Integumentary system Flashcards
Integument
-Is the largest system of the body->16% of body weight
-Protects and interacts with all organ systems
-Changes in skin appearance are used to diagnose disorders in other system
Made up of 2 parts
-Cutaneous membrane (skin)-> epidermis and dermis
-Accessory structures within the dermis
Hypodermis (superficial fascia or subcutaneous layer
-Loose Connective tissue
-Below the dermis
-Location of hypodermic injection
Cutaneous membrane function
-Physical protection from environmental hazards
Storage of lipids
-Coordination of immune response to pathogens and cancers in sking
Accessory structures functin
-Sensory information
-Synthesis of vitamin d2
-Excretion
-Thermoregulation
Epidermis
-Protects the dermis, prevents water loss and the entry of pathogens, and synthesizes vitamin d, sensory receptors detect touch, pressure, pain, and temperature
Dermis
Papillary layer- Nourishes and supports epidermis
Reticular layer- Has sensory receptors that detect touch, pressure, pain, vibration, and temperature. Blood vessels assist in thermoregulation
Hair follicles
-Hair protect skull and provide delicate touch sensation on general body surface
Exocrine glands
-Assist in temperature regulation and waste excretion
Nails
-Protect and support tips of fingers and toes
Function of integumentary system
-Protection of underlying tissues and organs
-Excretion of salts, water, and organic wastes (glands)
-Maintenance of body temperature (insulation and evaportation)
-Production of melanin
Functions of integumentary system
-Production of keratin
-Synthesis of vitamin D3
-Storage of lipids
-Detection of touch, pressure, pain, and temperature
Epidermis
-Consists of Keratinized stratified squamous epithelium
-Avascular (as all epithelia lack blood vessels)
-Depend on the diffusion of nutrients and oxygen diffuse from capillaries of underlaying connective tissue (dermis)
Epidermis
-Separated from the dermis by a basement membrane
-The deepest layer of the epidermis and the underlying dermis interlock, strengthening the bond between the two
Keratinocytes
-Main epidermal cells
-Contain large amounts of keratin -> tough fibrous protein
Stem cells
-Undifferentiated cells that give rise to keratinocytes
-Found in the deepest layer of the dermis (stratum basale)
Melanocytes
-Synthesize pigment melanin that shields DNA from ultraviolet radiation
-Occur only in stratum basale but have branched processes that spread among keratinocytes and distribute melanin
Tactile Cells
-Touch receptor cells associated with the dermal nerve fibers
-In basal layer of epidermis
Dendritic cells
-Macrophages originating in bone marrow that guard against pathogens
-Found in stratum spinosum and granulosum
layers of epidermis
-Two types of skin referring to the thickness of epidermis
Thin skin
-Covers most of the body
-Has four layers
Thick skin
-Covers the palms of the hands and soles of the feet
-Has five layers->from the basement membrane to free surface: Statum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
Stratum Basale
-Single layer of basal cells or germinative cells (stem cells) -> cells divide and give rise to keratinocytes that migrate towards skin surface to replace lost cells
-Is attached to basement membrane by hemidesmosomes
Stratum Basale
-Forms epidermal ridges that fit a complementary pattern of corrugation of the underlying dermis (dermal papillae)
-Forms a strong bond between epidermis and dermis
-Increase the area of basement membrane
-Strengthen attachment between wpidermis and dermis