Unit 3 - Integumentary System Flashcards
Four functions of the integumentary system
- Protection
- Sensory
- Thermoregulation
- Vitamin D synthesis
Structural organization
- Integumentary system
- Skin - Epidermis & dermis
- Hypodermis - Adipose
- Stratified squamous & loose irregular connective tissue - Accessory organs
- Hair, skin, nails
5 layers of the epidermis
(bottom to top)
- Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corenum
Stratum basale
- Deepest layer
- Contains the dermal papilla
- Where new cells are made
Stratum spinosum
- Protruding spiny cells
- 8-10 layers of keratinocytes
- Contains langerhans cells
Stratum granulosum
- Grainy appearance
- Disintegrated nuclei
Stratum lucidum
- Only on thick skin
- Palms & soles
- Keratinocytes are dead
Stratum corneum
Superficial layer of the epidermis
- Dry and dead
Keratinocyte
- Makes and stores keratin
- Hardens hair, skin, and nails.
Melanocyte
Produces melanin
Hypodermis
Connects skin to bones and muscles
- Loose areolar tissue & adipose tissue
Dermis contains
- Blood - Sweat glands
- Lymph nodes - Elastin
- Nerves - Collagen
- Hair follicles
Dermis
Contains papillary and reticular layer
Epidermis
Composed of stratified squamous epithelium
Phases of hair growth
- Anagen
- Catagen
- Telogen
Anagen phase
Cells divide at the root of the hair and push up the hair shaft
- Lasts 2-7 years
Catagen phase
transition from the hair follicle’s active growth
- 2-3 weeks
Telogen phase
Hair follicle stops growing, new anagen phase begins
- 2-4 months
Pigments responsible for skin pigment
Melanin, hemoglobin, carotene
Melanin
responsible for making dark pigments in skin, hair, and eyes
Hemoglobin
Red and pink pigment
Rule of Nines: 9%
- Front & back of head
- Front & back of each arm & hand
- Chest
- Upper back
- Abdomen
- Lower back
Front and back of each leg and foot
18%
Groin
1%
