Functions of the intugementary system
Mechanical barrier, protects internal structures, participates in immune response, gland for Vitamin D synthesis, performs secretion, performs sensory role, helps regulate temperature
Layers of the intugementary system
Epidermis <= epithelial tissue
Dermis <= connective tissue
Subcutaneous
Accessory structures
Layers of the epidermis
Stratum germinativum, deeper layer, cells divide and move toward surface
Stratum corneum, composed of dead flattened cells
Keratinization: begins in epidermis, makes skin cells hard, flat, water resistant
Function of the dermis
Lies under and supports the epidermis
Sits on the subcutaneous layer or hypodermis
Embedded with accessory structures
Skin tells a story
Reflects disease process, drug reactions, mirrors stress levels, chronic irritation
Subcutaneous layer: hypodermis
Tissue that lies beneath the skin, highly vascularlized
Roles: Insulates body from extreme temperature changes, its connective tissue anchors skin to underlying structures
Skins, drugs, and chemicals
Skin can absorb chemicals
Hypodermic= diabetes
Transdermal= patches
Intradermal= allergy test
Topical
What is skin color determined by?
Genes, physiology, sometimes pathology
Dark pigment
Melanin
Secreted by melanocytes in the epidermis
Melanocyte malfunctions: Albinism, vitiligo, moles
Yellow pigment
Carotene
Presence of melanin can overshadow carotene
Physiological changes
Blushing: blood dilation
Pallor: blood vessel contriction
Pathological changes
Cyanosis: poor oxygenation
Jaundice: bilrubin deposition
Bronzing: Melanin overproduction
Ecchymosis: black or blue bruising
Accessory structure
Hair, nails, glands
Hair
Functions: detect insects, protect eyes, keep dust out of lungs
Hormones affect hair growth
Melanin influences color
Where does hair arise from?
The epidermis
Nails
Free edge, nail body, nail root
Lunula (white part) shows nail growth
Protects tips of fingers and toes
Can reflect deficiencies or issues in blood
Glands
Sebaceous glands: Oil gland secretes sebum
Sudiferous: Sweat glands
Appocrine gland
Sudiferous gland
-Associated with hair follicle- more active during puberty
Eccicrine glands
Sudiferous gland
-Associated with temperature regulation
Modified sudiferous glands
Mammary glands: secrete milk
Cerumunous glands: secretes ear wax
Body temperature terms
Corm temperature: inner parts of body
Shell temperature: surface areas of the body
Thermoregulation: balance of heat production and heat loss
Heat production
Metabolism: basis of body temperature
Blood disperses heat throughout the body
Most heat produced by muscles, liver, and endocrine glands
Can be affected by food consumption, hormones, disease, and physical activity
The ways body heat is lost
Radiation (body radiates heat), evaporation (body heat –> sweat –> evaporates), conduction (direct contact with an object), convection (heat loss by air or water moving across the skin)
What is temperature regulated by?
The hypothalamus
-Heat lost by: Dilation of blood vessels, sweating
-Heat conserved by: Shivering, blood vessel; constriction, less sweat
Newborns and body temperature
Lost more heat than they produce
-Large surface area
-Large bald head
-Less insulation
-Limited capacity to dissipate heat
Because hypothalamus isn’t fully developed babies are at risk for hypothermia
Burns are classified by depth
Partial thickness: first, second degree
Full thickness: third degree
Rule of nines
Head and neck: 9%, 4.5/4.5
Arms hands and shoulders: 18% 4.5/4.5, 4.5/4.5
Chest: 36%, 18/18
Groin: 1%
Legs: 9% front and back each leg
