EXAM2_L16_17_Integument Flashcards

(62 cards)

1
Q

What are the 5 derivatives of Epidermis? Where derived from?

A

Surface Ectoderm

  1. Hair follicles,
  2. Sebaceous glands
  3. Sweat (sudoriferous) glands
  4. Nails
  5. mammary glands
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2
Q

What is hypodermis? is it part of integument?

A

Subcutaneous fascia- not part of integument

Integument is EPIDERMIS and DERMIS

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3
Q

Integument- 2 parts and defining layers

A

Epidermis- above papillary layer (BSGLC)
Dermis- between subcutaneous & Epidermis
-Contains reticular layer (glands/ducts/vessels)
and papillary layer

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4
Q

What type of epithelium for Epidermis and dermis?

A

Epidermis- keratinized stratified squamous ECs

Dermis- LCT, DiRCT

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5
Q

Dermal papillae vs epidermal rete ridges

A

Dermal papillae- dermis ridges protruding into epidermis

epidermal rete ridges- epidermis protruding into dermis

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6
Q

5 Layers of integument? What cells in each layer?

A
  1. Basale
  2. Spinosum (melanocytes, dendritic cells, keratinocyte)
  3. Granulosum
  4. Lucidum
  5. Corneum
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7
Q

Basale- Name- Structure- 3 Function- dysfunction?

A

germinativum
-single cell layer-cuboidal/low columnar/
-vitD production-Stemcells- desmosomes/hemidesmosomes
PSORIASIS- rapid proliferation of cells ~7days vs 50

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8
Q

Spinosum

A

Prickle cell layer
cuboidal to squamous
-vitD- mitotically inactive-cytoplasmic spines-
DESMOSOMES-(NODES OF BIZZOZERO)

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9
Q

Granulosum- thickness? observation? important structural component?

A

1-3 layers- squamous cell
Still retain nuclei
Keratohyalin granules (keratinization)

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10
Q

Corneum

A
squamous- variable thickness
no nucleus
keratinized cells (soft keratin)
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11
Q

Papillary Layer- composition? Where at?

A

Dermis- between basale and reticular layer
-LCT (more cellular than reticular layer)
-thin collagen fibers I and III
Thin elastic fibers

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12
Q

Reticular Layer- Composition? Where at?

A

Dermis- under papillary layer

  • DiRCT- Thick Collagen Type I fibers- Thick Elastic Fibers
  • Less cellular
  • closely packed fiber bundles
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13
Q

EVG Stain- what highlighted? Color?

Weigert elastic stain?

A

Collagen fibers- Red
Elastic fibers- Black
WES-Highlights elastic and collagen fibers

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14
Q

Langer’s Lines

A

collagen & elastic fibers orient in parallel lines

surgeons use these lines for faster wound healing

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15
Q

Wound healing- 4 things

A

Stratum basale ramps up mitosis

  1. -migration of proliferating cells
  2. -exfoliation of dead keratinocytes frees scab
  3. -fibroblasts differentiate into myofibroblasts (directed by TGF-B1)
  4. -Myofibroblasts involved in wound closure
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16
Q

2 functions of Keratinocytes?

Where are they located and why?

A

-Flaggrin & Int. Filaments (keratin filaments-tonofilaments)
1. KG’s aggregate tonofilaments into tonofibrils by releasing Flaggrin
2. Water barrier-Lamellar bodies exocytosis pro-barrier lipids,enzymes,proteases into ICS between granulosum/corneum
Keratinocytes located at Basale b/c bound by hemidesmosomes

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17
Q

Nodes of Bizzozero

A

Desmosomes connecting cytoplasm of keratinocytes

called Bizzozero AT LM

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18
Q

Desquamation

A

Exfoliation-

-result of proteolytic degradation of desmosomes in a pH dependent manner

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19
Q

Melanocytes- Derived from? Migrate from?to? What drives? What function? what don’t they have? transport?

REMEMBER THEY LOOK LIKE AN UPSIDE DOWN ORANGE OCTOPUS IN THE PICTURE

A
  • Neural Crest
  • migrate to stratum basale
  • PAX3 of dermis drives differentiation
  • No desmosomes
  • Produces melanin granules
  • Transport kinesin/dynein
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20
Q

How do MELANIN granules end up in keratinocytes? what determines integument pigmentation?

A
  • keratinocytes phagocytose melanocyte processes to take up melanin granules
  • Pigmentation determined by rate of melanin degredation
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21
Q

3 epidermal cancers. ABCD rule

What is happening to keratinocytes?

A
  1. Basal cell carcinoma
  2. Squamous cell
  3. malignant melanoma
    ABCD: asymetrical shape, border irregular, color variation, diameter >6mm
    Keratinocytes migrating into the Stratum Spinosum layer
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22
Q

Langerhan’s cells: Function? What kind of cell? where migrate from? 3 structural characteristics?

