Chapter 5 (integumentary System) Flashcards
(47 cards)
What are the skin functions
- Protects tissue and organs from shock
- Excretes salt, water, and waste
- Maintains body temperature
- Makes vitamin D3 (steroid)
- Stores nutrients
What is vitamin D3 (a steroid) converted into?
Calcitriol
Storage of nutrients is stored where?
Lipids stored in adipocytes in dermis and subcutaneous layer.
Two major parts of the integumentary system are?
Cutaneous membrane: epidermis, dermis, hypodermis (not apart of the cutaneous membrane)
Accessories: hair, nails, and 4 types of exocrine glands
Define epidermis
(Epi means above) epithelia does not have blood vessels; and consists of stratified squamous
Define dermis
Underlying area of connective tissue; has a lot of blood vessels; consists of dense irregular. (Below epidermis)
Define hypodermis
Also called the subcutaneous layer (not part of the cutaneous membrane (below dermis)
What are accessories in the skin?
Hair, nails, and 4 types of exocrine glands
Name the skin layers
Epidermis
Dermis { papillary layer
{reticular layer
Hypodermis (subcutaneous layer)
Define Keratinocytes
Body’s most abundant epithelial cells
2 types of skin layering
- Thick skin
- Thin skin
Define thick skin and it’s layers
Has 5 layers on palms of hands and soles of feet
1. Stratum Germinativum (deepest)
2. Stratum Spinosum
3. Stratum Granulosum
4. Stratum Lucidum
5. Stratum Corneum
Define thin skin and it’s layers
Four layers cover the rest of the body
1. Stratum Germinativum (deepest)
2. Stratum Spinosum
3. Stratum Granulosum
4. Stratum Corneum
Germy, Spiny, Grandma, Likes, Corn
Germinativum
Spinosum
Granulosum
Lucidum (not in layering if thin skin)
Corneum
Define Stratum
One layer
Define Strata
Two + layers
Define Stratum Germinativum
Also called stratum basal, deepest layer and is attached to basal lamina
- about 1 cell layer thick
- basal lamina separates epithelia from connective tissue
- has epidermal ridges (which extends into dermis) increasing attachment strength
- Germinativum cells are also called basal cells and are stem cells (which can Shang into other types of skin cells)
Define melanocytes
Produces brown pigment
- found in Germinativum
Define Spinosum
Each time one stem cell divided into two daughter cells, the daughter cell is pushed from stratum Germinativum to stratum Spinosum (also called mitosis)
- has 8-10 layers of cells
- langerHans cells (involved in immune response) are found in this layer and they; 1. Defend against microorganisms that penetrate skin
2. Attach superficial skin cancers
Define Granulosum
Also called grainy layer
Strata has 3-5 layers of keratinocytes
- when cells reach this layer they have quit dividing and start to make proteins keratin. Proteins found in hair and nails.
Define Stratum Lucidum
Also called clear layer
Found only in thick skin of palms of hands and soles of feet
-cells are flattened, densely packed and filled with keratin
Define stratum Corneum
Constitutes the exposed areas of both thick and thin skin (most superficial layer)
- 15 to 30 layers of keratinized cells
- Keratinization or cornification is the formation of the protective layer of cells with keratin
- takes 15 to 30 days for cells to move from stratum Germinativum to stratum Corneum
- dead cells remain on top of stratum
- Corneum for two more weeks until pushed to skin surface and lost
Define Carotene
Is orange/yellow pigment in epidermis
- comes from carrots and squash and is converted to vitamin A (important to eyes and epithelia)
Define melanin
Is brown, yellow brown, or black pigment and is produced by melanocytes in epidermis.
- located in stratum Germinativum
- melatonin is made from AA tyrosine
- protects against UV radiation (UV damages DNA causing skin cancers)
- melanin concentrates increase in response to sunlight