Module 6 - Integumentary System Flashcards
Cutaneous Membrane
aka Skin; largest heaviest organ; Consists of two layer - epidermis & dermis
What tissue is the epidermis made up of
stratified squamous epithelium
What tissue is the dermis made up of
Connective Tissue
Subcutaneous membrane
aka Hypodermis; below dermis; consists of connective tissue
Functions of skin
Resistance to trauma & infection Barrier functions Vitamin D Synthesis Sensation Thermoregulation Nonverbal Communication
Epithelium
densely packed cells (keratinocytes) and proteins (keratin). Acidic and dry
Characteristics of Epidermis
Dead cells at surface packed with keratin
Avascular - lacks blood vessels
Depends on diffusion nutrients
Contains nerve endings for touch & pain
List the layers of the Epidermis - Deep to Superficial
Stratum Basale Stratum Spinosum Stratum Granulosum Stratum Lucidum Stratum Corneum
Stratum Basale: Fxn & Cells Found here
Site for new skin production;
Composed of stem cells that divide and become keratinocytes, Melanocytes and Tactile Cells
Melanocytes
produce melanin which absorbs UV light
Tactile Cells
attached to neurons in underlying dermis and allow for sensation
Stratum Spinosum
thickest layer except for thick skin; consists of keratinocytes and dendritic cells
Dendritic Cells
type of WBCs patrol skin looking for invaders
Stratum Granulosum
consists of 3-5 layers of keratinocytes; Keratin is produced creating a waterproof barrier
Why do Keratinocytes die off as they move toward the surface
as they move away from the stratum Basale they lack the oxygen needed
Stratum Lucidum
found only in think skin; soles of feet and palms; Keratinocytes densely packed with keratinocytes
Stratum Corneum
30+ layers of dead keratinocytes and keratin; resistant to abrasion and water loss
How long does it take for keratinocytes to make its way to the surface?
30-40 days
The distinct line between the dermis and epidermis is formed by what?
Dermal Papillae & epidermal ridges; working like finger projections that lock together to prevent slipping
Name the two layers of the dermis
Papillary & reticular layer
Papillary Layer
Layer of Dermis: thin layer near dermal papillae consisting of areolar loose CT and blood vessels
Reticular Layer
Layer of Dermis; thick layer deep to papillary layer; consists of dense irregular CT.
What Layer contains glands, hair & follicles?
Dermis
Hypodermis
aka subcutaneous membrane; Vascular; binds underlying tissue, consists of more areolar and adipose tissue
