Brainscape's Knowledge GenomeTM

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


See full index

BMS 100 Test 2 > Fundamental physiologic basis of the dermatologic exam > Flashcards

Fundamental physiologic basis of the dermatologic exam Flashcards

1
Q

How many layers are in the skin and what are they called?

A

3; Epidermis, Dermis, Subcutaneous

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

How thick is the epidermis in the palms and soles of the feet?

A

0.4-1.4mm thick

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

How thick is the epidermis everywhere else on the body except for the palms and soles of the feet?

A

0.075-0.15mm

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

What is the largest and heaviest organ of the body?

A

Skin (8lb’s, 1.5-2m^2)

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

What are the epidermal layers? (from outermost to innermost)

A

-Stratum corneum
-Stratum lucidum (only in thick skin)
-Stratum granulosum
-Stratum Spinosum
-Stratum basale

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

Name the epidermal layer:

Location: Most superficial layer

size: 15-30 cell layers

Function: the most important component of the barrier. (prevents penetration of microbes & dehydration, and mechanical protection)

Skin cells are dead, and full of keratin and filaggrin (tight junctions, desmosomes)(filaggrin helps keratin aggregate into large microfibrils)

A

Stratum Corneum

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

Name the epidermal layer:

Location: Immediately below corneum

Size: 3-5 cell layers

Function: protection

-Cells are dead here

A

Stratum Lucidum

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

Name the epidermal layer:

Location: between the s. corneum & s. spinosum

Size: 3-5 layers (compacted & flattened)

Function:
-Living cells that are re-organizing keratin and associating it with filaggrin & other proteins

-Lamellar granules, lipid-rich layered granules that help reduce water loss

A

Stratum Granulosum

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

Name the epidermal layer:

Location: superficial to the s. basale

Size: 8-10 layers (thickest layer in most skin) & very thick in thick skin

Function:
-Very busy synthesizing keratin, proto-filaggrin, & other proteins

-Eventually, keratin becomes 50% of the cell mass of keratinocytes

-Thick bundles of keratin called tonofibrils are linked to desmosomes.

A

Stratum Spinosum

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

Name the epidermal layer:

Location: deepest epidermal layer

Size: single layer

Function:
-Stem cells divide and give rise to all of the layers

-Melanocytes: synthesize and distribute melanin to keratinocytes

-Wide range of sensory receptors

-Resident immune cells: langerhans cells

A

Stratum Basale

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

Fibrous protein: strong, often flexible long proteins that have a relatively simple, repeating secondary structure
-hydrophobic amino acid residues -> insoluble in H2O

A

Keratin

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

alpha-helical structure with many levels of structure:

-Single: “strand” protein arranged in an alpha helix->
-Two strands coiled around each other-“coiled coil”-> two strands interact w/ each other at sites of hydrophobic amino acid residues (rich in alanine, valine, leucine, isoleucine, methionine, phenylalanine)

A

α-Keratin

α-helix-(right-handed coil)
coiled-coil-(left-handed)

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

two long chains of protofilaments

A

Protofibril

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

long chains of two coiled coils

A

Protofilament

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

four protofibrils

A

tonofribril

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

many microfibrils (filaggrin helps formation)

A

Macrofibril

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

Keratin is held together by ___________ & varying numbers of________________

A

H-bonds, disulfide bonds

(the # of disulfide bonds determine the “hardness” of keratin)

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

Hard keratin is what?

A

Just keratin with no filaggrin, phospholipids (hair,nails)

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

What are the dermal layers from outermost to innermost?

A

Papillary layer
Reticular layer

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

Name the dermal layer:

-Superficial 1/5

-Loose CT: fine elastic fibers, type III and type I collagen

-Interlocks dermis & epidermis
-Contains sensory receptors

A

Papillary layer

papilla= “fingers”

dermal papilla are vascularized

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

Name the Dermal layer:

-Dense irregular CT: Type I collagen & elastic fibers (usually thickest layer of skin-4mm)

Houses:
-hair follicles
-nerves, arteries, veins & lymphatics
-sebaceous and sudoriferous (sweat) glands
-Some adipose tissue
-Smooth muscle cells
-Some sensory receptors

A

Reticular Layer

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

Which collagen types are fibril-forming collagens?

