Integument Flashcards
Downward growth of epidermis along crest describes what epidermal ridge?
Interpapillary peg
Formed during 3rd to 4th months of fetal life, related to fingerprints, and subdivided into two secondary dermal ridges describes what epidermal ridge?
Primary dermal ridge
Occur in double rows, branched and thin collagenous, reticular, and elastic fibers describes what dermal ridge?
Secondary dermal ridge
Upward projections from each secondary dermal ridge describes what epidermal ridge?
Dermal papillae
Stratified squamous epithelium is derived from what embryonic layer?
Ectoderm
What are the layers of the epidermis from deepest to most superficial
- Stratum basale/germinativum,
- stratum spinosum,
- stratum granulosum,
- stratum lucidum,
- stratum corneum
Columnar to high cuboidal keratinocytes are found in what epidermis layer?
Stratum basale/germinativum
Prickle cells, developing keratohyalin, tonofibrils, and membrane-coating granules first appearing in this epidermis layer
Stratum spinosum
What forms intercellular bridges?
Tonofibrils
Flattened nucleated keratinocytes, keratohyalin aggregates, lamellar bodies, and tonofilaments are found in what epidermis layer?
Stratum granulosum
Contains eleiden, only found in thick skin, and flat keratinocytes lacking nuclei and organelles are found in what epidermis layer?
Stratum lucidum
Enucleated, flattend, dead keratinocytes; cytoplasm replaced by keratin, and multilayered describe what epidermis layer?
Stratum corneum
The dermis is derived from what embryonic layer?
Mesoderm
What kind of CT is found in the dermis?
Dense fibrous irregular CT layer beneath epidermis
What kind of CT is in the hypodermis?
Loose CT that underlies dermis
T/F: the dermis may contain fat cells that can form a thick layer called the panniculus adiposus?
False; the hypodermis
What are the dermis two layers?
Papillary layer (closest to epidermis) and reticular layer
Langerhans cells aka
Dendritic cells
Langerhans cells are derived from
Monocytes
Langerhan cells are primarily found in what epidermis layer?
Stratum spinosum
T/F: langerhan cells are antigen-presenting cells
True
Birbeck granules are characteristic of what type of cells
Langerhan cells
T/F: langerhan cells migrate from epidermis to lymph nodes
True
Merkel cells are what type of sensory receptors?
Mechanoreceptors
Merkel cells are usually found in what epidermis layer?
Stratum germinativum
Merkel cells contain what type of granules?
Catecholamine-like granules
Merkel cells can diffuse what type of cells?
Neuroendocrine cells
Melanocytes are derived from what kind of cell?
Melanoblasts
Melanocytes inject what into keratinocytes?
Inject melanin granules
For the pathway for melanin formation, it requires what enzyme?
Tyrosinase
Epidermis starts as a single layer of ectodermal cells that DIVIDE DURING THE SIXTH WEEK TO FORM:
Periderm and inner cuboidal germinal layer
Sebaceous glands release sebum into what structure?
The hair follicle
Sebaceous glands are what type of glands?
Holocrine
Sweat (sudoriferous) glands are what type of glands?
Merocrine and apocrine glands
Merocrine gland has what type of endings? (Based on neurotransmitter)
Cholinergic endings
Coiled, simple stubular secretory portions describe what type of gland?
Merocrine
This gland is found in labia majora, areola, and axillary and anal regions
Apocrine glands
What kind of innervation does apocrine glands have? (Based on neurotransmitter)
Adrenergic innervation
What are the 2 special types of apocrine glands?
Ceruminous glands and glands of Moll
Does merocrine or apocrine gland have thick, viscous secretion?
Apocrine glands
What are the components of the hair follicle (3)
Root sheaths, hair shaft, and hair bulb
What component of the hair follicle has: vascularized dermal papilla, matrix high in mitotic activity, and is the expanded lower part of hair follicle?
Hair bulb
Down growth of epidermis is found in internal or external root sheath?
External
Generated by bulb matrix and has layers is the internal of external root sheath?
Internal
What are the hair shaft layers (3)?
Medulla (innermost), cortex, and cuticle
What are the 2 signaling pathways in keratinocyte stem cells?
Wnt and Notch signaling pathway