DERM Flashcards
(290 cards)
1
Q
what type of epithelium is the epidermis made of
A
stratified cellular (squamous)
2
Q
what is the dermis made up of
A
connective tissue
3
Q
from which germ layer does the epidermis arise from
A
the ectoderm
4
Q
from which germ layer does the dermis arise from
A
the mesoderm
5
Q
where do melanocytes arise from
A
neural crest
6
Q
what are the five layers of the skin
A
keratin layer granular layer prickle cell layer basal layer dermis
7
Q
what structures can be found in the dermis
A
sebaceous glands
arector pilli muscles
hair follicles
8
Q
where are melanocytes located
A
mainly in the basal layer of the epidermis
9
Q
what are Blaschko’s lines
A
developmental growth pattern of the skin
10
Q
which cell is most predominant in the epidermis
A
keratinocytes
11
Q
other than keratinocytes, which cell types are present in the epidermis
A
melanocytes
langerhans cells
Merkel cells
12
Q
what mechanism are in control of epidermal turnover
A
growth factors
cell death
hormones
13
Q
what shape of cells are in the basal layer
A
small cuboidal cells
14
Q
basal cells are highly metabolically active
true/false
A
true
15
Q
what shape are cells in the prickle cell layer
A
larger, polyhedral cells
16
Q
what sort of connections are present in the prickle cell layer
A
desmosomes
17
Q
how many layers of cells make up the granular layer
A
2-3 layers
18
Q
where are keratohyalin granules found and what do they contain
A
in the granular layer of the dermis
structural filaggrin and involucrin proteins
19
Q
are there nuclei present in the granular layer
A
no
20
Q
what sort of cells are found in the keratin later
A
corneocytes (overlapping non-nucleated cell remnants)
21
Q
what is the function of the keratin layer?
A
tight waterproof barrier
22
Q
where are mucosal membranes found
A
eyes, mouth, nose, GU and GI tracts
23
Q
where are langerhans cells found
A
suprabasally
24
Q
where are Merkel cells found
A
basal layer
25
what are melanocytes
pigment producing dendritic cells
26
what organelles are specific to melanocytes
melanosomes
27
what do melanocytes convert to create melanin
tyrosine
28
what are the two different types of melanin
eumelanin (brown or black)
| phaeomelainin (red/yellow)
29
how are melanosomes transferred to adjacent keratinocytes
dendrites
30
what is vitiligo
an autoimmune disease resulting in loss of melanocytes
31
what is the function of langerhans cells
antigen presenting cells
32
'racket organelle' is associated with which cell type
langerhans cell
33
what is the function of Merkel cells
mechanoreceptors
34
what are the three phases of hair growth
anagen - growing
catagen - involuting
telogen - resting/shedding
35
which hormone influence hair growth
thyroxine
| androgens
36
how long does the anagen phase last
3-7 years
37
how long does the catagen phase last
3-4 weeks
38
what is telogen effluvium
hair follicles synchronise their telogen phase around 3 months after a stress on the body (infection, childbirth)
39
what is hirsutism
male pattern hair growth in a female
40
what causes virilisation
excess androgen
41
what is the dermo-epidermal junction
the interface between the epidermis and dermis
42
what are the functions of the derma-epidermal junction
support, anchorage, adhesion, growth and differentiation of basal cells
semi-permeable membrane acting as a barrier and filter
43
what are the three layers of the dermo-epidermal junction
lamina lucida
lamina densa
sub lamina dense zone
44
what types of cells are found in the dermis
mainly fibroblasts
| macrophages, mast cells, lymphocytes, langerhans cells
45
what are the special sensory receptors present in the skin and their function
```
pacinian corpuscles (pressure)
meissners corpuscles (vibration)
```
46
how do pacinian corpuscles appear on microscopy
lil onions
47
what causes hair pigmentation
melanocytes above the dermal papilla
48
what types of glands are present in the skin
sebaceous
apocrine
eccrine
49
where are the largest sebaceous glands located?
