Chapter 5- Integumentary System Flashcards
What system is the first line of defense against a hostile surrounding environment?
Integumentary
What are the two components of the cutaneous membrane (skin)?
Epidermis, dermis
**Functions of skin
- Protection of underlying tissues & organs
- Excretion of salts, water, and organic wastes (glands)
- Maintenance of body temp (insulation and evaporation)
- Production of melanin
- Production of keratin
- Synthesis of Vitamin D3
- Storage of lipids
- Detection of touch, pressure, pain, temp
- Coordination of immune response
What kind of tissue makes up the epidermis?
Avascular Stratified Squamous Epithelium
Thin skin
- covers most of the body
- has 4 layers of keratinocytes
Thick skin
- covers palms of hands and soles of feet
- has 5 layers of keratinocytes
- Stratum Corneum
-Layer you see, flat dead cell, many layers thick, upper layers are continuously sluffed off
- Stratum Lucidum
ONLY FOUND IN THICK SKIN
- Stratum Granolusum
-Cells start to flatten, Plasma membrane becomes thicker, organelles and cell dies off
- Stratum Spinosum
- Spiny structure
- keratinocytes
- Stratum Basale
- Mitotically active cells
- Produce cells for all other layers
- Cuboidal shaped
- Contains melanocytes
- 1 layer of cells thick!
Keratin
Tough, fibrous protein
Decreases water loss
Makes up hair and nails
What produces orange-yellow pigment in skin?
Carotene
-carrots, sweet potatoes
What produces red-yellow/brown-black pigment in skin?
Melanin
- melanocytes
- protects skin from sun damage
Blood circulation
- Blood vessels dilate from heat, skin reddens
- Blood flow decreases, skin pales
Cyanosis
- bluish skin tint
- caused by severe reduction of blood flow/oxygenation
Jaundice
- yellow color
- buildup of bile produced by liver
Vitiligo
- loss of melanocytes & color
- may develop when immune system malfunctions
Basal Cell Carcinoma
- most common skin cancer
- originates in stratum basale in response to UV radiation
- virtually no metastasis and most ppl survive
Malignant Melanoma
- cancerous melanocytes
- metastasize through lymphatic system
- detected early, 5-yr survival is 99%, detected until after metastasis, 5-yr survival is 14%
ABCDE rule to detect melanoma
A: Asymmetry: the two sides of the pigmented area do not match
B: Border exhibits indentations
C: Color is black, brown, tan, and sometimes red or blue
D: Diameter is larger than 6 mm (size of pencil eraser)
E: Evolving
Vitamin D3
-Epidermal cells produce CHOLECALCIFEROL (Vitamin D3) in the presence of UV radiation
-Liver and kidneys convert Vitamin D3 into Calcitriol
CALCITRIOL: Aids in absorption of calcium and phosphorus
Insufficient V.d3 can cause rickets
Two layers of the dermis
- Papillary: Areolar (arena for immune system), capillarys providing blood to epidermis
- Reticular: Dense irregular connective tissue (collagen & elastic fibers), large blood vessels
Dermal strength and elasticity
- Collagen fibers
- impart strength
- provide flexibilty and resists punctures - Elastic Fibers
- Permit stretching and then recoil to original length - Skin Turgor
- result of the fibers & water content
- Can be used to indication hydration levels
**Blood osmolarity
normal 300 osmol
above 300: Dehydrated - Hypotonic IV
below 300: Overhydrated - Hypertonic IV
Lines of Cleavage
clinically significant for surgery and wound healing
parallel to cleavage: better healing, less scarring
perpendicular to cleavage: remain open and more scarring
Dermal blood supply
Cutaneous plexus: A network of arteries along the reticular layer
Papillary plexus: Capillary network from small arteries in papillary layer
Nerve fibers in skin control
Blood flow
Gland secretions
Sensory receptors
Hypodermis (Subcutaneous Layer)
Made of elastic areolar and adipose tissues
F: -Cushioning, energy storage, insulation
Attaches to skin but allows independent movement
Hair follicles
- produce hairs that protect skull
- produce hairs that provide delicate touch sensations
Exocrine glands
- Assist in thermoregulation
- Excrete wastes
- Lubricate epidermis
Nails
Protect and support tips of fingers and toes
Functions of hair
protects and insulates
guards openings against particles and insects
sensory, sensitive to very light touch
**Repair of the integumentary system
- Inflammatory Phase
- bleeding occurs at the site of injury immediately after the injury, and mast cells in the region trigger an inflammatory response - Migratory Phase
- a scab forms and cells of the stratum basale are migrating along the edges of the wound.
- phagocytic cells remove debris - Proliferation Phase
- Epidermal cells migrated over the collagen fiber meshwork
- fibrin clot dissolving - Scarring Phase
- scab has been shed
- Fibroblasts continue to create scar tissue
