Describe layers of skin - ANSWER There are two layers:
- Epidermis
- Dermis
What is Epidermus Layer? - ANSWER Outer layer of stratified squamous epithelium
What is Dermis Layer? - ANSWER Deeper connective tissue layer
• Compare thick and thin skin - ANSWER Thin skin: 0.5 - 1-2mm
Thick skin: up to 6mm
• Describe the epidermis in detail - ANSWER Superficial to Dermis, Keritinized stratified
squamous epithelium, NO BLOOD CELLS AVASCULAR.
• Describe the 5 zones/layers of the epidermis - ANSWER STRATUM:
Cornuem
Lucidum
Granulosum
Spinosum
Basale
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,• Explain the functions of different types of cells that reside in the various layers of the epi-
dermis - ANSWER Basale: cells that divide quickly and produce tough fibrus protein fila-
ments, sense touch.
Spinosum: THICKEST, cells alert immune system.
Granulosum: - 3-5 layers of granule and vesicle and cells form protein-lipid epidermal water
barrier.
Lucidum: THIN, cells are filed with eledin.
Cornuem: Dead, scaly keratinized cells.
• Describe the function of melanin - ANSWER PRODUCE PIGMENT
Melanin shapes and produces skill color, depending on Eumelanin and Pheomelanin pro-
duced in body.
• Describe how eumelanin and pheomelanin contribute to skin color - ANSWER
Eumelanin: black/brown
Pheomelanin: reddish/yellow
• Explain how the epidermal- water barrier is created and its function - ANSWER It is cre-
ated in Stratum Granulosom. forms a protein-lipid epidermal water barrier.
• Explain why epithelial cells get flat as they ascend toward the surface of the skin - AN-
SWER They die as they get closer to the skin because they get cut off from nutrients.
• Explain the ecological role of dust mites in the environment - ANSWER They feed off
dead skin.
• Describe the dermis - ANSWER 0.2-4mm of fibrous connective tissue composed of col-
lageen with elastic and reticular fibers.
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, • Define dermal papilla and piloerector muscles - ANSWER Dermal Papillae: upward ex-
tensions of dermis into epidermous forming ridges.
Pilorector muscles: smooth muscle.
• Explain the roles of the two different types of connective tissues in the dermis - AN-
SWER Papillary Layer: loose areolar tissue, to let WBC to move through.
Reticular Layer: dense irregular connective tissue responsible for connective tissue.
• Describe the structure and function of the hypodermis - ANSWER Structure: Subcuta-
neous tissue
Function: energy resevoir and thermal insulation.
• List terms that are synonymous with hypodermis - ANSWER Subcutaneous tissue
Superficial fascia.
• Recall the various pigments that can contribute to skin color - ANSWER Hemoglobin
(red)
Carotene (yellow)
• Describe hemangiomas - ANSWER freckles and moles
• List seven abnormal skin colors and their causes - ANSWER skin colors:
Blue
red
yellw
golden-brown
pale
genetic lack of melanin
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