Chapter 6:The Integumentary System Flashcards
What does the integument system consist of?
Skin Accessory Organs (Hair, Nails, & Cutaneous glands)
What are the 3 layers of the skin?
- Epidermis
- Dermis
- Hypodermis
What type of tissue is the epidermis made of?
stratified squamous
What type of tissue is the dermis made of?
connective tissue
Thick Skin (3)
- on palms and soles (corresponding areas)
- has sweat glands, but no hair follicles or sebaceous glands
- has 5 layers
Thin Skin (3)
- covers the rest of the body
- has sweat glands, sebaceous glands, & hair follicles
- has 4 layers
What are the functions of the skin? (6)
- resistance to trauma & infection
- other barriers (waterproof)
- Vitamin D synthesis
- Sensation
- Thermoregulation
- Nonverbal communication
What organs help complete Vitamin D synthesis?
Skin, Liver & Kidneys
Characteristics of the epidermis? (3)
- no blood vessels
- depends on the diffusion of nutrients from underlying tissue
- contains dead cells (keratin)
What are the layers of the skin?
Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale
What cells are found in the stratum basale? (4)
keratinocytes
melanocytes
tactile cells
stem cells
Where does mitosis take place?
stratum basale & deepest cells of stratum spinosum
What happens in the stratum spinosum?
more and more keratin filaments are produced which cause the cells to flatten
Characteristics of stratum spinosum? (4)
- dendritic cells found throughout
- named after spiny appearance
- thickest layer in thin skin
- deepest cells capable of mitosis
Characteristics of stratum granulosum?
- contains coarse dark staining granules
- waterproofing layer
- 3-5 layers of keratinocytes
Characteristics of stratum lucidum? (3)
- seen only in thick skin
- cells have no nucleus or organelles
- thin translucent zone (no granulation)
Characterisitcs of stratum corneum? (2)
- 30 layers of dead keratinized cells
- resistant to abrasion, penetration, & water loss
5 types of cells found in the epidermis
- tactile cells
- melanocytes
- keratinocytes
- dendritic cells
- stem cells
Stem cells (2)
- undifferentiated cells that give rise to keratinocytes
- found in stratum basale
keratinocytes (2)
- synthesize keratin w/ greatest majority found in epidermal cells
- produced by stem cells
melanocytes (3)
- occur only in stratum basale
- synthesize pigment melanin
- branched process spread among keratinocytes
tactile (merkel) cells (2)
FEELING
- in basal layer of epidermis
- touch receptors associated w/dermal nerve fibers
dendritic cells (3)
- found in stratum spinosum & granulosum
- stand guard against toxins, microbes, etc
What does mitosis require?
abundant supply of oxygen & nutrients that are acquired from blood vessels