Warm Up
• Why is your skin important for your body to
maintain homeostasis?
Skin and Body Membranes
Chapter 4 (p.110-127)
Objective Checklist
List the structure (tissue type) and functions
of each membrane and give its location in the
body
Name the layers of the integumentary system
and list characteristics of each
Differentiate between 1st, 2nd, and 3rd degree
burns
Describe three different types of skin cancer
Skin and Body Membranes
• Body membranes line,
protect, and lubricate
• Types of Membranes
include…
– Epithelial membranes
(cutaneous, mucous, and
serous)
– Connective tissue
membranes
Cutaneous Membrane
• Cutaneous membrane (skin)
– Keeps your dry!
– Outermost protective boundary
• Components
– Epidermis (keratinized stratified squamous
epithelium)
– Dermis (dense connective tissue)
– Hypodermis (adipose tissue)
• Not considered part of the skin
• Anchors skin to underlying organs
Cutaneous Membrane
Mucous Membranes
• Components
– squamous/columnar
epithelium (surface)
– areolar connective tissue
(underneath)
• Lines all body cavities that open to the
exterior body surface (respiratory, digestive,
urinary, and reproductive tracts)
• Moist and adapted for absorption or
secretion
Figure 4.1b
Review
Why do you need stratified
squamous tissue in your mouth?
Why do you need simple columnar
tissue in your stomach, intestines?
Why do you need pseudostratified
columnar tissue in your trachea?
Why do you need transitional
squamous tissue in your bladder?
Serous Membranes
• Composition
– simple squamous
epithelium (surface)
– areolar connective tissue
(beneath)
• Lines open body cavities
that are closed to the
exterior of the body
• Serous layers separated by serous fluid
Figure 4.1c
Serous Membranes
• Examples of serous membranes
– Peritoneum (abdominal cavity)
– Pleura (around lungs)
– Pericardium (around heart)
Why is there serous
fluid between the
two layers??
What do you call the OUTTER
membrane that surrounds the
HEART?
Figure 4.1d
Connective Tissue Membrane
(Synovial Membrane)
• Components
– Areolar connective
tissue
• Lines fibrous capsules
surrounding joints
• Cells there secrete
lubricating fluid
Why do you want lubricating fluid
in this area?
Figure 4.2
Now a Closer Look at Skin
Skin Derivatives
• Skin derivatives
– Sweat glands
– Oil glands
– Hairs
– Nails
Other Skin Functions
• Protects deeper tissues from:
–
–
–
–
–
–
Mechanical damage
Chemical damage
Bacterial damage
Thermal damage
Ultraviolet radiation
Desiccation
• Aids in heat regulation
• Aids in excretion of urea and uric acid
• Synthesizes vitamin D
Skin Structure in Detail
• The epidermis is avascular and
obtains nutrients from the
dermal layer
• The dermis contains blood
vessels, nerves, sweat glands,
and oil glands
• It also contains dermal papillae
that form ridges on the surface
of the skin
Skin Structure in Detail
Normal Skin Color Determinants
• Melanin
– Yellow, brown or black
pigments
• Carotene
– Orange-yellow pigment
from some vegetables
• Hemoglobin
– Red coloring from blood
cells in dermis capillaries
Appendages of the Skin
• Sebaceous glands
– Produce oil
• Lubricant for skin
• Kills bacteria
– Most with ducts that
empty into hair
follicles
– Glands are activated
at puberty
Appendages of the Skin
• Sweat glands
– Two types
• Eccrine
Bacteria
– Open via duct to pore on skin surface
– Widely distributed
– Used in thermoregulation
• Apocrine
Bacteria
– Opening associated with hair follicles
– Located in axillary and pubic regions
– Precise function unknown
Appendages of the Skin
• Hair
– Consists of hard
keratinized
epithelial cells
– Melanocytes
provide pigment
for hair color
– Muscles around
the root contract
when you are cold
Why does
your body do
that??
Appendages of the Skin
• Nails
– Scale-like modifications of the
epidermis
– Heavily keratinized
How much bone would
need to be removed
for your nail to never
grow back?
Burns
• Tissue damage and cell death caused by
heat, electricity, UV radiation, or chemicals
• Associated dangers
– Dehydration
– Electrolyte imbalance
– Circulatory shock
– Infection
Why are dehydration,
electrolyte imbalance, and
circulatory shock related?
What is circulatory shock?
Rule of Nines
• Way to determine
the extent of burns
• Body is divided into
11 areas for quick
estimation
• Each area represents
about 9%
Figure 4.11a
Severity of Burns
• First-degree
– Only epidermis is damaged
– Skin is red and swollen
• Second degree
– Epidermis and upper dermis
are damaged
– Skin is red with blisters
• Third-degree
– Destroys entire skin layer
– Burn is gray-white or black
Critical Burns
• Burns are considered critical if:
– Over 25% of body has second degree burns
– Over 10% of the body has third degree burns
– There are third degree burns of the face, hands, or
feet (suffocation and/or loss of function)
Skin Cancer Types
• Basal cell carcinoma
– Least malignant, most common
– Dome shaped w/ pearly appearance
• Squamous cell carcinoma
– Metastasizes to lymph nodes
– Early removal allows a good chance of
cure
– Shallow ulcer with firm, raised border
• Malignant melanoma
– Most deadly of skin cancers
– Metastasizes rapidly to lymph and blood
vessels
ABCD Rule for Melanoma
• A = Asymmetry
– Two sides of pigmented mole do not match
• B = Border irregularity
– Borders of mole are not smooth
• C = Color
– Different colors in pigmented area
• D = Diameter
– Spot is larger then 6 mm in diameter
ABCD Rule for Melanoma
Objective Checklist
List the structure (tissue type) and functions
of each membrane and give its location in the
body
Name the layers of the integumentary system
and list characteristics of each
Differentiate between 1st, 2nd, and 3rd degree
burns
Describe three different types of skin cancer