Intro to Derm Flashcards
1
Q
Skin disorders are the _____ most common reason for visiting the doctor
A
first
2
Q
Top 3 Global burden skin disease?
A
Dermatitis
Acne
Psoriasis
3
Q
Weight skin
Size
A
4 kg
2 m^2
4
Q
Where do hair follicles originate?
A
sub-cu
5
Q
5 layers of epidermis?
A
stratum corneum stratum granulosum stratum spinosum stratum lucidum stratum basalis
6
Q
filaggrin -
A
filament associated protein that binds keratin fibers in epithelial cells - found in the stratum granulosum
7
Q
desmosomes layer
A
stratum spinosum
8
Q
stem cell layer
A
stratum basalis
9
Q
cycle from SB to SC
A
28 days
10
Q
kertinohyalin granules
A
found in the stratum granulosum - contain pro-filaggrin
11
Q
Fitzpatrick skin type
hair: blond/red
eye: blue/green
skin: fair
freckles: ++
sunburn: easily
tan: minimally
A
II
12
Q
Fitzpatrick skin type
hair: blond/red
eyes: blue/grenn
skin: white
freckels: +++
sunburn: always
tan: never
A
I
13
Q
Fitzpatrick skin type
hair: brown
eyes: dark
skin: moderate brown
freckles: 0
sunburn: minimally
tan: well
A
IV
14
Q
Fitzpatrick skin type:
hair: brown
eyes: medium to dark
skin: light brown
freckles: +
sunburn: initially
tan: gradually
A
III
15
Q
Fitzpatrick skin type:
hair: dark
eyes: dark
skin: black
freckels: 0
sunurn: never
tan: always
A
VI
16
Q
Fitzpatrick skin type
hair: dark
eyes: dark
skin: dark brown
freckels: 0
sunburn: rarely
tan: dark tan
A
V
17
Q
Skin color variation due to (2)
A
type of melanin
disbtribution of melanosomes
18
Q
eumelanin
A
black to brown pigment
19
Q
pheomelanin
A
mutated melanin - yellow to red pigment
20
Q
light skin melanosome distribution -
A
clusters above nucleus
21
Q
dark skin melanosome distribution?
A
individually throughout cytoplasm
22
Q
fx
physical barrier
A
epidermis keritoncytes
23
Q
fx
light barrier
A
epidermis melanocyte
24
Q
fx
immunological barrier
A
epidermis
langerhaans cells
25
fx
| vit D synthesis?
epidermis
| keratinocytes
26
fx
| water homeostasis
epidermis
keratinocytes
adnexa
eccrine glands
27
fx
| grasp
adnexa
| nails
28
fx
| lubrication
adnex
| sebaceous glands
29
fx
| phermones
adnexa
| apocrine glands
30
fx
| thermoregulation
adnexa
eccrine glands
dermis
blood vessels
31
fx
| strength and elasticity
dermis
| fibroblasts (produce collagen and elastin)
32
fx
| sensation
dermis
| nerves
33
fx
| insulation
sub-cu
| fat
34
fx
| calorie reservoir
sub cu
| fat
35
epidermis composition
stratified squamous epithelium
36
dermis composition
underlying CT layer
papillary dermis
reticular dermis
37
papillary dermis
loose CT lies immediately under epi
38
reticular dermis
dense CT
39
Adnexal structures (5)
```
apocrine
eccrine
hair
nails
sebaceous
```
40
sub-cu composition
adipocytes
41
regional variation of skin
| thick skin is...
hairless and found on the palms and soles
42
vitD synthesis
| skin?
7-dehydroholesterol can be converted to vitD3 by UVB... but you can also ingest and absorb
43
What happens to VitD3 D2?