A

I, II, & III

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

Which collagen forms 90% of the body’s collagen?

A

Type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In the dermis, what produces collagen?

A

Fibroblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where does the final assembly of collagen in the skin occur?

A

Extracellular space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What type of structure is collagen?

A

“coiled-coil”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Three collagen α-chains that are coiled around each other is called what?

A

Tropocollagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the amino acid sequence of collagen fibres?

A

Gly-X-Y

often X = proline (but not always)
often Y = hydroxyproline (but not always)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the Gly-X-Y amino acid sequence of collagen fibres.

A

Glycine -has a small R-group (fits well into tightly twisted triple helix)

Hydroxyproline & proline are “kinked”

28
Q

What is ideal for covalent cross-linking of the collagen?

A

hydroxylated proline

29
Q

What is crucial to collagen formation and cross-linking of hydroxylated a. a. s?

A

Vitamin C

30
Q

Describe collagen synthesis

A

Fibroblasts produce tropocollagen fibers that have some degree of hydroxylation and glycosylation that are secreted into the ECM

Outside of the cell, the tropocollagen molecules are assembled into fibrils and fibers. (also linked to proteoglycans & glycoproteins)

31
Q

What is a hair follicle?

A

An epidermal in-growth into the dermis (invagination) that builds a long structure formed from hard keratin = hair

32
Q

Where are the hair follicles derived from?

A

epidermis
(specialized keratinocytes)

33
Q

Are there areas of the skin completely without hair? what are they?

A

Yes.
Palms and soles
lips, genital structures (glans penis, labia minora, clitoris)

34
Q

Bulbous part at the base of the follicle

A

Hair bulb

35
Q

What supplies the capillary network to the hair follicle?

A

Dermal papilla contact the hair bulb

36
Q

Keratinocytes at the papilla are very similar to what?

A

Stratum granulosum & spinosum (hair matrix)-site of active cell division

37
Q

Where are the keratinocytes found?

A

Only found in the bulb

38
Q

what in the hair bulb transfers melanosomes to keratinocytes?

A

Melanocytes

39
Q

How many layers does the hair shaft have and what are they called?

A

3; Medulla, Cortex, Cuticle

40
Q

Histology of the hair shaft layer: Medulla

A

Lightly keratinized

41
Q

Histology of the hair shaft layer: Cuticle

A

the structure of the keratinocytes is more easily seen-Looks like “tiles” or “shingles”

42
Q

A bundle of smooth muscle cells that pull the shaft into a more erect position:

A

Arrector pili

43
Q

What innervates the arrector pili?

A

Sympathetic nervous system, found on same side as the sebaceous gland

44
Q

Very sensitive mechanoreceptors

A

Hair root plexus

-myelinated nerves
-desensitized rapidly

45
Q

What are the three phases of hair growth?

A

Anagen, Catagen, telogen

46
Q

Name the phase of hair growth:

Longer period of mitotic activity and growth

A

Anagen

47
Q

Name the phase of hair growth:

Arrested growth and regression of the hair bulb

A

Catagen

48
Q

Name the phase of hair growth:

Cellular inactivity, often-> hair shedding

A

Telogen

49
Q

What happens at the beginning of the next anagen phase?

A

epidermal stem cells produce progenitors.

-these give rise to the matrix of the new hair bulb

-stem cells are located in the outer layer of the follicle, the external root sheath, near the attachment points of the arrector pili

50
Q

-Lower most layer

-Contains loose areolar and adipose tissue

-important in stabilizing the position of the skin in relation to underlying tissues

-fat storage area, insulates against excessive heat loss

-superficial region contains vessels

A

Hypodermis/subcutaneous tissue/superficial fascia

51
Q

Red blood cells in vasculature below epidermis

A

Hemoglobin

52
Q

If deoxygenation occurs (hypoxia) then the skin looks like what?

