Human Anatomy - The integumentary system Flashcards
The skin is our _______ organ composed of all 4 ____ types.
Largest
tissue
What are the four tissue types?
- Nervous tissue
- Muscle Tissue
- Connective Tissue
- Epithelial Tissue
The skin is divided into what two layers?
Epidermis and Dermis
What is the epidermis?
Keratinized stratified squamous epithelium
What is the dermis?
Connective tissue
Where is the hypodermis located relative to the dermis?
Deep
What constitutes the hypodermis?
Adipose tissue and connective tissue (areolar)
What are the functions of the skin?
PREAPS P - Protection R - Regulation of body temperature E - Excretion A - Absorption P - Production of vitamin D S - Sensory reception
What are the two cell types in the epidermis?
Keratinocytes and melanocytes.
Where are keratinocytes located?
Stratum spinosum
What do keratinocytes do?
Produce keratin (protection)
At the skin surface, what is the state of keratinocytes?
Dead
Where are melanocytes located?
Stratum basale
What do melanocytes do?
Manufacture and secrete melanin
What are the layers of the epidermis (superficial to deep) and which is only present in thick skin?
Stratum corneum Stratum lucidum - only in thick skin Stratum granulosum Stratum spinosum Stratum basale
What is a callus?
Thickening of the epidermis due to repeated friction.
What is a blister?
Separation of the epidermis from dermis by a fluid-filled pocket.
What is the stratum basale?
- Deepest layer of the epidermis
- Attached to underlying dermis
- Cells actively divide (single row of youngest keratinocytes)
- Also contains melanocytes
What is the stratum spinosum (spiny layer)?
- 8-10 cells layers thick
- small amount of mitosis
- contains thick bundles of intermediate filaments
- contains star-shaped Langerhans cells (macrophage)
- 2nd deepest layer
What is the stratum granulosum?
1-5 layers of flat, dying keratinocytes
- contains lamellar granules that release waterproofing glycolipid
What is the stratum lucidum?
Only appear in thick skin on palms and soles of feet
- composed of a few rows of flat, dead keratinocytes
What is the stratum corneum (horny layer)?
25-30 cell layers thick of dead keratinocytes containing only keratin
- continuously shed
- protects skin against abrasion and penetration