Integumentary Flashcards
Epidermis
- superficial region
- is avascular and made of epithelial tissue (duh)
5 parts of integumentary system
- skin
- nails
- hair
- sweat glands
- sebaceous glands
Dermis
underlies epidermis
- fibrous connective tissue and vascular
Hypodermis (superficial fascia)
- deep to skin
- not part of skin but shares function
- adipose tissue
-anchors skin to underlying structure
Function of Skin (5)
protection of underlying tissues and organs
- excretion of salts and water
- maintenance of body temperature
- production of melanin
- detection of pressure and pain
Keratin
Protein produced by skin for protection, has yellow pigment
Vitamin D
synthesis of Vitamin D
Lipids
Lipids are stored in skin
What is Epidermis made of? *3 cells
- Keratinocytes
- Melanocytes
- Dendritic (Langerhans) cells
Keratinocytes (function and traits)
- produce the fiber keratin
- connected by desmosomes
- very regenerative
Melanocytes
Produce pigment melanin, which is packaged into melanosomes
Dendritic (Langerhans) cells
Star-shaped macrophages that patrol deep epidermis and activate immune system
Tactile (Merkell) Cells
Sensory receptors that sense touch
Melanosomes
are transferred to keratinocytes, where they protect nucleus from UV damage
How many layers does the epidermis have?
- 4 or 5 (when thicker skin is needed for protection)
What are the five layers of the skin?
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum
Stratum corneum
Which layer is only in thick skin?
Stratum lucidum
Stratum Basale
- deepest layer
- Consists of a single row of stem cells that actively divide (mitotic)
- also has melanocytes
Stratum Spinosum (Function)
- contain desmosomes
- Allows resistance tension and pulling
- growth
Stratum granulosum
- flat layer
- Cell appearance changes -Cells flatten, nuclei and organelles disintegrate
- Keratinization begins
here
Prickle Cells
Keratinocytes in this Stratum Spinosum appear spikey, so they are called prickle cells
Stratum Lucidium
- only in thick skin and stains clear
- is superficial
Stratum Corneum
- Skin cells here are dead but provide protection and prevent water loss
Tissue type of layers in dermis
- connective tissue that hold things in place
Papillary Layer (tissue and function)
Superficial layer of areolar connective tissue consisting of loose, interlacing collagen and elastic fibers and blood vessels
- contains dermal papillae
Dermal papillae
superficial region of dermis that sends fingerlike projections up into epidermis
Function of Dermal Papillae
- ## surface area
Dermal Ridges
Collectively ridges are called friction ridges
Function of Friction Ridges
- Enhance gripping ability
- Contribute to sense of touch
- Sweat pores in ridges leave unique fingerprint pattern
Reticular Layer
- Consists of coarse, dense fibrous connective tissue
- holds things in place
Cleavage Lines
-in reticular layer
-caused by many collagen fibers running parallel to skin surface
-Externally invisible
- imp to surgeons because incisions parallel to cleavage lines heal more readily
Flexure Lines
- Dermis is tightly secured to deeper structures
- Skin’s inability to slide easily for joint movement causes deep creases
- Visible on hands, wrists, fingers, soles, toes
Medical Name for Stretch Marks
Striae
Three Pigments
- Melanin
- Carotene
Freckle/Mole
accumulation of melanin
Carotene
- yellow to orange pigment
- accumulates in stratum corneum
Hemogoblin
- pinkish hue of skin
- lighter skin allows pink to show
Cyanosis
- blue
- lower oxygenation of hemoglobin
Pallor
-pale color
- fear, low bp, anemia
Erythema
- fever
- hypertension
- red color
Jaundice
- yellow cast because of liver disorders
Hair
dead hard keratinized cells
4 functions of Hair
-Warn of insects on skin
-Hair on head guards against physical trauma
-Protect from heat loss
-Shield skin from sunlight
Hard Kertatin vs Soft Keratin
Hard keratin is tougher and more durable, and cells do not flake off
Shaft
area that extends above scalp, where keratinization is complete
Root
area within scalp, where keratinization is still going on
3 parts of hair shaft
- Medulla
- Cortex
- Cuticle