Week 2 - Integumentary System - Marisa Flashcards
(87 cards)
organs of the integumentary system include
skin and its accessory structures: hair, nails, glands, blood vessels, muscles & nerves
dermatology
medical specialty for the diagnosis and treatment of disorders of integumentary system
what is the largest organ of the body
cutaneous membrane (skin)
what is the difference between the epidermis and dermis
EPIDERMIS: outer, thinner, 5 layers. Composed of epithelial cells, is the outermost protective shield of the body. Non-vascularized; therefore nutrients reach the epidermis by diffusing through the tissue fluid from blood vessels in the dermis. DERMIS: inner, thicker, 2 layers. Makes up the bulk of the skin, is a tough, leathery layer composed mostly of fibrous connective tissue. Vascularized.
what is the layer beneath the dermis called & what is its function
Hyopdermis or subcutaneous layer. It anchors skin to the underlying tissues and organs, stores fat, acts as a shock absorber, and acts as an insulator to reduce heat loss. It also contains lamellated corpuscles which detect external pressure applied to the skin.
what is the epithelium epidermis composed of
keratinized stratified squamous epithelium. Consists of 4 distinct cell types and 4-5 distinct layers
what are the four types of cells in the epidermis?
- keratinocytes 2. langerhans cells (dendritic) 3. melanocytes 4. merkel cells (tactile)
what do keratinocytes produce and what is their function
- keratin; the fibrous protein that helps give the epidermis its protective proterties. 2. lamellar granules; release water and acts as a repellant or sealant
keratinocytes
tightly connected to one another by desmosomes, arise in the deepest part of the epidermis. These cells undergo constant mitosis and are pushed upwards by the production of new cells below them, causing millions of keratinocytes to rub off every day giving us a totally new epidermis every 25 to 45 days.
what do melanocytes produce and what is their function
melanin; protects against UV radiation
90% of epidermis cells are
keratinocytes
what is another name for langerhans cells and why
dendritic cells or intraedpidermal macrophage cells.They arise from bone marrow and migrate to the epidermis where they ingest foreign substances and are key activators of our immune system
what is another name for merkel cells and what is their function
tactile epithelial cells; every tactile cell is intimately associated with a disclike sensory nerve ending and therefore functions as a sensory receptor for touch
how many layers compose the epidermis
5; 4 thin skin layers and 1 thick skin layer
the layer of thick skin of the epidermis is called
stratum lucidum; ie: tinger tips, palms, soles of feet
what is the layer of the epidermis that is composed mostly of keratinocytes
stratum spinosum
what is the layer of the epidermis that includes keratohyalin and lamellar granules
stratum granulosum
what is the epidermis layer where cell division occurs & therefore produces all other layers
stratum basale aka stratum germinativum
what is the most superficial layer of the epidermis
stratum corneum
what is the deepest epidermis layer
stratum basale aka stratum germinatiuvum
what is the stratum corneum composed of
many flat sublayers of dead keratinocytes called corneocytes or squames
corneum means
dead skin cells
how is a callus formed
through constant friction of the stratum corneum
list the order of the epidermis layers from superficial to deep
stratum corneum, startum lucidum (only on thick skin), stratum granulosum, stratum spinosum, stratum basale