Skin and Body Membranes: Dr. Joher B. Mendez, JR., RN
Skin and Body Membranes: Dr. Joher B. Mendez, JR., RN
Skin and Body Membranes: Dr. Joher B. Mendez, JR., RN
, RN
• Epithelial membranes
• Cutaneous membranes
• Mucous membranes
• Serous membranes
• Connective tissue membranes
• Synovial membranes
Mucosa of
lung bronchi
• Synovial membrane
• Connective tissue only
• Lines fibrous capsules surrounding joints
• Secretes a lubricating fluid
Joint cavity
(contains
synovial fluid)
Articular (hyaline)
cartilage
Fibrous
capsule
Articular
Synovial capsule
membrane
• Epidermis—outer layer
• Stratified squamous epithelium
• Cornified or keratinized (hardened by
keratin) to prevent water loss
• Avascular
• Most cells are keratinocytes
• Non-Keratinocytes
• Melanocytes
• Langerhans cells
• Merkel Cells
© 2012 Pearson Education, Inc.
Skin Structure
• Dermis
• Subcutaneous tissue (hypodermis) is deep to
dermis
• Not technically part of the skin
• Anchors skin to underlying organs
• Composed mostly of adipose tissue
• Stratum lucidum
• Formed from dead cells of the deeper strata
• Occurs only in thick, hairless skin of the
palms of hands and soles of feet
• Stratum corneum
• Outermost layer of epidermis
• Shingle-like dead cells are filled with keratin
(protective protein prevents water loss from
skin)
• Two layers
• Papillary layer (upper dermal region)
• Projections called dermal papillae
• Some contain capillary loops
• Others house pain receptors and touch
receptors
• Reticular layer (deepest skin layer)
• Blood vessels
• Sweat and oil glands
• Deep pressure receptors
Papillary layer
of dermis
Reticular layer
of dermis
• Fibroblasts
• Mast cells
• Blood vessels and cutaneous sensory
nerves
• Skin appendages
• Melanin
• Yellow, brown, or black pigments
• Carotene
• Orange-yellow pigment from some vegetables
• Hemoglobin
• Red coloring from blood cells in dermal capillaries
• Oxygen content determines the extent of red
coloring
• Hemoglobin
• Hair color?
• Dark hair?
Sebaceous Eccrine
gland gland
Dermal connective
tissue
Sebaceous
gland duct
Hair in
hair follicle
Secretory cells
• Composition
• Mostly water
• Salts and vitamin C
• Some metabolic waste
• Fatty acids and proteins (apocrine only)
• Function
• Helps dissipate excess heat
• Excretes waste products
• Acidic nature inhibits bacteria growth
• Odor is from associated bacteria
• Hair follicle
• Hair papilla
• Hair shaft
• Hair color
• Arrector pili
• Hair anatomy
• Central medulla
• Cortex surrounds medulla
• Cuticle on outside of cortex
• Most heavily keratinized
(b) Hair
© 2012 Pearson Education, Inc. Figure 4.8b
Appendages of the Skin
• Nails
• Scale-like modifications of the epidermis
• Heavily keratinized
• Stratum basale extends beneath the nail bed
• Responsible for growth
• Lack of pigment makes them colorless
• Nail structures
• Free edge
• Body is the visible attached portion
• Root of nail embedded in skin
• Cuticle is the proximal nail fold that projects
onto the nail body
(a)
• Inflammation =
normal response to
injury or stress
• Epidermal cuts
• Deep cuts
• Blood clots
• Scabs
• Scars
• Burns
• Tissue damage and cell death caused by
heat, electricity, UV radiation, or chemicals
• Associated dangers
• Dehydration
• Electrolyte imbalance
• Circulatory shock
Perineum, 1%
9% 9%
• First-degree burns
• Only epidermis is damaged
• Skin is red and swollen
• Second-degree burns
• Epidermis and upper dermis are damaged
• Skin is red with blisters
• Third-degree burns
• Destroys entire skin layer; burned area is painless
• Burn is gray-white or black
• Infections
• Athlete’s foot (tinea pedis)
• Caused by fungal infection
• Boils and carbuncles
• Caused by bacterial infection
• Cold sores
• Caused by virus
• Malignant melanoma
• Most deadly of skin cancers
• Cancer of melanocytes
• Metastasizes rapidly to lymph and blood
vessels
• Detection uses ABCD rule
• 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