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112 Cards in this Set
- Front
- Back
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epidermis comes from what developmental tissue?
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ectoderm
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dermis comes form what developmental tissue?
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mesoderm
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loss of skin can lead to drop in photoactivation of what?
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vitamin D
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Thickness/Thiness of skin is all based on what layer?
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Stratum cornified
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Name the layers of the epidermis from top to bottom.
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Stratum Corneum
-stratum lucidum (optional in thin, NOT THICK) Stratum granulosum Stratus spinosum Stratum Basale |
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Name the basic pattern of skin (top to bottom)
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epidermis
basement membrane dermis subcutis |
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consists of a single layer of cells on the basement membrane
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basal layer / stratum basale
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where are keratinocytes found?
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basement membrane
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how are keratinocytes held together?
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numerous desmosomes
hemidesmosomes |
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specialized cells found in the stratum spinosum
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keratinocytes matured
langerhans cells |
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melanocytes are limited to what layer?
cell processes of the melanocytes are found in what layer? |
basal layer
stratum spinosum |
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keratohylain granules contain ? that when activated is involved in cross0linking the cell's cytokeratin into the tough kertains of the stratum ?
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profillaggrin
corneum |
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? fuse with plasma membrane & release contents, phospholipid lamellae which re-organize extracellularly to provide waterproofing
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lamellar bodies (membrane coating granules)
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Thin interface between epidermis and reticular dermis named for the dermal papillae that extend up in between the epidermal ridges of epidermis
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papillary
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What makes up the dermis? (3 layers)
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Papillary
Reticular Subcutis (hypodermis) |
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Thickest layer made up of coarse bundles of collagen fibers with interspersed elastic fibers running in different directions.
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reticular
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subcutaneous CT that consists mainly of adipose tissue -- large blood vessels, large blood vessels are found here with terminal hair follicles and pacinian corpuscles.
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subcutis
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what gives skin its resistance to friction and tangential stress?
(5 things) |
basal layer - hemidesmosomes
spinous layer - desmesomes dermo-epidermal junction - high surface area reticular dermis - collagen and elastin subcutis - allows skin to move freely from underlying structures |
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what layer's primary function is to prevent chemical penetration and transepidermal water loss?
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stratum corneum
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dead keratinocytes become what in the stratum corneum?
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corneocytes
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describe the intact cornified envelope.
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crosslinking of cytoskeleton and plasma membrane
FILAGGRIN participates in this process |
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name the barriers/components that help prevent water loss and chemical penetration
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stratum corneum
sebaceous glands |
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what are the organelles that contain the pigment melanin in melanocytes?
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melanosomes
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from what embryonic tissue/area do melanocytes come from?
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neural crest
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do melanocytes ever regenerate?
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no. terminally differentiated
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cell processes of the melanocytes do what?
in what layer do you find the cell processes |
transfer melanin to keratinocytes
stratum spinosum |
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what cell is relatively the same for both sexes and all races?
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melanocytes
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where do melanosomes tend to accumulate in a keratinocytes?
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apical part to protect the nuclear DNA of the keratinocytes
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if there is a problem in the conversion of tyrosine to DOPA by tyrosinase, what could possibly happen?
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loss of melanin conversion
= albinoism |
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peptides that are derived from the same precursor molecule (POMC) as ACTH
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Melanocortins (melanocyte stimulating hormones MSH)
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melanocortin (MSH) binds to what receptor ? found on what cell?
binding causes what? |
MC1-R
Melanocytes Increase production of MELANIN |
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What does exposure to UV light increase?
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melanocyte proliferation
melanosome production rate of transfer to keratinocytes |
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keratinocytes of the spinous layer have ? to combat UV damage
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Antioxidant Enzymes
(catalases, peroxidases etc.) |
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What enters the epidermis to remove UV damaged cells?
Causes what cells to exit epidermis and present antigens to T cells? |
Macrophages
Langerhan Cells |
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what are characteristic features of LANGERHANS CELLS
that help process antigen for presentation |
Birbeck granules
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What adhesion molecules do T cells acquire during proliferation of memory cells? that help them exit to extranodal sites
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Cutaneous Lymphocyte Antigen
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an epidermal cell located in the Stratum Basale associated with sensory perception
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merkel cell
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postganglionic fibers from the ganglia in the paravertebral chain supply ?
efferent or afferent? |
blood vessels
sweat sebaceous glands efferent |
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afferent fibers of nerve endings innervate what 4 things?
