Integumentary System Flashcards
What does the integumentary system consist of?
- Skin
- Hair, nails, glands
- Sensory receptors
- Muscles
What are the layers of skin?
Epidermis (Upper) aka Superficial
Dermis (Lower) aka Deep
Below skin = Hypodermis (Deep to)
What are the characteristics of Epidermis?
- Stratified Squamous Epithelium
- Avascular
- Separated into 4 to 5 layers based on cell types
What are the cell types of Epidermis?
- Stratum Basale
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
What is stratum basale?
Single row of cells with 2 cell types.
- Keratinocytes
- Melanocytes
Keratinocytes make up 90% of these cells and undergo mitosis to make keratin. As new cells are produce, the old ones surface
Melanocytes make up 10% and produce pigment (melanin) for UV light protection.
How does different skin color and thin skin relate to melanocytes?
Everyone has the same amount of melanocytes, but cells make different shades of melanin. Some have no melanin = Albinism. In thin skin, blood can be seen as a pinkish color.
Characteristics of stratum granulosum?
Has dark staining granules.
Characteristics of Stratum Lucidum?
- Flat, dead cells b/c they are too far from blood supply and only visible in thick skin.
Characteristics of stratum corneum?
20 - 30 layers of flat, dead cells filled with keratin and surrounded by waterproofing glycolipids (prevents water loss). These cells are shed and replaced from below.
What does the dermis contain?
Blood vessels
Nerves
Glands
Hair follicles
What are the two sublayers of the dermis?
Papillary layer and Reticular Layer.
What are the characteristics of the papillary layer?
Areolar CT
Vascular
Has projections in to the epidermis called dermal papillae.
In thick skin, these form dermal ridges = fingerprints that improve grip
What are the characteristics of the reticular layer?
Makes up most of the dermis and has dense irregular CT.
What is the hypodermis?
It is the subcutaneous layer and it has superficial fascia (CT layers that surround and support organs) and as well as adipose CT below the skin. Stores half the body’s adipose tissue (for insulation)
Hypodermis is not part of the skin.
What are the differences between thin and thick skin?
Thin skin does not have a lucidum and has hair follicles, sebaceous glands, arrector pili muscles.
Thick skin is only found on the palm and the soles. Lucidum is visible and has no hair follicles, sebaceous glands or arrector pili muscles.