Quiz 1 Flashcards
Where is skin the thickest and thinnest?
.5 mm tympanic membrane
6 mm soles of feet and palms of hands
What is the integumentary system composed of?
Skin Skin Appendages (hair, nails, sebaceous (oil), and sudoriferous (sweat) glands)
What are the layers of skin?
Epidermis and dermis
-separated by basement membrane
What are some common features about the epidermis?
Avascular
Derived from embryonic ectoderm
Has a 26-42 day turnover time (every 2 months new epidermis)
What type of cells make up the epidermis?
Stratified Squamous epithelial cells (keratinocytes)
What are the 5 layers of the epidermis?
Stratum corneum Stratum lucidium Stratum Granulosum Stratum Spinosum Stratum Basale (Come Lets Get Sun Burned)
This layer of the epidermis is composed of dead keratinized cells that are thin, flat, and anucleated
Stratum Corneum
What layer of the epidermis is almost non existent in thinner skin?
Stratum Lucidum
also known as the transitional layer
Which layer of the epidermis is composed of diamond shaped cells containing proteins to help organize keratin filaments and contains active nuclei?
Stratum Granulosum
granulate proteins here
Which layer of the epidermis contains desmosomes (cell-cell junction), provides adhesion between cells and resists mechanical forces?
Stratum Spinosum
This is the inner most layer of the epidermis and contains a single layer of mitotically active cells.
Stratum Basale
How long does it take for cells to go from the stratum basal to the stratum corneum?
14 days to get to corneum
14 days to move through corneum and slough off
Which type of cells are responsible for skin pigmentation and where are they located?
Melanocytes located in the basal layer of the epidermis
What is the ratio of melanocytes to other basal cells?
1 melanocyte to 36 basal cells
What’s the difference between melanocyte and melanosome?
Melanocyte- produces melanin
Melanosome: - organelle in melanocyte that synthesizes, stores, and transports melanin
What causes the difference in skin color?
Size and number of melanosomes
Distribution of melanosomes
Activity of melanocytes
What is the BMZ?
Dermal-epidermal junction
-anchors epidermis to dermis
What layer is affected in blister formation?
Basement Membrane Zone (BMZ)
What are some general facts about the dermis?
Thickest layer of skin
Vascularized,
innervated,
Primarily populated by fibroblasts (produce collagen)
What are the 2 major proteins in the dermis and how thick is this layer?
Proteins: Collagen & Elastin
Ranges from 2-4 mm in thickness
What are the functions of the dermis?
Nutritional support Immune surveillance Wound Healing Thermal regulation Hemostasis (stores blood)
What process is mediated by angioblasts?
Vasculogenesis
What is angiogenesis?
Process of forming new vessels from preexisting vessels
What layer of skin is directly below the BMZ and what is its purpose?
Papillary dermis
-contains papillary loops that supply oxygen and nutrients to the overlying epidermis via the BMZ
How does the papillary dermis control interstitial pressure?
Contains lymphatic vessels that regulate resorption of fluid and assist in clearing the tissues of cells, lips, bacteria, proteins, and other degraded substances
What layer former the base of the dermis?
Reticular dermis - has thicker collagen fibers then the papillary dermis but there is no clear separation
How is fluid in the movement of the lymph system partially controlled in the reticular dermis?
Controlled by arterial pulsation, muscle contractions, and body movements
What is the most important portent for healing in the body and gives skin its tensile strength?
Collagen
accounts for 25% of skin’s total weight
Which protein in skin allows for recoil and prevents the skin from being permanently reshaped?
Elastin
Name some of the dermal appendages?
Hair follicles Sebaceous Glands (oil) Sudoriferous glands (sweat)
Which layer is composed of adipose tissue containing subnormal plexus of blood vessels also known as the superficial fascia?
Hypodermis
What are some of the functions of the hypodermis?
Attaches dermis to underlying structures Provides insulation for the body Ready reserve of energy Additional cushioning Adds to the mobility of the skin over underlying structures
How much blood can be stored in the integumentary system?
1/3 of total blood volume
What are some functions of the integumentary system?
Protection Immunity Thermoregulation Sensation Metabolism Communication Vitamin D Synthesis Blood Reservoir
How can the integument system protect the body?
- Tough fibroelastic tissue protects against mechanical assaults
- Prevents loss of fluids (electrolyte imbalances)
- Pigmentation provides UV radiation protection
How does the skin help with immunity?
- Langerhans Cells transport antigens (bacterial interference only, no viral protection)
- physical barrier
- Has Acidic pH (4-6.8) makes for harsh environment
What are the 2 categories of skin bacterial flora?
Resident - Bacteria normally found on a person
Transient - Bacteria not normally found and usually shed by daily hygienic practices
How does the skin help with thermoregulation?
- Outside barrier
- Circulation (dilate to dissipate heat)
- Sweating
- Releases heat by conduction, convection, radiation, and evaporation
- Constricts vessels to move blood to underlying body organs (causes goosebumps)
What are the 2 types of sweat glands?
Eccrine
Apocrine (in hair follicles, no significant role in thermoregulation)
What are some facts about Eccrine glands?
- Arise from epidermal invagination
- Found abundantly on palms and soles
- Largely under control of nervous system
- Respond to temperature differences and emotional stimulation
How does the skin’s sensation help the body?
- Protection from surrounding environment
- Assists with regulatory function (signals sweating, shivering, weight shifts,)
How does the skin function with communication?
- Body image
- Non-verbal communication
- Show emotion
- Expressions
What is the importance of Vit D and where is it synthesized?
Participates in calcium and phosphate metabolism and is important in mineralization of bone.
Synthesized in skin
When is Vit D considered and active hormone?
When its been converted to Calcitriol
What type of skin has higher Vitamin D synthesis rates?
Lightly pigmented skin has higher Vit D sythenized then darker skin
