QUIZ 2 PART 3 Flashcards
Protection: Acts as an insulation and cushion from external damage (chemicals, UV radiation, pathogens).
Temperature Regulation: Maintains homeostasis through perspiration and heat retention.
Excretion: Through sweat, helps eliminate waste.
Vitamin D Production: Synthesized when skin is exposed to sunlight, aiding calcium absorption.
INTEGUMENTARY SYSTEM
LAYERS OF THE SKIN 3
Epidermis
Dermis
Hypodermis
The outermost layer of the skin, composed of epithelial cells.
Made up of keratinized stratified squamous epithelium.
Keratinocytes produce keratin, a tough, fibrous protein that provides resilience to the skin.
EPIDERMIS
Capable of being hard and tough
Avascular: Without blood vessels
Composed of five layers (strata)
EPIDERMIS
also known as Stratum Germinativum
Deepest layer of epidermis
Liest next to dermis
Wavy borderline with the dermis anchors the two together
Cells undergoing mitosis; Daughter cells are pushed upward to become the more superficial layers
Stratum Basale
Cells start to die and form a granular layer.
Keratinocytes produce granules of keratohyalin, contributing to the keratin layer.
More keratinocytes into this thin layer
Cells located here contain many granules
Stratum Granulosum
Cells become increasingly flatter and more keratinized
Provides strength and flexibility to the skin
Stratum Spinosum
Found only in hairless skin areas like the palms and soles.
Composed of a thick, clear layer of dead cells from deeper strata that provides additional protection.
Stratum Lucidum
Outermost layer of epidermis with shingle-like dead cells filled with keratin.
Provides a protective barrier and prevents water loss
Stratum Corneum
Pigment produced by melanocytes, which gives skin its color (ranging from yellow to brown to black).
Located primarily in the stratum basale.
Accumulates in melanosomes
Melanin
Alert and activate immune cells to a threat (bacterial or viral invasion)
Found in the stratum spinosum.
Epidermal Dendritic Cells (Langerhans Cells)
Associated with sensory nerve endings and function as touch receptors (Merkel discs)
Located in the stratum basale.
Merkel Cells
TWO REGIONS OF DERMIS
Papillary Layer (Areolar)
Reticular Layer (Dense irregular connective tissue)
Located below the epidermis, this layer consists of irregular connective tissue. It supports and nourishes the epidermis.
DERMIS
Upper dermal region; Indent the epidermis above
Contains loose connective tissue with collagen and elastic fibers.
Forms dermal papillae, which create fingerprints
Papillary layer
Houses papillary loops and receptors for pain and touch
Increases friction and enhances grip on surfaces
Papillary layer
Blood vessels, sweat and oil glands
Deeper layer of the dermis.
Composed of dense connective tissue.
Houses deeper pressure receptors like Lamellar corpuscles.
Contains structures such as sweat and oil glands.
Reticular layer
`Found in the dermis; help regulate body temperature through sweating. May appear as round structures in cross-sections of the skin.
Sweat Glands
Provides strength and structure to the skin.
Collagen
are sensitive to rapid changes in pressure or vibration. Detects deep pressure and vibrations (located in the reticular layer).
Pacinian Corpuscles:
Supply nutrients to the skin and help regulate body temperature.
Blood Vessels
Detect light touch and low-frequency vibrations (located in the papillary layer).
Meissner’s Corpuscles:
Allows the skin to return to its original shape after stretching.
Elastin
Engulf and destroy pathogens.
Phagocytes