Converted to 25hydroxy D in liver
44
what happens to 25hydroxy D?
converted to 1,25 dihydroxy D in the kideny
45
keritinocyte fx
form barrier layer
46
kertinocyte synthesize
keratin
47
what is keratin
the major intracellular fibrous protein of the skin
48
keratinocyte cycle?
defined cylce of proliferation, differenatiation, and apoptosis (28 days)
49
melanocyte - fx and derivation
pigment producing cells arising from the neural crest
50
melanocyte location
primarily in the basal layer of the epidermis - in hair follicles
51
melanocyte - ration to keritinocyte -
1 : 10
52
how many kertinocytes does 1 melanocyte supply melanin to? via dendrites
30
53
what is melanin from
tyrosine
54
melanin is packaged into granules called
melanosomes
55
how are melanosome transferred to keratinocytes?
via dendritic processes of the melanosome
56
what does melanin do for us
protects basal keratinocytes from UV damage (DNA)
57
Absence of melanocytes is often due to?
autoimmunity causes vitiligo which cinlically consists of depigmented macules and patches
58
langerhaans cells - location
found in all epidermal layers
59
what are langerhaans cells?
dendritic cells in the epidermis derived from a bone marrow cell
60
What do langerhaans cells do?
participate in cell mediated immune reactions by processing and presenting antigens (circulate back and forth between skin and lymph nodes)
61
Stratum basalis =
basal cell layer
62
Stratum basalis - architecture
consists of single cell layer of cuboidal or columnar kertinocytes
63
_________ are the stem cells of the epidermis
basal kertinocytes - thus a site of intense prolifearation
64
hemidesmosomes
attach basal cells firmly to the basal lamina of the dermal epidermal juctnion
65
antibodies to the protein in the hemidesmosomes may cause autoimmune blistering diseases such as?
bullous pemphigoid
66
genetic defects in collagen VII cause?
dystrophic epidermolysis bullosa
67
Type VII collagen
type VII collagen fibril, composed of three identical alpha collagen chains, is restricted to the basement zone beneath stratified squamous epithelia. It functions as an anchoring fibril between the external epithelia and the underlying stroma. Mutations in this gene are associated with all forms of dystrophic epidermolysis bullosa
68
Laminin-5 genetic defects -->
Junctional epidermolysis bullosa
69
Laminin 5
Laminin, alpha 5 has been shown to interact with BCAM,[3][4] FBLN2[5] and Collagen, type VII, alpha 1.[6]
Important in hemidesmasome
70
Desmosome
attach kertinocytes to each other
71
antibodies to proteins in desmosomes may cause autoimmune blistering diseases such as
pemphigus vulgaris
72
congenital defects in keratin filaments 5 and 14 cause?
epidermolysis bullosa simplex
73
tonofilaments
protein structures (kertain filaments) that insert into the dense plaques of desmosomes on the cytoplasmic side of the plasma membrane
74
______________ has a prickly or spiny appearance due to desmosome attachment between cells
stratum spinosum
75
intercellular adhesion in the SS depends on _________-____________ interaction in the distribtuion of stress
tonofilament - desmosome
76
synthesis of involucrin and membrane coating granules begins in this layer
SS
77
Involucrin
In binding the protein loricrin, involucrin contributes to the formation of a cell envelope that protects corneocytes in the skin.
78
stratum granulosom
the cells of this layer contain different types of granules (below SS and above SL)
79
Keratinohyalin granules contain
Profilaggrin - found in SG
80
Filaggrin
cross links keratin tonofilaments and is important in the barrier function of the skin.
81
Filaggrin is mutated in dry skin conditions including (2)
ichthyosis and atopic dermatitis
82
which protein is mutated in atopic dermatitis
filaggrin
83
which protein is mutated in ichthyosis
filaggrin
84
stratum lucidum
only in thick skin
cells of this layer no longer have nuclei or organelles
above SG below SC
85
Stratum corneum
the outermost layer of the epidermis
kertinocytes have lost their nuclei and organelles and the entire cell is filled with keratin
desmosomes still connect tightly packed adjacent cells
86
papillary layer of dermis
site of
contains
site of attachment to the epidermis and necessary to its development and differentiation
contains capillary network that is blood supply for dermis
pathway for defense cells
contains meissner corpuscles which sense touch
87
reticular layer of dermis
| composition
contains extensive collagen and elastin fibers that provide strength and flexibility
88
reticular layer of dermis
| houses
houses (along with hypodermis) epidermal derivatives such as glands and hairs and plays a major role in their development and functioning
89
which layer of the skin is pathway for major blood vessels arranged specifically to facilitate thermoregulation?