face and chest
50
what do sebaceous glands produce
sebum
51
what are the functions of sebaceous glands
control moisture loss
| protection from fungal infection
52
where are apocrine swear glands found
axillae and perineum
53
what do apocrine glands produce
oily fluid
54
what skin structure are apocrine glands associated with
pilosebaceous unit
55
where are eccrine sweat glands found
the whole skin surface
| especially the palms, soles and axillae
56
what is the nerve supply of the eccrine glands
sympathetic cholinergic nerve supply
57
which stimuli stimulate the eccrine glands
mental
thermal
gustatory
58
what are the functions of the eccrine glands
cooling by evaporation
| moisten palms/soles to aid grip
59
what are the main functions of skin
```
barrier protection
metabolism and detoxification
thermoregulation
immune defence
communication
sensory functions
```
60
how does melanin protect the DNA in the cells' nucleus
it absorbs UV rays
61
what are some metabolic processes that occur in the skin
vitamin D metabolism
| thyroid hormone metabolism
62
what is vitamin D3 metabolised from
cholecalciferol (7-dehydrocholesterol)
63
where is vitamin D3 stored
in the liver
64
in the presence of 290-320 UV light cholecalciferol is metabolised to
hydroxycholecalciferol (vitamin D3)
65
vitamin D3 is converted to what in the kidney
1, 25-dihydroxycholecalciferol
66
thyroxine is converted to which substance in the skin
tri-iodothyronine (T3)
67
how does the skin thermoregulate
controls sweating, shivering, blood supply
68
what sensory functions odes the skin have
touch, pressure, vibration
pain and itch
heat and cold
69
what factors contribute to the skin as an immunological system include
structure (keratin layer, stratification)
cell types (immune system cells and keratinocytes)
cytokines, chemokines, eicosanoids, antimoicrobial peptides
genetics
70
what is the keratin layer also known as
the stratum corneum
71
keratinocytes can be activated by ______ and _______ to cause an immune response
UV and sensitisers
72
what role do keratinocytes play in immunological processes in the epidermis
- sense pathogens via cell surface receptors and help mediate immune response
- produce antimicrobial peptides that can directly kill pathogens
- produce cytokines and chemokines
73
what is the main resident immune cell in the epidermis
langerhans cells
74
which type of cell is characterised by the Birbeck granule
langerhans cells
75
which type of T cell are found in the epidermis
CD8+ (cytotoxic)
76
which T cells are found in the dermis
CD4+ and CD8+
77
plasmacytoid DC are found in healthy skin
| true/false
false
| they are found in diseased skin
78
what are the main routes of drugs administration involving the skin
topical
transdermal
subcutaneous
79
what is the biggest barrier to drug penetration in the skin
the stratum corneum (keratin layer)
80
what are some examples of skin commensal bacteria
staph epidermidis
corynebacterium sp. (diphtheroids)
propionibacterium sp.
81
staph aureus is coagulase....
postive
82
what effect does coagulase have
clots plasma
83
what antibiotic is used to treat staph aureus infection
fluclox fluclox fluclox
84
some strains of staph aureus produce toxins such as...
enterotoxin (food poisoning)
SSSST staphylococcal scalded skin syndrome toxin
PVL Panton Valentine Leucocidin
85
what antibiotics can be used to treat MRSA
doxycycline
co-trimoxazole
clindamycin
vancomycin
86
coagulase negative staphs may cause infection in associated with...
prosthetic material (joints, heart valves, catheters)
87
beta haemolysis
yellow, complete
88
alpha haemolysis
green, partial
89
gamma haemolysis
none
90
alpha haem. strep includes
strep pneumoniae
| strep viridans
91
non-haem strep are found where
commensal of the bowel
92
which antibiotic is used to treat group A strep
penicillin
93
treatment for necrotising fasciitis
urgent surgical debridement
94
what is tinea pedis
athletes foot
95
what virus causes chickenpox and shingles
varicella zoster virus
96
chicken pox is caused by which aspect of VZV
varicella
97
shingles is caused by which aspect of VZV
zoster
98
symptoms of chickenpox
generalised rash and fever
99
distribution of shingles
dermatomal
100
complications of chickenpox
```
bacterial infection
pneumonitis
haemorrhagic rash
scarring
encephalitis
```
101
what causes neonatal chickenpox
VZV infection in mother in late stages of pregnancy
102
shingels is more common in which patient populations
elderly
| immunocompromised
103
presentation of shingles
tingling/pain
| erythema, vesicles and crusts
104
pain lasting longer than 4 weeks of shingles is called
post herpetic neuralgia
105
shingles is associated with what type of pain
neuralgic
106
why is ophthalmic shingles more severe than other forms
it can affect the eye via the nasociliary branch of CNV1
107
which dermatome does ophthalmic shingles affect
CNV1
108
how does ramsay-hunt syndrome present
shingles causing vesicles and pain in the auditory canal and throat
109
complications of Ramsay-hunt syndrome
facial nerve paralysis
| irritation of CNVIII (deafness, tinnitus, vertigo)
110
recurrence of HSV presents as
a blistering rash on the vermillion border
111
type 1 HSV is the main cause of...
