Integumentary System
SAP2. Students will analyze the
interdependence of the
integumentary, skeletal, and
muscular systems as these
relate to the protection, support
and movement of the
human body.
a. Relate the structure of the
integumentary system to its
functional role in protecting
the body and maintaining
homeostasis.
EQ: What role does the integumentary system
play in protecting the body and maintaining
homeostasis?
Cutaneous Membranes
1)
Cutaneous – (skin);
only epithelial
membrane that is dry
Integumentary System
► Most
roles are
protective
► Helps maintain
homeostasis
► Insulates body
► Keeps water and
molecules in body
► Protects organs from
bumps, cuts, etc.
Make-up of epidermis
► Epidermis
has no blood
supply (avascular)
► Most cells are
keratinocytes
 Produce keratin (tough
fibers which make skin
tough but pliable)
► Basement
Stratum Basale
membrane of
epidermis
► Vascularized
► Constantly undergoing
mitosis
► By the time cells reach the
surface, they are dead.
Melanin
► Cells
in stratum basale
take in melanocytes
(cells produce
pigment)
► Melanin
= body’s
natural sunscreen
Dermis
► Layer
directly beneath
the epidermis
► Highly
Vascularized
► Connective
tissue
Make-up of Dermis
► Mostly
collagen and
elastic fibers
► Fibers
bind with water
and keep skin hydrated
► Fibers
decrease with
age, and skin sags
Deep to the Dermis
► Subcutaneous
layer
 Also called hypodermis
 Adipose tissue
 Absorbs impact from
bumps, protects
organs; insulation
Skin Cancer
► Melanin
serves to protect
cellular DNA from
ultraviolet light
► When damage is done to
DNA, cancer can occur
► Basal Cell carcinoma
(least malignant)
► Squamous cell carcinoma
► Melanoma – darkened
blotches
 Cancer of the melanocyte
Papillary Layer
► Upper
dermal region
► Protrusions
into
epidermis called
dermal papillae
► Nourishes
epidermis
Also in Papillary Layer
► Meissner’s
corpuscles –
sensory receptors
(touch)
► Pain
receptors
► Papillary
pattern is
genetic, and forms
fingerprint
Reticular Layer
► Deep
layer
to papillary
► Contains
blood
vessels, sweat glands
and oil glands.
► Phagocytes
prevent
bacterial intrusion
Sweat Glands
► Controlled
system
► Two
by nervous
types
► 1) Eccrine
► 2)Appocrine
Sebaceous Glands
► Oil
Glands
 Ducts usually empty
into a hair follicle
 Secretes sebum
 Sebum keeps skin moist
and pliable
 Also produces acidic
compounds that kill
bacteria
Problems with oil glands
► Clogged
oil gland
becomes whitehead
► As whitehead
oxidizes, it becomes
darker (blackhead)
► Acne – infection of oil
gland
► Seborrhea- “cradle
cap”