Function of the skin
what ways does the skin protect from external environment
Protects body from injury, harmful substances, microbes, extreme temperatures, and UV radiation
How many layers are on the integument, name them
3, epidermis,dermis,Subcutaneous layer (hypodermis)
Classify Keratinocytes
Found in all layers
•Those in stratum basale are large stem cells
•Divide to regenerate new cells
•Synthesize keratin
•Protein that strengthens epidermis
List 4 functions of hair on the skin
Identification, protection, heat retention, sensory reception
Explain how the skin prevents water loss and gain
Epidermis is water resistant, not waterproof
•Water lost by sweat and transpiration
Primarily dense irregular connective tissue
Name 3 specialized cells of the epidermis
Dendritic (Langerhans) Cells,Melanocytes,Tactile (Merkel) Cells
what characteristics would Arrector pili include
Thin ribbons of smooth muscle
•Extend from hair follicle to dermal papillae
•Elevates hair with contraction, “goosebumps”
Explain how the skin helps with Temperature regulation
Dermal blood vessels capable of vasoconstriction to conserve heat or vasodilation to release heat
In the epidermis the first 3 layers are composed of what
living keratinocytes
Classify the Dendritic (Langerhans) Cells
Found in the stratum spinosum
•Phagocytes; protect skin and underlying tissues from infection
What is Alopecia areata
How does absorption work on the skin
Skin absorbs some chemicals/drugs but blocks others
•Selectively permeable
•Suitable for transdermal administration of some drugs
The first layer of the epidermis is what type of epithelial tissue
Stratified squamous
Classify Tactile (Merkel) Cells
Found in stratum basale
•Along with sensory nerve endings, for Tactile Discs in dermis
•Act as sensory receptors for light touch
What causes Diffuse hair loss
Name 8 functions of the skin
Protection from external environment,Prevention of water loss/gain,Vitamin D synthesis, Secretion,Absorption,Immune function,Temperature regulation,Sensory reception
Name all 5 layers of the epidermis
1.Stratum basale
2.Stratum spinosum
3.Stratum granulosum
4.Stratum lucidum
5.Stratum corneum
Classify Melanocytes
Found in stratum basale
•Produce the pigment melanin
•Absorbs UV light from sunlight and provides skin color
•Melanin is distributed to keratinocytes
•Transfer pigment granules (melanosomes) into keratinocytes
•Shield nuclear DNA from UV radiation
What is Androgenic alopecia and what causes it