oral lesions
112
treatment for HSV/VZV
acyclovir
113
what is acyclovir
anti-viral
| analogue of guanosine
114
how does acyclovir work
it is selectively incorporated into viral DNA inhibiting replication
115
how does erythema multiforme present
target lesions
116
which infections may trigger erythema multiforme
HSV
| mycoplasma pneumoniae
117
describe the appearance of molluscum contagiosum
fleshy, firm, umbilicate, pearlescent nodules 1-2 mm in diameter
118
treatment of molluscum contagious
liquid nitrogen
119
which virus causes warts
HPV
120
which types of HPV cause warts
types 1-4
121
how can warts be treated
salicylic acid
122
how does herpangina present
blistering rash at the back of the mouth
123
what causes herpangina
enteroviruses (coxsackie/echovirus)
124
how is herpangina diagnosed
swab of lesion and stool sample for enterovirus PCR
125
what causes hand foot and mouth disease
enteroviruses, mainly coxsackie
126
what is a fatal complication of hand foot and mouth disease
pulmonary oedema
127
erythema infectiosum is also known as
slapped cheek disease
128
what casues slapped cheek disease
erythrovirus (parvovirus) B19
129
presentation of erythema infectiosum
rash on the cheeks, followed by lacy, macular appearance
130
erythema infectiosum in adults presents with
polyarthritis of small joints
131
complications of parvovirus B19 infection
spontaneous abortion
aplastic crises
chronic anaemia
132
diagnosis of erythema infectiosum
parovirus B19 IgM test
133
what is orf
a sheep virus that affects farmers
134
how does orf present
firm fleshy nodule on the hands of farmers
135
what is the presentation of primary infection of syphilis
chancre (painless ulcers at the site of infection)
136
presentation of the secondary phase of syphilis
red rash over the body, especially the palms and soles
| snail track ulcers on mucous membranes
137
tertiary infection of syphilis
CNS, CV and gummatous manifestations
138
what bacterium causes syphilis
treponema pallidum
139
diagnosis of syphilis
blood test or swab of chancre for PCR
140
treatment of syphilis
penicillin infections
141
what causes Lyme disease
borrelia burgdorferi
142
how long does a tick need to be attached to cause Lyme disease
24 hours
143
early presentation of Lyme disease
erythema migrans
144
late presentation of Lyme disease
heart block
nerve palsies
arthritis
145
treatment of Lyme disease
amoxicillin or doxycycline
146
diagnosis of Lyme disease
presence of erythema migrans
| borrelia burdorferi IgG test
147
Zika presentation
```
mild fever
rash (maculopapular)
headaches
arthralgia
myalgia
non-purulent conjunctivas
```
148
complications of Zika
microcephaly
| Guillain Barre syndrome
149
what is the ratio of melanocytes of basal cells
1:10
150
what types of collagen are present in the dermis
types I and III
151
where is the papillary dermis
just below the epidermis
152
what is found in the reticular dermis
appendage structures eg sweat glands, pilosebaceous units
153
what is the epidermal basement membrane made of
laminin and collagen IV
154
what is hyperkeratosis
increased thickness of keratin layer
155
what is parakeratosis
persistence of nuclei in the keratin layer
156
what is acanthosis
increased thickness of epithelium
157
what is papillomatosis
irregular epithelial thickening
158
what is spongiosis
oedema between shamus cells that appears to increase prominence of intercellular prickles
159
what are the 4 main inflammatory skin disease reaction patterns
spongiotic-intraepidermal oedema
psoriasiform
lichenoid-basal layer damage
vesiculobullous-blistering
160
lichenoid disorders are characterised by damage to what skin structure
basal epidermis
161
how do lichenoid disorders present
itchy flat topped violaceous papules
162
how is lichen planus described histologically
irregular sawtooth acanthosis
hypergranulosis and ortohyperkeratosis
band-like upper dermal infiltrate of lymphocytes
basal damage with formation of cymoid bodies
163
what skin disorder has the following histological appearance;
irregular sawtooth acanthosis
hypergranulosis and ortohyperkeratosis
band-like upper dermal infiltrate of lymphocytes
basal damage with formation of cymoid bodies
