Integumentary System/Skin (Q1,P3) Flashcards
1
Q
Skin
A
- The body’s largest organ
- Accounts for 7% of body weight
Divided into two distinct layers: Epidermis & Dermis
2
Q
Epidermis
A
- External Layer of the skin
- stratified squamous epithelial tissue
- Contains 4 main cell types: Kertainocytes, Melanocytes, Merkel Cells, Langerhans cells
3
Q
Dermis
A
- Second major layer of the skin
- Strong, flexible connective tissue; cells associated with any connective tissue proper
- Binds the entire body together like a stocking
- Richly supplied with blood vessels and nerves
- Has two layers: Papillary Layer, Reticular Layer
4
Q
Hypodermis
A
lies deep to the dermis and is not considered part of the skin
- also called superficial fascia and the subcutaneous layer.
- Contains areolar and adipose connective tissues; adipose tissue predominates.
- Stores Fat
- Anchors skin to underlying structures
- Helps insulate the body
5
Q
Functions of the Skin
A
- Cushions and insulates deeper organs
- Protects body from bumps, scrapes, and cuts
- Protects body from chemicals, heat, and cold
- Acts as a mini-excretory system
- Screens out UV rays from the sun
- Contains sensory receptors associated with nerve endings
6
Q
Keratinocytes
A
- Cell type of the Epidermis
- most abundant
- Arise from deepest layer of epidermis
- Produce keratin – a tough fibrous protein
- Produce antibiotics and enzymes
- Keratinocytes are dead at skin’s surface
7
Q
Melanocytes
A
- Cell type of the Epidermis
- produce melanin; a dark skin pigment.
- found in the basal layer of the epidermis
8
Q
Merkel Cells
A
- Cell type of the Epidermis
- associated with a sensory nerve ending and may serve as a receptor for touch.
- found in the basal layer of the epidermis
9
Q
Langerhans Cells
A
- Cell type of the Epidermis
- part of the immune system; use endocytosis to take up foreign proteins (antigens) that have invaded the epidermis.
- Contains star-shaped Langerhans cells
- Found in the spiny layer
10
Q
Papillary layer
A
- Layer of the dermis
- superficial layer - includes dermal papillae – 20% of thickness of the dermis – areolar connective tissue
11
Q
Reticular Layer
A
- Layer of the dermis
- deeper layer – 80% of thickness of dermis – dense irregular connective tissue
12
Q
Melanin
A
- skin color pigment
- most important pigment; ranges from yellow to reddish to brown to black
13
Q
Carotene
A
- skin color pigment
- yellowish pigment from carrots and tomatoes
14
Q
Hemoglobin
A
- skin color pigment
- Allows crimson color of oxygenated hemoglobin to show through
15
Q
Hair
A
- Appendage of the skin
- Flexible strand of dead, keratinized cells
- Made of Hard keratin – tough and durable
- 2 Chief parts of a hair
Root – imbedded in the skin
Shaft – projects above skin’s surface