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naked nerve endings
networks around hair follicles encapsulate nerve endings (meissner and pacinian) Merkel endings |
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what encapsulated nerve endings do tactile sensation?
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Meissner
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True or False
There are sensory receptors present in both epidermis and dermis |
TRUE
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area of sensation transmitted to a single dorsal root and its ganglion is a ?
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dermatome
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What two things determine sptatial discrimination?
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size of receptor's receptive field
density of receptors |
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dermal blood supply arrives from the ? and forms what two things?
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Subcutis
deep arterial & venous vascular plexus (rete cutaneum) superficial arterial & venous vascular plexus (rete subpapillare) |
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deep arterial & venous vascular plexus (rete cutaneum) is located at what junction?
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dermal-subcutaneous junction
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superficial arterial & venous vascular plexus (rete subpapillare) is at what junction?
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reticular-papillary junction
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speciailized A-V anastomoses in ACRAL skin especially in tips of fingers and toes. Invovled in fine-tuning of temperature regulation.
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Glomera
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bulk of thermoregulation occurs at which of the following?
artery vein/venules capillaries |
Vein and Venules
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What nerve activity is MOST important in overall control of skin blood flow?
(including over local factors) |
Sympathetic activity
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skin appendages are locally specialized ? derivatives
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epidermal
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simple coiled tubular glands.
most abundant where? least abundant where? purpose? |
eccrine (sweat glands)
soles of feet back heat stabilization by flooding skin with water for evaporation |
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what is the prime stimulus for eccrine glands?
what controls eccrine glands? |
heat
hypothalamic |
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innervation of eccrine (sweat glands) are by what type of nerve fibers?
what is the neruotransmitter used? |
UNMYELINATED sympathetic C fibers
ACh |
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where is the secretory portion of Eccrine glands?
What are the 3 cell types? |
DERMIS
clear cells dark cells myoepithelial cells |
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in eccrine glands, where/what do...
dark cells? clear cells? myoepithelial cells? |
more interior --function unkown
rests on myoepithelial cels and basement membrane. PMemb. infloding. make primary sweat which is isotonic filtrate of blood found between secretory cells and basement membrane. Help excrete sweat |
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Composition of duct portion of Eccrine glands?
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Two layers of cuboidal cells with cell junctions that allow them to function as syncytium
no myoepithelial cells absorption occurs of Na+/electrolytes making sweat hypotonic |
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large volumes of sweating can cause loss of what ion?
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K+
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apocrine sweat glands are found in what layer of tissue?
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subcutaneous tissue
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Where do apocrine sweat glands open up too?
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hair follicles
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Apocrine sweat glands contain what type of specialized epithelial cells?
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myoepithelial cells
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What type of innervation does apocrine sweat glands contain?
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sympathetic adrenergic
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What is a the pilosebaceous apparatus contain?
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hair
hair follicle arrector pili muscle sebaceous gland |
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Where sebaceous glands found? (thin skin, thick skin)
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thin skin
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sebaceous glands secrete through what type of method?
(apocrine, endocrine etc.) |
holocrine
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True or False
Sebaceous glands are an outgrowth of external root sheath of hair shaft. |
True
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What helps sebaceous glands expel their secretions?
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arrector pili muscles
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What Type of Hair?
fetal hair that are shed shortly before or after birth? |
Lanugo Hair
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What Type of Hair?
located over most of the body, short, non-pigmented, after puberty it is converted to terminal hair in the axillary and anogenital regions and over the face and trunk in males |
Vellus Hair
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What Type of Hair?
located on scalp, beard, axilla, groin & other hairy areas generally long, pigmented (including eyebrow & eyelash hairs) |
terminal hair follicles
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What Type of Hair?
located on scalp, beard, chest, back axilla, and groin; these are follicles with an atrophied hair shaft & hypertrophied sebaceous gland |
Sebaceous hair follicles
(sometimes lumped with vellus hairs) |
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The term used to describe the structural support & production portion lying beneath the skin surface
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hair foolicle
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what part of the hair follicle contains matrix cells which produce the hair shaft?
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Hair bulb
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Where are Melanocytes in the germinal layer that make melanin causing the color of the hair shaft found in the hair follicle?
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hair bulb
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What structure within the hair bulb contains capillaries and specialized fibroblasts which controls the number of matrix cells & thus hair size?