A
  • Immunocytochemistry CD1a
  • APC’s (present to T-lymphocytes)
  • migrate from marrow to spinosum
    1. indented nucleus-
    2. no desmosomes-migratory
    3. rod-shaped BIRBECK GRANULES in cytoplasm
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23
Q

Langerhans cells- Lectin Langerin- Birbeck granules-HIV-1

WHAT IS THIS SHIZ?

A

Langerhans cells express lectin Langerin

  • induces formation of Birbeck granules
  • BG’s internalize and degrade HIV-1
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24
Q

Merkel’s Cells- Where derived?- Found in what layer? in what part of body? 2 Structure details? 2 Functional details? What stain used?
Merkel cell carcinoma- rare but agressive- Sun exposure like BCC

A
Ectoderm derived
-in stratum basale
-in fingertips
-dense-cored neurosecretory granules
-desmosomes tether MC's to keratinocytes
-synapse w/ pseudounipolar neurons
-tactile sensation
Toluidine blue stain- appear lighter in color/large round nucleus
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25
What 4 cells of epidermis?
1. Keratinocytes ( 2. Melanocytes (Neural Crest) 3. Langerhan's (marrow->spinosum) APC's 4. Merkel's (ectoderm)
26
Innervation of Integument 5 types. What structural characteristic of corpuscles?
1. Free nerve endings (pain, temp, tactile) 2. Pacinian corp. (deep pressure, vibration)-ret lam. 3. Meissners corps (light touch. tactile)-derm pap. 4. Merkel's cells (tactile) 5. Ruffini's corps (tactile) Corpuscles have CT encapsulated nerve endings
27
Hair Follicle 6 parts Note: outside GM is dermis- inside is epithelium
1. Hair (medulla/cortex/cuticle) 2. IRS- int root sheath 3. ERS-ext root sheath 4. GM (glassy membrane=basal lamina) 5. CT 6. HP- hair papilla enclosed by hair bulb
28
Cortex, cuticle , hair cells (what type of cells in each)?
Cortex- cuboidal cuticle - squamous cells hair cells- hard keratin color determined by melanin content and typej
29
Stroma & Parenchyma
Stroma- supporting cells | Parenchyma-functional cells of the organ
30
APOCRINE | -Gland type? Example?
-released from apical part of cell into DUCT -Released with some Cytoplasm and PM ie- lactating mammary gland -COMPOUND TUBULOACINAR think of boobs- complicated ductwork system
31
HOLOCRINE | Gland type? Example?
-Cell debris release into duct after apoptosis ie- sebaceous glands of integument BRANCHED ACINAR
32
MEROCRINE
Exocytosis from apical end into duct ie- sweat glands of integument SIMPLE COILED TUBULAR
33
Type of secretion for each? Compound tubuloacinar Simple Branched Acinar Simple coiled Tubular
CTA-Apocrine (mucus/serous- mammary-submandibular) SBA- Holocrine- mucus into lumen (stomach) SCT- Merocrine- eccrine sweat (deep in dermis)
34
Sebaceous Glands- derived from? classification of gland? Type of secretion? What secreted? Where located?
- derived from epidermis - branched acinar - holocrine secretion of sebum (lipid + cell debris) after apoptosis. - located right next to hair shaft
35
Sweat glands- 2 types. 2 similarities?
Derived from epidermis -Simple coiled tubular -Merocrine Eccrine- ACh/Small Lumen/Sweat,ABiotic glycoproteins Apocrine-Norepinep/protein-rich stored in lumen-BIG Lumen
36
Eccrine Sweat Glands- 3 similar things to apocrine 4 things different: Innervation? product? structure?
- derived from epidermis - Simple coiled tubular - Merocrine 1. -stimulated by Sympathetic ACh 2. -Sweat & antibacterial glycoprotein granules 3. -Narrow lumen in duct 4. Three cell types
37
Apocrine Sweat Glands- 3 similar things to eccrine 5 things different: where? cell types? Innervation? product? structure?
- derived from epidermis - Simple coiled tubular - Merocrine 1. Hair follicles of Axilla, Anus, External Genitals 2. One cell type 3. Innervation by sympathetic Norepinephrine 4. Protein-rich secretion can be stored in lumen 5. WIDE lumen
38
Cell Composition of Eccrine Sweat Glands. 3 type of cells & respective compositions
1. Clear Cells (columnar, produce sweat, mitochondria, glycogen, increased surface are of PM, adjacent to intercellular canaliculi) 2. Dark Cells (pyramid, antibacterial glycoprotein granules, RER, Golgi, adjacent to lumen) 3. Myoepithelial cells (contraction to assist secretion)
39
Nail structures-
``` Free edge Nail groove Nail fold (hang nail) Lunula Nail body Eponychium (cuticle) ```
40
What part of the nail is epidermal germinative zone? What is hyponychium?