lichen planus
164
examples of immunobullous diseases
pemphigus
bullous pemphigoid
dermatitis herpertiformis
165
what age group is most commonly affected by pemphigus
middle age
166
how is pemphigus treated
steroids
167
what is the most common type of pemphigus
pemphigus vulgaris
168
what type of antibodies are associated with pemphigus vulgaris
IgG auto-antibodies against desmoglein-3
169
what is the function of desmoglein-3
desmosomal attachment
170
what is the pathological process causing pemphigus vulgaris
```
IgG against desmoglein-3
immune complexes form on cell surfaces
complement activation and protease release
disruption of desmosomes
acanothlysis
```
171
where does pemphigus vulgaris commonly present
scalp, face, axillae, groin and trunk
| may affect mucosa
172
how does pemphigus vulgaris present
fluid filled blisters which rupture to form shallow erosions
173
what is the pathological process causing bullous pemphigoid
```
circulating antibodies (IgG) react with a major and/or minor antigen of the hemidesmosomes anchoring basal cells to basement membrane
this result complement activation and tissue damage
```
174
how does bullous pemphigoid present
sub epidermal blisters
175
immunofluorescence appearance of bullous pemphigoid
linear IgG + complement deposited around BM
176
what autoimmune condition is dermatitis herpetiformis associated with
coeliac disease
177
presentation of dermatitis herpetiformis
symmetrical, intensely itchy lesions
| elbows, knees and buttocks often affected
178
what is the hallmark of dermatitis herpetiformis
papillary dermal micro abscesses
179
pathogenesis of acne
sebum produced by sebaceous gland plugs pilosebaceous unit
keratin and sebum build up to produce comedones (blackheads/whiteheads)
rupture causes acute inflammation and foreign body granulomas
180
presentation of rosacea
recurrent facial flushing
visible blood vessels
pustules
thickening of skin (rhinophyma)
181
factors that aggravate rosacea
sunlight
alcohol
spicy foods
stress
182
chemical mediators of itch
histamine, PGE2, acetylcholine, serotonin, kvllikrein, interleukin 2
183
what are the 4 causes of itch
pruritoceptive
neuropathic
neurogenic
psychogenic
184
what causes pruritoceptive itch
something (usually associated with inflammation or dryness) in the skin causes itch
185
what causes neuropathic itch
damage of any sort to central or peripheral nerves
186
define neurogenic itch
no evident damage in CNS but itch is caused by something acting on CNS receptors (eg opiates)
187
what causes psychogenic itch
psychological causes with no CNS damage (eg itch with delusions of infestation)
188
what is dermographism
stroking the skin causes excessive mast cell degranulation and release of histamine and other within-skin mediators resulting in a raised white mark, with surrounding erythema
189
examples of pruritoceptive itch
lichen planus, eczema, insect bites, psoriasis,
190
what types of systemic diseases are associated with itch
```
haematological
paraneoplastic
liver and bile duct
psychogenic
kidney disease
thyroid disease
```
191
what is the commonest form of psoriasis
chronic plaque psoriasis (psoriasis vulgaris)
192
what is Koebner phenomenon
psoriasis developing in an area of trauma
193
what is Auspitz sign and what is it is sign of
removal of scale surface reveals tiny bleeding point (dilated capillaries in elongated dermal papillae)
psoriasis
194
what are the 4 types of psoriasis
chronic plaque (psoriasis vulgaris)
guttate
palmoplantar pustular
erythrodermic/widespread pustular
195
nail signs of psoriasis
onycholysis (separation of nail from nail bed)
nail pitting
dystrophy
subungual hyperkeratosis
196
why do people with severe psoriasis have a life expectancy reduced by about 4 years
increased CV risk
197
topical therapies for psoriasis
```
vitamin D analogues (calcipotriol, calcitriol)
coal tar
dithranol
steroid ointments
emollients
```
198
specialist treatments for psoriasis
```
phototherapy (narrow band UVB and PUVA)
systemic treatments (immunosuppression eg methotrexate, immune modulation eg biologic agents
```
199
initial management of acne
```
oral antibiotic (doxycycline)
topical retinoid
```
200
