue
• Has more areolar and adipose than
dermis has
• Pads body and binds skin to underlying
tissues
• Common site of drug injection since it has
many blood vessels
Subcutaneous fat
• Energy reservoir
• Thermal insulation
• Thicker in women
• Thinner in infants, elderly
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SKIN COLOR
❖
Skin color results from a combination of genetic,
environmental, and physiological factors.
❖
Genetic differences in skin color result from differing amounts
of melanin and in the size and distribution of melanin granules.
❖
Exposure to sunlight, UV light from sun lamps, and X- rays
cause darkening of skin as melanin production increases.
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SKIN COLOR
Circulation within
dermal blood vessels
affects skin color.
▪ Well oxygenated
blood gives a pinkish
color
▪ Poorly oxygenated
blood gives cyanosis.
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SKIN COLOR
Yellowish skin color can
come from eating too many
food with carotene or from
cyanosis due to liver disease.
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SKIN COLOR
✔ Melanin—most significant factor in skin color
– Produced by melanocytes, accumulates in
keratinocytes
– Two forms of the pigment:
• Eumelanin—brownish black
• Pheomelanin—reddish yellow
(sulfur-containing)
✔ People of different skin colors have the
same number of melanocytes
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– Darker skinned people
• Produce greater quantities of melanin
• Melanin breaks down more slowly
• Melanin granules more spread out in
keratinocytes
• Melanized cells seen throughout the
epidermis
– Lighter skinned people
• Melanin clumped near keratinocyte
nucleus
• Little melanin seen beyond stratum basale
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ACCESSORY STRUCTURES OF THE SKIN
NAILS
Nails are protective coverings over the ends of fingers and toes.
Nails consist of a nail plate and stratified squamous epithelial cells
overlying the nail bed, with the lunula as the most actively growing
region of the nail root.
As new cells are produced, older ones are pushed outward and
become keratinized.
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ACCESSORY STRUCTURES OF THE SKIN
HAIR
Hair can be found in nearly all regions of the skin except palms,
soles, lips, nipples, and portions of external genitalia.
Each hair develops from epithelial stem cells at the base of a
tube-like depression called the hair follicle. The dermis contain the
hair root.
As new cells are formed, old cells are pushed outward and become
keratinized, and die forming the hair shaft.
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ACCESSORY STRUCTURES OF THE SKIN
HAIR
Hair color is determined by genetics; melanin from melanocytes is
responsible for most hair colors. Dark hair has eumelanin (brownish-black),
while blonde and red hair have pheomelanin (reddish-yellow).
Genetic lack of melanin causes albinism (white).
A bundle of smooth muscle cells, called the arrector pili muscle, attaches to
each hair follicle. These muscles cause goose bumps when cold or frightened.
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10/7/2021
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ACCESSORY STRUCTURES OF THE SKIN
SKIN GLANDS
Sebaceous glands (holocrine glands) are associated with hair follicles and
secrete sebum that waterproofs and moisturizes the hair shafts and skin.
Sweat glands (sudoriferous glands) – merocrine; The secretions exit
via a surface pore.
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Eccrine - which respond to body temperature
Apocrine, which become active at puberty and respond to body temperature,
stress, and sexual arousal. Most numerous in axilla and groin.
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SWEAT GLANDS
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ACCESSORY STRUCTURES OF THE SKIN
SKIN GLANDS
Modified sweat glands,
called ceruminous
glands, secrete wax in
the ear canal.
Mammary glands,
another type of
modified sweat gland,
secretes milk.
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WHAT ARE YOUR SKIN & HAIR
PRODUCTS?
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HEALING OF WOUNDS
Inflammation, in which
blood vessels dilate and
become more permeable,
causing tissues to become
red and swollen, is the body's
normal response to injury.
Superficial cuts are filled
in by reproducing
epithelial cells.
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A deeper injury with broken
blood vessels involves the
formation of a blood clot.
• The blood clot and dried tissue fluids
form a scab.
• Fibroblasts migrate into the area and
secrete collagen fibers to bind the edges
of the wound together.
• Phagocytotic cells remove debris and
dead cells.
• Damaged tissue is replaced and the scab
sloughs off.
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If the wound is deep, extensive production of
collagenous fibers may form an elevation above the
normal epidermal surface forming a scar.
Large wounds leave scars and healing may be
accompanied by the formation of granulations.
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A new branch of a blood vessel grows into the area.
The vessel is accompanied by a cluster of fibroblasts that
begin repair.
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• Burns—leading cause of accidental death
BURNS
– Fires, kitchen spills, sunlight, ionizing radiation, strong acids or bases,
or electrical shock
– Deaths result primarily from fluid loss, infection, and toxic effects of
eschar (burned, dead tissue)
– Debridement: removal of eschar
• Classified according to depth of tissue involvement
– First-degree burn: involves only epidermis
• Redness, slight edema, and pain
• Heals in days
– Second-degree burn: partial-thickness burn; involves part of dermis
• May appear red, tan, or white; blistered and painful
• Two weeks to several months to heal and may leave scars
– Third-degree burn: full-thickness burn; involves epidermis, all of
dermis, and often some deeper tissues
• Often requires skin grafts
• Needs fluid replacement, infection control, supplemental nutrition
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DEGREES OF BURN INJURIES
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“The finest clothing made is a
person’s own skin, but, of
course, society demands
something more than this.”
~Mark Twain~
8/03/20XX
PITCH DECK
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