12.1 Epidermis & Dermis Flashcards
(21 cards)
Integumentary system two layers
Epidermis and dermis
Skin is what percent of your body weight
7% - largest organ
Skin functions
- protects from external environment
- regulated body temperature
- detects cutaneous sensations
- synthesis vitamin D
Vitamin D deficiency can lead to
Calcium deficiency (osteoporosis)
Thick skin found in
Palmar and plantar (no hair)
80% of skin
Dermis (CT dense irregular)
20% of skin
Epidermis - epithelial (stratified squamous)
Hypodermis
Subcutaneous fat/fascia
Epidermis is avascular
True
Epidermis is primarily
Primarily:
Keratinocytes (produce keratin)
- protection and waterproofing
Thick skin has more
Stratum corneum (dead cells)
Skin pigments
Hemoglobin & Melanin
Hemoglobin pigment
- capillaries near epidermis for thermoregulation
- allows crimson color of blood to show through
Melanin pigment
- melanocyte activity (not number) determines function (8% of epidermis)
- freckles are uneven distribution of melanin
- mole is cluster of melanocytes
- UV light damages DNA
Cancer is
Unrestricted growth
Three types of skin cancer
Basal cell carcinoma
Squamous cell carcinoma
Melanoma
Basal cell carcinoma
80-90% of skin cancers
Deepest Born layer of epidermis
Highly treatable
Squamous cell carcinoma
Occurs within living middle layer of epidermis
More aggressive
Highly treatable
Melanoma
A cluster of melanocytes
75% of all skin cancer deaths
Mole
Dendrites reach and deposit pigment to the upper epidermis layer.
If cancerous can reach down in dermis (blood supply)
UV-B dangerous
Epidermis deepest layer is:
In deepest layer of epidermis:
Melanocytes (produce melanin)
- UV protection & skin color