second line acne management
oral isoretinoin (systemic retinoid)
201
side effects of isoretinoin
causes initial flare of acne for 2-3 weeks
| congenital defects
202
what is acne vulgaris
chronic inflammatory disease of the pilosebasceous unit
203
what sites are most affected by acne vulgaris
face, upper back, anterior chest
204
morphological description of acne vulgaris may include
comedones (open = blackhead, closed = whitehead)
pustules and papules
cysts
erythema
205
how does rosacea differ from acne
no comedones as there is no involvement of the pilosebaceous unit
206
what is rhinophyma
enlarged/unshapely nose
| associated with rosacea
207
topical therapy for rosacea
metronidazole
| ivermectin (reduce demodex mite)
208
oral therapy for rosacea
tetracycline long term
| isoretinoin low dose if severe
209
sites commonly affected by lichen planus
volar triste/forearms, shins and ankles
210
what is Wickham's striae and what is it a sign of
fine lace-like pattern on the surface of papules and buccal mucosa
lichen planus
211
how long does lichen planus normally last
12-18 months
212
treatment of lichen planus
topical steroids (oral steroid is extensive)
213
how to differentiate between pemphigus vulgaris and bullous pemphigoid
bullous pemphigoiD - the split is Deeper, through the DEJ
| pemphiguS - split is more Superficial, intra-epidermal
214
what is Nikolsky's sign and what is it associated with
the top layers of the skin slip away from the lower layers with slightly rubbed
pemphigus
215
is bullous pemphigoid associated with blisters
yah, blisters burst to leave erosions
216
Nikolsky's sign is positive in bullous pemphigoid
| true/false
false - the split in BP is not intra-epithelial
217
bullous diseases may initially present with urticated itchy plaques
true/false
true
218
is mucosal involvement common in bullous pemphigoid, pemphigus vulgaris or both
pemphigus
219
tense bullae are associated with...
| flaccid bullae are associated with...
```
tense = bullous pemphigoid
flaccid = pemphigus
```
220
which bullous disorder has the worse prognosis
pemphigus
221
signs of acute phase eczema
papulovesicular rash
erythema
oedema (spongiosis)
ooze or scaling and crusting
222
signs of chronic phase eczema
thickening (lichenification)
elevated plaques
increased scaling
223
how is contact allergic dermatitis investigated
patch testing
224
what is the typical distribution of atopic eczema
flexural distribution
225
what causes eczema herpeticum
HSV
226
morphology of eczema herpeticum
monomorphic punched-out lesions
227
diagnostic criteria fro atopic eczema
```
itching + 3 or more of;
visible flexural rash**
history of flexural rash**
history of atopy
dry skin
onset before 2 yo
**cheeks and extensor surfaces in infants
```
228
which gene is most significant in the development of atopic eczema
filaggrin
229
stasis eczema is secondary to
hydrostatic pressure
oedema
red cell extravasation
230
what is ash-leaf macule a sign of
tuberous sclerosis
231
what tumours are associated with tuberous sclerosis
periungual fibromas (around nails)
facial angiofibromas
hamartomas (angiomyolipomas - heart, lung, kidneys)
bone cysts
232
why is tuberous sclerosis associated with seizures
cortical tubers and/or calcification of falx cerebri
233
presentation of epidermolysis bullosa
blistering at birth
234
type of epidermolysis bullosa
simplex
junctional
dystrophic
235
result of haploinsufficiency
only one copy of working - reduced protein production
236
result of dominant negative mutation
expression of abnormal protein interferes with normal protein
237
result of gain of function mutation
mutant protein gains new function, affecting cell processes
238
result of autosomal recessive mutations
2 faulty copies of gene produce no protein
239
cafe au lait macules
neurofibromatosis type 1
240
presentation of NF1
```
cafe au lait
neurofibromas
plexiform neuroma
axillary or inguinal freckling
optic glioma
lisch nodules
bony lesions
```
241
ichthyosis vulgaris is caused by a mutation in which gene
filaggrin
242
ABCDE melanoma
```
asymmetry
borders
colour
diameter
evolution
```
243
what is the ugly duckling sign
a mole that looks different from all the others on a patients skin is more likely to be melanoma
