Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MSS > Epidermis > Flashcards

Epidermis Flashcards

1
Q

functions of skin

A

maintenance of body temperature, recognition of outer environment, defense against microorganisms, protection from harmful materials in external environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

defensive functions classifications?

A

physical, thermal, immune, UV, oxidant, antimicrobial, permeability barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

epidermis derivation?

A

ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

layers of epidermis

A
  1. 5th (translucent layer, stratum lucidum) present between granular layer and cornified layer on palms and soles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

4 layers?

A

basal layer, spinous layer, granular layer, cornified layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

basal layer?

A

bottom, attached to basement membrane. contains stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

basal layer stem cell process?

A

stem cells divide into daughter + transient amplifying cell. TAC divides more before separating up into stratum spinosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

stratum spinosum contents

A

(spinous layer) contains most of keratinocytes of skin, held together by desmosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

desmosomes are?

A

Desmosomes are protein complexes that connect keratinocytes and their keratin intermediate filament network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

other things responsible for keratinocyte communication and adhesion

A

Gap junctions, adherens junctions and tight junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are keratins?

A

α-helical proteins that make up the intermediate filaments of the skin. Keratins are divided into type I (acidic) and type II (basic) keratins. they heterodimerize.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

keratin intermediate filament formation?

A

2 heterodimers form a tetramer, further organized into protofilaments then keratin intermediate filaments. Keratin intermediate filaments connect to desmosomes and hemidesmosomes to form the cytoskeleton network of the epidermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the granular layer composed of?

A

(stratum spinosum) composed of flattened keratinocytes, starting to lose their nucleus and cell organelles. named this because of keratohyaline granules and lamellar granules that are present within and secreted by the keratinocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are Keratohyalin granules?

A

filled with proteins that are important for formation of the cornified envelope, such as profilaggrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where are lamellar granules?

A

present in the upper layers of the spinous layer but not secreted until the granular layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are in lamellar granules?

A

granules contain lipids such as ceramides and cholesterol that are important in forming the lipid barrier of the cornified layer. In addition, lamellar granules contain hydrolytic enzymes that promote desquamation of the cornified layer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the cornified layer made of?

A

anucleate cells called corneocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are corneocytes made of?

A

held together by proteins (e.g. filaggrin) and lipids (e.g. ceramides) released by the keratohyalin and lamellar granules, respectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

other cells in basal layer?

A

melanocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what and where are langerhans cells found?

A

type of antigen-presenting immune cell localized to the skin. spinous layer and can be present throughout the epidermis and dermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is keratinization?

A

also called cornification. it is the process of keratinocyte migration and maturation.

22
Q

process of keratinization?

A
  1. differentiation of the stem cell into a keratinocyte and separation from the basement membrane. 2. As the keratinocyte migrates to the skin surface, it flattens out and loses its water content. Lamellar granules and keratohyaline granules start to form. 3. keratinocyte progressively loses its cellular organelles and nucleus, and releases its intracellular granules. 4. The keratinocyte becomes an anucleate corneocyte within the cornified envelope and is eventually shed in the process of desquamation
23
Q

transit time of a keratinocyte through the epidermis

A

28 days

24
Q

days to migrate from the basal layer to the granular layer?

A

14

25
Q

corneocyte spends how many days in the cornified layer before desquamating?

A

14

26
Q

what is the cornified envelope made of?

A

corneocytes, proteins and lipids

27
Q

what is the protein envelope made of?

A

filaggrin, which is processed from profilaggrin, and involucrin. other proteins include periplakin and envoplakin

28
Q

what is lipid envelope made of?

A

ceramide. other lipids include free fatty acids and sterols

29
Q

what is pemphigus vulgaris?

A

autoimmune blistering disease. It is a rare disease, affecting mainly elderly people of all races and both sexes

30
Q

what is the cause of pemphigus vulgaris?

A

autoantibodies against desmosomal proteins, specifically desmoglein 1 and 3. get weakened desmosomes, intraepidermal blistering occurs.

31
Q

symptoms of pemphigus vulgaris?

A

flaccid blisters that quickly turn into erosions. can affect mucosal sites such as the mouth, nose, and genitalia, as well as any cutaneous site on the body. It can be fatal, especially when not treated

32
Q

treatment of pemphigus vulgaris?

A

flaccid blisters that quickly turn into erosions. Pemphigus vulgaris can affect mucosal sites such as the mouth, nose, and genitalia, as well as any cutaneous site on the body. It can be fatal, especially when not treated

33
Q

Ichthyosis vulgaris is?

A

common autosomal dominant genetic condition with widely variable expression.

34
Q

Ichthyosis vulgaris is caused by?

A

mutations in the profilaggrin gene that lead to a defective cornified envelope

35
Q

symptoms of ichthyosis vulgaris?

A

large scales on the body. The extremities, primarily the shins, are preferentially affected. Patients have extremely dry skin and hyperlinear palms.

36
Q

Ichthyosis vulgaris predisposes to and is associated with?

A

atopic dermatitis, allergic rhinitis, food allergies, and asthma

37
Q

3 groups of UV light are?

A

UVC: 200-280 nm UVB: 280-320 nm UVA: 320-400 nm

38
Q

UVC light?

A

absorbed by the ozone layer and very little of it reaches the earth’s surface

39
Q

UVB light?

A

penetrates the epidermis and superficial dermis of the skin

40
Q

UVA light?

A

makes up most of the sun’s radiation that reaches the earth’s surface and penetrates into the dermis

41
Q

primarily responsible for erythema and sunburn?

A

UVB

42
Q

tanning and photoaging?

A

UVA

43
Q

UV light = carcinogen promoting?

A

skin cancers such as basal cell carcinoma, squamous cell carcinoma, and melanoma

44
Q

role for UV phototherapy?

A

used to treat many skin diseases such as psoriasis, atopic dermatitis, and mycosis fungoides

45
Q

sunscreen contains?

A

physical blockers or chemical blockers

46
Q

chemical blockers?

A

absorb UV radiation and convert it into heat. ex: PABA, avobenzone (Parsol 1789), oxybenzone, cinnamates, and salicylates. some are photolabile.

47
Q

SPF measures?

A

provides a measure of the protection against UVB exposure and sunburns but does not measure UVA protection.

48
Q

Minimal erythema dose is?

A

the minimum amount of UVB that causes skin redness at 24 hours

49
Q

SPF is (mathematicall)

A

ratio of the MED when protected by the sunscreen compared to the MED when unprotected (SPF = MED protected/MED unprotected)

50
Q

sunscreen criteria?

A

Patients should look for broad spectrum sunscreens that are at least SPF 30. applied at least 15 minutes prior to sun exposure so that it may properly absorb into the skin. 1 oz per adult body. Reapplication of the sunscreen every 2 hours.

MSS (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions