Chapter 5 Flashcards
The Integumentary System consists of…
skin, hair, nails, sweat glands, sebaceous glands
epidermis
superficial region; epithelial tissue & avascular
dermis
fibrous connective tissue, vascular
Subcutaneous system is also called the…
hypodermis
The epidermis includes what four things?
keratinocytes, melanocytes, dendritic cells, tactile (merkel) cells
Keratinocytes
produces keratin (protein), protective, desmosomes
Melanocytes
melanin (absorbs UV radiation)
Dendritic cells
have patrolling immune cells
Tactile (merkel) cells
have sensory receptors that sense touch
Four layers of skin
stratum basale, stratum spinosum, stratum granulosum, stratun corneum
What happens in the Stratum Basale?
cells are constantly dividing (some stay as stem cells and others go off to be keratinocytes)
Stratum Spinosum
spikey which is created by desmosomes; immune system here
Stratum Granulosum
granules of keratin & lipids (lipids make skin waterproof)
Stratum Corneum
flattened, dead keratinocytes
Why do the skin cells die as they approach the Stratum Corneum?
there are no blood vessels, so they harden as they move away from the oxygen
What is the dermis?
connective tissue (ECM, fibers, fibroblasts, macrophages, mast cells, white blood cells), oil glands, hair
two layers of the dermis
Papillary (areolar/loose connective) & Reticular (dense irregular)
Papillary
loose fibers, finger-like projections
Which section of the dermis creates fingerprints?
papillary (dermal ridges)
Reticular
collagen and elastic fibers; contains the cutaneous plexus (network of blood vessels)
What are stretch marks?
striae (additional stretch to the dermis)
Three parts of hair shaft
Medulla, cortex, cuticle
Hair bulb
Extended area at deep end of follicle
Hair follicle receptor
Sensory nerve endings that wrap around the bulb