Nail matrix- Located close to the epinychium(cuticle) under the nail root Hyponychium thick epidermis attaches free edge of the nail
41
Where is Epidermis derived from? | Where is the DERMIS derived from?
Epidermis-ECTODERM Dermis- MESENCHYME from: 1. Lateral plate mesoderm (limbs/body wall) 2. Paraxial mesoderm (back) 3. Neural crest (face and neck)
42
What induces ectoderm to form the epidermis?
BMP4 and FGF
43
What allows ectoderm to form the neural plate? | Describe the BMP4 concentration gradient and why its important
Noggin, Chordin, Follistatin are expressed by the notochord and inhibits BMP4. Low BMP4 induces neural plate Intermediate BMP4 induces neural crest High BMP4 induces epidermis The concentration of BMP4 is low in the middle and increases laterally to the outside so that each layer develops correctly.
44
What two proteins induce sclerotome development? What protein induces dermatome development? What induces myotome development? What does each paraxial layer secrete respectively?
Sclerotome-SSH & Noggin >>>>[PAX1] Dermatome- NT-3 >>>>> [PAX3] Myotome- WNT >>>>> [MyoD/Myf5]
45
SSH,PAX,WNT,NT
SSH-Sonic hedgehog - sclerotome>PAX1 PAX- Paired box genes- dermis WNT- Wingless-type genes- myotome>MYF5/MyoD NT-neurotrophin genes- dermatome>PAX3
46
Lines of Blaschko
1901 derm disorders saw the segmentation lines
47
What holds all the cells of the epidermis together?
desmosomes and hemidesmosomes. They change and are lost by change in pH.
48
Why don't melanocytes have desmosomes?
They migrate- keep moving through cells- at basale level
49
melanosomes -
Kinesin transport melanin granules "melanosomes" along cytoplasmic processes of melanocyte until it makes contact with a keratinocyte. Keratinocyte phagocytose melanocyte processes in order to take up the melanin granules. the granules then transported away from keratinocyte interior by dynein.
50
Cells in the stratum basale Cells in the stratum spinosum cells in the stratum granulosum
Basal- keratinocytes, melanocytes spinosum- merkel cells, langerhans granulosum-
51
If you have a problem with ACH release or cholinergic response: if you have problem with NE or adrenergic response?
produce too much sweat or not enough sweat Produce too much sweat or not enough
52
If you have someone who stinks really bad when they sweat what gland can you associate it with?
Apocrine- high protein stored in lumen- bacteria -large protein in lumen- PUBES - NE- Develop during PUBERTY * Eccrine doesn't smell b/c it has antibacterial glycoprotein granules - small antibacterial lumen-ACH-3celltypes-merocrine-coiled tubular
53
3 cells of eccrine sweat glands
Clear- make sweat->intercellular canaliculi>small lumen (increased mitochondria/glycogen) Dark- make antibac glycoprotein granules close to lumen (increased RER/golgi) Myoepithelial- contract for secretion
54
What embryological structure inhibits BMP4? what does it release? why important? what is the gradient?
Notochord releases noggin, chordin, follistatin inhibiting BMP4 close toward center -established gradient has low center BMP4 and increasing BMP4 away from center Important because bmp4 induces development of structures based on concentration. Low BMP4- neural plate Med- Neural crest High- Epidermis
55
what layer of epidermis would you see nodes of blizzazaro?
stratum spinosum
56
Where do you find bipolar neurons? 3 places
Nasal cavity Inner ear Retina
57
3 types of cancer of skin, frequency, seriousness
Basal Cell- most common Squamous cell- 2nd most common Malignant melanoma- not as common- Most serious
58
PSORIASIS
Normal travel time 50-60 days | rapid proliferation is about 7 days in psoriasis
59
Where vitD production? | Where mitotically active?
vitD- basale-spinosum | mitosis-basale
60
Stratum granulosum
1-3 cell layers thick Have nuclei Squamous Keratinophyalin granules give it the grainy look
61
Intermediate filament associated proteins- where are they? how do they work? what do they do? How do you identify them on TEM?
Filaggrin proteins inside Keratohyaline granules- Cause keratin tonofilaments to aggregate into tonofibrils look like black tadpoles starting to form black fiber tails
62
What creates the water barrier of the epidermis?
Lamellar bodies next to plasma membranes secrete (exocytosis) into space between Granulosum and corneum to create a barrier granulosum cells secrete the lamellar bodies and the membrane is setup just deep to the corneum layer pro-barrier lipids-lipid enzymes and proteases