Integumentary System Flashcards
What are the two main layers of the skin?
Epidermis and Dermis
What is the deepest layer of the integumentary system?
Hypodermis
What is the epidermis composed of?
keratinzed, stratified squamous epithelium
How many layers are in the epidermis?
4 or 5 depending on location in the body
What are the layers of the epidermis?
Stratum corneum
Stratum lucidum (only in thick skin)
Stratum granulosum
Stratum basale
(melanocytes)
What is the Stratum Basale (stratum germinativum)?
Lowest layer of the epidermis; is a single layer if cuboidal mitotic stem cells that give rise to keratinocytes.
10-25% are melanocytes
some tactile and epidermal dendritic cells
What layer of the epidermis forms the patterns for fingerprints?
Stratum Basale
What is the Stratum Spinosum?
The prickly layer of the skin above the stratum basale.
Has 8-10 layers of keratinocytes
Melanin granules and dendritic cells are most abundant here
What is the Stratum Granulosum?
Also known as the Granular layer, this is the third deepest layer of the epidermis.
Only has 3-5 rows of flattened cells
Cells undergo keratinization in this layer due to its distance from the dermis.
What is keratinization?
Flattening of cells and disinegration of nuclei and organelles.
What do keratohyaline granules aid in?
Cell dehydration, crosslinking keratin (intermediate) filaments, and kertanization.
What do keratohyaline granules aid in?
Cell dehydration, crosslinking keratin (intermediate) filaments, and kertanization.
What is the Stratum Lucidum?
Thin, transparent band above the stratum granulosum.
Consists of 2-3 rows of dead keratoncytes.
Clear appearance due to eledin.
What is the Stratum Corneum?
AKA the horny layer; has 20-30 cell layers of horny scales made up of dead keratinocytes.
Offers biological, chemical, and physical protection
Why is the Stratum Corneum water resistant?
Glyco protiens