244
describe appearance of BCC
```
pearly/translucent
slow growing lump or non-healing ulcer
visible blood vessels
central ulceration
scaly plaque
```
245
what is a morphoeic BCC
infiltrative
246
SCC presentation
hyperkeratotic (crusted lump or ulcer
fast growing
painful, bleeding
247
precursor lesions for SCC
actinic keratoses
| Bowen's disease (carcinoma-in-situ)
248
where does SCC tend to present
sun-damaged skin
249
what are actinic keratoses
precancerous skin lesions
250
risk factors for skin cancer
```
sun exposure
genetic predisposition
immunosuppression
(HPV infection)
environmental carcinogen
```
251
what is Gorlin's syndrome
nevoid basal cell carcinoma syndrome
| presents with early onset/multiple BCCs, palmar pits, jaw cysts and ectopic calcification falx
252
what are melanocyte precursor cells called
melanoblasts
253
when do melanblasts become melanocytes
when they settle in the skin
254
what sort of melanin causes red hair
phaeomelanin
255
which gene determines skin pigment and hair colour
melanocortin 1 receptor gene
256
what is the function of the MC1R gene
turns phaeomelanin into eumelanin
257
what is the science name for freckles
ephilides
258
what are actinic/solar lentigenes
liver/age spots
259
what causes actinic lentigenes
increased melanin and basal melanocytes
| epidermis elongated rete ridges
260
what are the two types of dysplastic naevi
sporadic
| familial
261
presentation of sporadic dysplastic naevi
one to several atypical naevi
262
presentation of familial dysplastic naevi
strong FH of melanoma
| lots of atypical naevi
263
how does familial dysplastic naevi affect risk of MM
lifetime risk of melanoma up to 100%
264
what are halo naevi
naevi with a peripheral halo of depigmentation
265
what are blue naevi made up of
pigment rich dendritic spindle cells
266
where are blue naevi found
dermis
267
what colour are spitz naevi
pink
| due to prominent vasculature
268
what are the four main types of malignant melanoma
superficial spreading
acral/mucosal lentiginous
lentigo maligna
nodular
269
melanomas in which growth phase can metastasise
vertical growth phase
270
how does the growth of nodular melanoma differ from the other types
there is no evidence of radial growth phase
271
how is melanoma prognosis measured
Breslow depth
272
melanoma poor prognostic factors
```
ulceration
high mitotic rate
lymphovascular invasion
satellites
sentinel lymph node involvement
```
273
treatment of melanoma
primary excision to give clear margins
274
treatment if melanoma with positive sentinel nodes
primary excision + regional lymphadenectomy
275
treatment of melanoma with mets
chemo, immunotherapy, genetic therapies
276
what is seborrhoeic keratosis
benign proliferation of epidermal keratinocytes
277
were are seborrhoeic keratoses most common
on the face and trunk
278
what is Leser-Trelat sign
eruptive appearance of many seborrhoeic keratoses that may indicate internal malignancy
279
presentation of Bowen's disease
scaly patch/plaque
irregular border
no dermal invasion
280
atypical presentations of SCC
chronic leg ulcers (stasis ulcers)
sites of burns
chronic lupus vulgaris
281
specific sites of poor prognosis for SCC
scalp, ear, nose
282
definition of chronic leg ulcer
a open lesion between the knee and ankle joint that remains unheralded for at least 4 weeks
283
swab a leg ulcer?
only if there are signs of infection - increasing pain/exudate/smell/enlarging
284
treatment of venous ulcer
4 layer compression bandaging
| leg elevation
285
indications for surgery: rash
assist in diagnosis
286
indications for surgery: tumours
assist in diagnosis
remove malignancy
remove unwanted skin growth (cosmesis)
287
types of skin disease caused by adverse reaction to amoxicillin
```
morbilliform (measles like) eruption
urticaria
angiodema
fixed drug eruption
generalised pustulosis
```
288
what is imiquimod cream used to treat?
actinic keratoses
| superficial BCC
289
treatment of precancerous skin lesions
```
cryotherapy
solaraze
5 FU
PDT
imiquimod
resurfacing
```
290
what are the 5 layers of the scalp
```
skin
connective tissue
aponeurosis
loose connective tissue
periosteum
```
