Integumentary Flashcards
What skin layer
Epidermis
What skin layer
Dermis
What layer
Hypodermis
What specific skin layer
Stratum corneum
What specific skin layer
Stratum lucidum
ONLY found in thick skin
Layer is translucent (Lucidum means “light”)
What specific skin layer
Stratum granulosum
Cells have stopped dividing and flatten out
Nuclei and other organelles degenerate
What specific skin layer
Stratum spinosum
Held together by desmosomes
Dendritic cells (Langerhans cells) found in this layer
What specific skin layer
Stratum basale
Attached to underlying basement membrane
Basal cells = Stem cells continually divide to replace keratinocytes lost a surface
Merkel cells
Melanocytes
What specific structure
Tactile (Meissner’s) corpuscle
aka Merkel cells
Respond to light touch
More numerous in fingertips, lips, face, and external genitalia
What specific structure
Lamellated (Pacinian) corpuscle
(can use either word)
Senses pressure and vibration
What specific structure
Bare nerve endings (sensory)
What specific structure
Nerve endings (motor)
What specific structure
Arrector pili muscle
When muscle contracts, it causes goose bumps known as Piloerection
What specific structures
Capillaries
What specific structure
Merocrine (eccrine) sweat gland
Found all over the skin
What specific structure
Apocrine sweat gland
Only found in certain locations including axillae, anal area, and the areolae (darkened area around the nipples)
Releases the secretion onto hair follicles
What specific structure
Sebaceous gland (oil gland)
Apocrine sweat gland
Empties secretion into hair follicle (can empty out of small pore instead)
Not found on palms or soles of feet
Uses holocrine secretion
What specific structure
Hair follicle
The hair root is embedded in the hair follicle
What specific structure
Hair shaft (of hair) [above/outside the skin]
Made up of dead keratinized cells
[Hair root is the hair shaft still in/below the skin]
What specific structure
Hair bulb (of hair follicle)
What specific layer
Connective tissue sheath (of follicle) (AKA dermal root sheath)
What specific layer
Glassy membrane (of follicle); basement membrane; separates external root sheath from dermal root sheath
What specific layer
External root sheath (of follicle) (outer layer of epithelial root sheath)
What specific layer
Internal root sheath (of follicle) (inner layer of epithelial root sheath)
What specific layer
Cuticle (of hair)
Outer most layer of hair shaft
What specific layer
Cortex (of hair)
Under the cuticle layer cells of hair shaft
What specific layer
Medulla (of hair)
Center most layer of cells of hair shaft
What specific structure
Hair papilla (provides nutrients to dividing hair matrix cells)
What specific structure
Hair root nerve plexus (senses movement of hair)
What specific skin layer
Stratum corneum
What specific skin layer
Stratum lucidum (found only in thick skin)
What specific skin layer
Stratum granulosum
What specific skin layer
Stratum spinosum
What specific skin layer
Stratum basale
What cell type
Melanocyte
What cell type
Merkel cell
What skin layer
Epidermis
What skin layer
Dermis
What specific skin layer
Papillary layer (of dermis)
What specific skin layer
Reticular layer (of dermis)
Integumentary system
Composed of skin, hair, nails, various glands
Epidermis made up of what cells
Stratified squamous epithelium
Dermis made up of what cells
Connective tissue (adipose, areolar, dense irregular)
Stratum basale has what specific cells
AKA Stratum germinativum
Deepest layer of epidermis
Important cells:
- Basal cells – stem cells
- Merkel cells – sensitive to touch
- Melanocytes – synthesize melanin
Stratum spinosum (spiny layer) has what specific cells
Several layers of keratinocytes (prickle cells)
- Connected by many desmosomes attached to protein fibers of cytoskeleton (look spiky)
Cells filled with pre-keratin filaments and melanin granules
Also contains dendritic cells (Langerhans cells)
Stratum granulosum
4-6 layers thick of keratinocytes
Cells have stopped dividing
Cells flatten out
Nuclei and other organelles degenerate
Accumulate granules
- 1 type of granules helps form keratin (from pre-keratin) in superficial layers
- First step in keratinization
Cells connected by desmosomes and tight junctions
Stratum lucidum
Flat dead cells filled with keratin
Found ONLY in thick skin
Layer is translucent
- lucidum means “light”
Stratum corneum
15-30 cell layers thick (thicker in thick skin)
Cells flattened and dead (filled with keratin)
- Called keratinized cells (cornified or horny cells)
Cells tightly connected by desmosomes
- Often shed in groups or sheets
What section name (hair)
Cuticle
Outer most layer of hair. Made from hard a single layer of keratinoxytes arranged like shingles
What section name (hair)
Cortex
Made up of hard keratin.
What section name (hair)
Medulla
Present only in thick hairs like the ones on your head
Made up of soft keratin, same type of keratin found in epidermis
Vellus hair
Thin, nonpigmented hair found over most of the body
Terminal hair
Thicker, coarser and pigmented hair
Found on the skalp and around the eyes
After puberty much of the cell us hair is replaced with terminal hair (90% in males, 35% in females)