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Dermal Papilla
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True or False
The outer root sheath is continuous with the surface epidermis. Contains Melanocytes, Langerhans cells & Merkel cells -- can help in repopulate the epidermis after damage. |
True
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Where are multipotent stem cells for hair, epidermal & sebaceous gland regeneration found?
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Bulge of the outer root sheath located near the insertion of arrector pili muscle
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What determines the shape of the hair?
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Inner-Root Sheath
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True or False
Hair shaft is composed mostly of hair NONSPECIFIC keratins from matrix cells |
FALSE
they are SPECIFIC keratins |
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What are the 3 cycles of hair?
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Anagen (growth)
Catagen (involution) Telogen (rest) |
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Anagen depends on interactions between what two things?
what gives the actual molecular single? |
Follicular Epithelium
Dermal Papilla Dermal Papilla |
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What stops anagen?
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multiple different growth factors
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Describe catagen stage
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involution of follicles reflects a burst of apoptosis in follicular Keratinocytes
follicular melanocytes also undergo apoptosis & melanogenesis ceases |
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Describe Telogen stage
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result of catagen -- hair shaft is no longer firmly anchored in the follicle
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True or False
When the DERMAL PAPILLA signals FOLLICLE to enter anagen the old hair shaft is usually shed and a new shaft is formed through the anagen process |
true
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What causes the most dramatic effects in hair growth?
Where are the receptors found on? |
androgens ---
dermal papilla |
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The nail plate and nail bed are sealed by the ?
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Hyponchium
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In what type of skin is stratum lucidum present?
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Thick skin
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Mammary glands are modified ? glands
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sweat
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Describe the hierarchy of structure in the breast.
Each gland in its FUNCTIONAL state is classified as a ? gland |
Breast >> 15-20 mammary glands >> each gland/lobe >> many lobules
Compound tubuloalveolar gland |
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Each gland/lobe has its own ? that empties at the nipple
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lactiferous duct
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Name the parenchyma tissue of the mammary glands.
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ducts
terminal duct- (leads to lobular unit) alveoli |
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Name the stroma tissue of the mammary glands
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INTERlobular CT
INTRAlobular CT |
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What forms the majority of an inactive gland and are always present
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Ducts
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What composes ducts in the mammary glands?
what regulates the development of ducts? |
epithelial lining which can be secretory
myoepithelial cells Estrogen |
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What are the smallest ducts from which functional breast alveoli will develop.
What type of stroma surround the ductules? |
Terminal Duct
INTRAlobular type |
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Alveoli is derived from the outgrowths of the ?
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terminal ducts
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When are alveoli present (breasts)?
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During late stage of pregnancy and lactation
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What are alveoli composed up of?
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alveolar cells
myoepithelial cells |
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? cells are the major cells responsible for the synthesis and secretion of milk
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Alveolar
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What regulates the development of secretory alveoli in the breasts?
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Progesterone
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The stroma found between the terminal duct-lobular units
The strome found within the terminal duct-lobular units |
INTERlobular CT
INTRAlobular CT |
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Describe the composition of INTERlobular CT
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dense CT
irregular CT SPARSELY CELLULAR fibrocytes adipocytes |
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describe the composition of INTRAlobular CT
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Loose delicate CT
HIGHLY CELLULAR plasma cells lymphocytes macrophages fibroblasts |
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Which stroma of the breast is hormonally sensitive and can become edematous in the ? phase
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INTRAlobular CT
Premenstrual |
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When are terminal duct-lobular units developed?
(stage) Are there any secretory alveoli present? |
Puberty
No |
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Describe the two modes of alveolar cell secretion?
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Apocrine - lipid secretion
Merocrine - protein secretion |
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What does apocrine glands secrete in alveolar cells?
merocrine? |
lipid secretion
protein secretion |
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What are the two types of secretory products found in lactation?
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Colostrum - secreted for the first few days after birth -- HIGH ANTIBODY content
Milk - secretory product released after the colostrum phase |
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Describe the neurohormonal reflex arc of secretion and ejection of milk
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infant suckling - stimulate sensory nerves >> causes PROLACTIN from pituitary gland >> milk synthesis and secretion
also OXYTOCIN released >> causes ejection of milk due to myoepithelial cells |
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Do male breasts have Terminal Ducts-lobule units?
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NO
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What type of muscle surrounds lactiferous sinuses allowing nipple erection?
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smooth muscle
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True or False
Nipples have increased SEBACEOUS & APOCRINE glands. |
True
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