A

“blue”-cyanosis

53
Q

Yellow pigment from plants in the diet

A

Carotene

54
Q

Pale yellow to black pigment produced by melanocytes

A

Melanin

55
Q

How do you describe a skin lesion?

A

Study chart

56
Q

Any pocket of fluid(infected or not) lined in epithelium

A

Cyst

57
Q

A pocket of purulent fluid (bigger than a pustule)- not lined by epithelium

A

Abscess

58
Q

A defect in the epidermis, down at least to dermis level, usually due to impairment of healing/re-epithelialization

A

Ulcer

59
Q

Include telangiectasias (dilated arterioles, venules that one can see with the naked eye) and hemangiomas (many different types of vessel-rich, red or violet growths)

A

Vascular lesions

60
Q

Accumulation or excess shedding of the stratum corneum -can be dry or waxy-feeling

A

Scale

61
Q

Defects in the moisture barrier (filaggrin) and/or tight junctions-> antigens “getting past” the epidermal barrier over and over-> recruitment of immune cells

repetitive episodes of itchy erythematous, edematous macular-papular rash

Distribution: Extensor surfaces, face, scalp

A

Atopic dermatitis (eczema)

Photo: early-> late

62
Q

Extremely common

Pathogenesis is not well understood: chronic inflammatory condition that appears to have an autoimmune basis

Epidermal hyperproliferation-the divide really quick

Abnormal differentiation of epidermal keratinocytes

A

Psoriasis

63
Q

Pathogenesis is not well understood:
-a disorder of skin pigmentation

-The immune system attacks the cells that produce melanin

A

Vitiligo

64
Q

-Prevalence is 0.1-0.2%
-lifetime risk of developing 1.7%
-0.7-3% of patients seen by dermatologists
-M:F = 1:1, affects any age

Pathophysiology: NK cells and cytotoxic T-cells attack the hair follicle (adaptive immune system)

20% associated with stressful events: severe infection, trauma, severe psychological stress

A

Alopecia areata

clinical features: patchy hair loss that does not scar-hair will regrow
-80-90% have only 1 patch of hair loss
-Re-growth tends to occur about 1 year later

65
Q

Prevalence-50% of men
-at least 13% of women pre-menopause, > 50% women older than 65
-Usually begins to be detectable at age 40

Pathophysiology:
-Gradual conversion of terminal hairs to vellus hairs-inherited
-Greatly dependent on androgen exposure over time in men
-Androgens may be less responsible in women

A

Androgenic Alopecia

Clinical features:
Hair loss over the crown for both sexes

-Men: posterior and lateral scalp are spared

-Women: mid-frontal hair loss, vertex/temporal regions spared; often frontal hair-line preserved
If rapid, should check for disease->androgen excess

Often larger psychosocial impact on women

66
Q

Common disorder, but no good epidemiologic studies

Nonscarring alopecia characterized by acute-subacute diffuse hair shedding

Caused by a metabolic or hormonal stress or by medications => hair loss occurs 2-3 months later

Generally, recovery is spontaneous and occurs within 6 months, unless a background of pattern alopecia is present

A chronic form with a more insidious onset and a longer duration also exists.

A

Acute Telogen Effluvium

67
Q

What does the hair pull test indicate?

A

A positive hair pull test indicates active hair shedding and can be seen in TE and in active stages of AA or different scarring alopecias

68
Q

What s the hair pull test procedure?

A

-Select 50-60 hairs and hold the bundle close to the scalp between the thumb, index finger, and long finger

-Firmly pull on the bundle using slow traction as the fingers slide down the hair shaft, avoiding a fast and forceful tug

-Location: performed at the vertex, parietal areas, and the occipital area of the scalp

-Count the pulled hairs and discard broken hairs

69
Q

What is the interpretation of the hair pull test?

A

If more than 10% of hairs are removed = Alopecia areata

If fewer than 10% are removed = normal shedding

If a test is positive in more than 1 scalp region = telogen effluvium

BMS 100 Test 2 (16 decks)

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