Topic 9: Integumentary System - Epidermis Flashcards
What does the integumentary system consist of? (4)
- skin
- hair, nails, glands
- sense receptors (nervous)
- muscles
What are the two skin layers?
epidermis and dermis
The upper layer of the skin is ____
epidermis
The lower layer of the skin is ____
dermis
The layer below the skin is ___
hypodermis
What kind of tissue specifically is the epidermis layer?
- stratified squamous epithelium from ectoderm
Is epidermis vascular?
- no, since it is made up of epithelium tissue
What are strata (layers) of epidermis based on skin types? (5)
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
How many rows of cells does the stratum basale have?
- one row of cells
note that these are more cuboidal
What are the two cell types in stratum basale?
- keratinocytes
- melanocytes
What is the function of keratinocytes? (3)
- undergo mitosis
- make keratin (tough protein)
- migrate to surface as new cells produced in basale
What is the function of melanocytes?
- produce pigment (melanin) for UV light protection
ex. sunburns, wrinkles (collagen damage), cancer (DNA damage)
How do melanocytes affect our skin colour?
- we all have the same relative number of melanocytes, but cells produce different amounts/shades of melanin
What is it called when no melanin is produced in a person?
albinism/achromia
What is visible in areas of thin skin?
- blood (hemoglobin) is visible
- gives skin pinkish tinge
ex. nail bed/lips