reticular layer of dermis
90
which layer of the skin is the site of nerve tracts and major sensory receptors?
reticular
91
which layer of the skin are meissner corpuscles located
papillary
92
which layer of the skin are pacinian corpuscles located
reticular
| sense vibration / pressure / touch
93
meissner corpuscles
job
location
composition
detect delicate touch
are most commonly found in the dermal papillae of thick skin
consist of Schwann cells and sensory nerve terminals wrapped by fibroblasts and collagen
94
Pacinian corpuscles
job
location
composition
rapidly adapting receptors that detect change in deep pressure
found in dermis of both thin and thick skin
large structures resembling onion
the concentric layers are composed of flattened CT like cells interspersed with intercellular fluid and collagen
a single sensory nerve fiber terminates within pacinian corpuscle
95
apocrine sweat glands
| fx location
fx
specialized sweat glands located in axillary, pubic and perianal regions
produce a milky, viscid, carbohydrate rich secretion that is initally odorless; subsequent bacterial actions lead to a characteristic axillary body odor
96
when do apocrine glands fx
puberty
97
apocrine ducts empty where?
into hair follicles just above sebaceous glands
98
eccrine sweat glands
local
fx
traditional sweat glands distributed over most of the body
not found in lips, under the nails, or the glans penis, glans clitoris, or labia minoa
watery enzyme rich secretion initally isotonic becomes hypotonic as Na is reabsorbed
important for thermoregulation
99
hair
| when develop?
develops in utero with down growth of the epidermis forming a pilosebaceous unit
100
hair composition
central medulla of soft keratin and cortex of hard keratin
101
hair growth
growth period is intermittent
| 2-3 year growth followed by a rest period of several months
102
hair pigment
comes from melanocytes at the base of the hair
103
goose bumps?
due to contraction of the arrector pilli
104
sebaceous glands
oil glands which secrete sebum, a complex mixture of lipids
105
sebaceous glands develop with?
with the hair follicles and empty their secretions into the upper 1/3 of the hair follicles
106
sebaceous gland is accelerated at
puberty
107
sebum
secreted from sebaceous glands (complex mixture of lipids)
108
kertohyalin granules
found in SG
| Contain profilaggrin
109
Albinism is due to
defect in tyrosinase gene involved in melanin production
110
Vitiligo is ...
an autoimmune disorder against the melanocyte
111
vitiligo is ________ depigmentation
acquired
112
vitiligo microscopic finding
complete absence of melanocytes
113
vitiligo is commonly seen in
periorificial and acral locations
114
attachment point of basal cells to the basal lamina of the dermal - epidermal junction
hemidesmosomes
115
Antibodies to hemidesmosomes cause
bullous pemphigoid
116
bullous pemphigoid
| primary skin lesion?
tense bulla
| acquired
117
bullous pemphigoid
| pathogenesis
autoantibodies to bp 180 (collage VII) or BP230
118
Bullous pemphigoid
| pathology
supepidermal blisters
119
Epidermolysis Bullosa =
a goupd of inherited bullous disorders characterized by blister formation in response to mechanical trauma
120
Epidermolysis bullosa simplex
defect keratin 5 or 14
121
epidermolysis bullosa junctional
defect collagen XVII or laminin 5
122
Epidermolysis bullosa dystrophic
defect in collagen VII
123
Junctional EB
Genetic defects in laminin 5
clnical:
generalized onset of blisters, improves with age
124
Recessive dystrophic EB
Defects in collagen VII
clinical
extensive dystrophic scarring can produce pseudosyndactyly
flexion contractures
increased risk of SCC
Infections
125
thickest layer of epidermis
SS
126
Desmosomes
specialized structures for cells to cell adhesion
contain intracellular keratin filament 5 and 14
also contain transmembrane proteins, desmogleins and desmocollins
127
acquired antibodies to desmoglein 1 and 3?
pemphigus vulgaris
128
pemphigus vulgaris
primary lesions?
