EXAM2_L16_17_Integument Flashcards Preview

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Flashcards in EXAM2_L16_17_Integument Deck (62):
1

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

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

2

What is hypodermis? is it part of integument?

Subcutaneous fascia- not part of integument
Integument is EPIDERMIS and DERMIS

3

Integument- 2 parts and defining layers

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

4

What type of epithelium for Epidermis and dermis?

Epidermis- keratinized stratified squamous ECs
Dermis- LCT, DiRCT

5

Dermal papillae vs epidermal rete ridges

Dermal papillae- dermis ridges protruding into epidermis
epidermal rete ridges- epidermis protruding into dermis

6

5 Layers of integument? What cells in each layer?

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

7

Basale- Name- Structure- 3 Function- dysfunction?

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

8

Spinosum

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

9

Granulosum- thickness? observation? important structural component?

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

10

Corneum

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

11

Papillary Layer- composition? Where at?

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

12

Reticular Layer- Composition? Where at?

Dermis- under papillary layer
-DiRCT- Thick Collagen Type I fibers- Thick Elastic Fibers
-Less cellular
-closely packed fiber bundles

13

EVG Stain- what highlighted? Color?
Weigert elastic stain?

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

14

Langer's Lines

collagen & elastic fibers orient in parallel lines
surgeons use these lines for faster wound healing

15

Wound healing- 4 things

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

16

2 functions of Keratinocytes?
Where are they located and why?

-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

17

Nodes of Bizzozero

Desmosomes connecting cytoplasm of keratinocytes
called Bizzozero AT LM

18

Desquamation

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

19

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

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

20

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

-keratinocytes phagocytose melanocyte processes to take up melanin granules
-Pigmentation determined by rate of melanin degredation

21

3 epidermal cancers. ABCD rule
What is happening to keratinocytes?

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

22

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

-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

23

Langerhans cells- Lectin Langerin- Birbeck granules-HIV-1
WHAT IS THIS SHIZ?

Langerhans cells express lectin Langerin
-induces formation of Birbeck granules
-BG's internalize and degrade HIV-1

24

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

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

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