The Integumentary System Flashcards
What is the organ system?
Multiple organs working together for a similar function
What is an organ?
A structure made of multiple tissues performing a specific function
What is skin?
Skin is specialized epithelial membrane it has two layers epidermis & dermis.
What is the epidermis?
Epidermis is keratinized, stratified squamous epithelium
Has multiple layers of flat cells
Filled with keratin protein which makes epidermis tough & h2O proof
What are keratinocytes?
Squamous cells which make and store keratin.
90% of epidermal cells
What are melanocytes?
- Make a pigment called melanin into keratinocytes.
- Darkens skin to protect against UV radiation.
- In lower levels of epidermis 8% of epidermal cells.
What are dendritic cells (langerhans cells)?
Immune cells fight invading microbes in lower levels of epidermis
What are merkel cells(tactile cells)?
Lowest layer of epidermis interact with nerve ending for sense of touch
What is the stratum basal (base layer)?
- It is the deepest layer of the epidermis
- only one cell thick, cells divide here
- cells divide toward surface
What is the stratum spinosum?
- It is the 2nd deepest layer
- 8-10 cells thick
- Melanocytes put melanin into keratinocytes here
Keratinocytes start to make keratin
Keratinocytes at top of this layer begin to flatten & die
Stratum Grandulosum
What is the stratum lucidium?
Only on palms of the hands and the soles of the feet lighter in color that the rest of the skin
What is the stratum cornium?
The most superficial layer
The thickest layer
Vary 25-30 or more cells thick
All keratinocytes are flat, full of keratin, & dead
What is the dermis?
Deep to the epidermis
Made of dense irregular connective tissue with lots of collagen and elastic fibers
Dermis is strong & elastic
2 layers