flaccid bulla
129
pemphigus vulgaris
pathogenesis
ab to desmoglein 1 and 3
130
pemphigus vulgaris
pathology
intraepidermal blisters
131
EB simplex
pathogeneis
genetic defects in keratin 5 and 14
132
EB simplex clinical
generalized onset of blisters occur at or shortly after birth - hands, feet, and extremities are the most common sites of involvement
133
Cells in this layer start to lose their nuclei
SG
134
Cells in this layer have prominent keratinohyalin granules
SG
135
Kertainohyalin granules contain
profilaggrin
136
filaggrin -->
crosslinks keratin in the formation of the cornified cell envelope
137
lamellar bodies in the SG
Excrete lipids (ceramides)
138
this layer is made up of dead and desquamating keratinocytes
stratum corneum
139
the breakdown of filaggrin forms _______________ in the stratum corneym
NMF
| Natural moisturzing factor
140
NMF levels in skin?
decline with age
141
_________________ are causd by a defective skin barrier function due to loss-of-funtion filaggrin mutations
icthyosis vulgaris
atopic dermatitis
142
Patients with filaggrin mutations have significantly reduced levels of ________________ in the stratum__________ and exhibit increased transepidermal water loss
NMF
| Corneum
143
Merkel cells
small cells in the epidermis that are associated with nerve endings. Their function has long been uncertain, but they seem to be involved in neural development and tactile sensation - recent evidence supports a role in light touch
144
flat lesions =
macule or patch
145
raise lesions =
papule / plaque / cyst / nodule
146
raised scaly lesions =
papule with scale / plaque with scale
147
fluid filled lesion
vesicle / bulla / pustule
148
redness =
erythema / erythroderma / telangiectasia
149
purpura =
ecchymoses / petechiae / palpable purpura
150
thinning or loss =
atrophy / erosion / ulcer / fissure
151
flat area of color change
macule
152
flat area of color change >1cm
patch
153
discrete solid elevated body
papule
154
solid, flat-topped elevated area of skin >1cm and broader than thick
patch
155
firm and well defined lesion / may be dermal or sub-cu
| greater than 1cm
nodule
156
excess SC
May appear as flakes or plates
color usually white or grey
scale
157
dried blood / serum / purulen exudate
may be thick or thin
color determined by type of dried fluid
crust
158
purulent exudate color
yellow-green
159
serum color
honey
160
blood color
red-balck
161
fluid filled cavity or elevation
| form below epidermis
vesicle
162
fluid filled blister
| >1cm
bulla
163
circumscribed elevation that contains pus
pustule
164
localized blanchable redness
| caused by increased blood flow
erythema
165
generlized blanchable redness
caused by increased bloodflow
may be associated with desquamation or extensive scaling
erythroderma
166
visible persistnet dilation of small superficial cutaneous blood vessels
telangiectasia
167
flat discoloration of skin or mucous membranes
due to extravasation of blood
color transitions over time and ranges from blue-black / brown-yellow / or green
ecchymoses (bruise)
168
tiny 1-2 mm pinpoint spots
resulting from tiny hemorrhages
color is red or violaceous
petechiae
169
raise and palpable discoloration
due to vascular inflammation and extravasation of RBCs (vaculitis)
color is red or violaceous
palpable purpura
170
thinning of epidermal / dermal / sub-cu tissue
atrophy
171
localized loss of epidermal or mucosal epithelium
causes can include injury or denuding of vesicle or bulla roof (Removal
erosion
172
circumscribed loss of epidermis and at leas upper dermis
ulcer
173
ulcers are further classified by (3)
depth - can extend to sub-cu / muscle / or bone
edge - can be clean / ragged / undermined
tissue at base - necrotic / purulent / or healthy granulation tissue
174
a deep linear crack or cleavage
| found in areas of thickened skin
fissure
175
scab
adherent thick dry crust
causes can include trauma / infection / or excoriating skin disease
color is black
eschar (crust)
176
following lymphatic vessels
lymphangitic
177
pertaining to a unilateral area of skin innervated by a single posterior spinal nerve
dermatomal
178
pertaining to palms and soles
palmoplantar
179
pertaining to sun exposed areas
photodistributed
180
regions where opposing skin surfaces come in contact and may cause firction
intertriginous
181
skin surface overlaying muscles that flex joints
flexural
