Brainscape's Knowledge GenomeTM

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


See full index

BRS Y1 > Week 6- Intro to Dermatology > Flashcards

Week 6- Intro to Dermatology Flashcards

1
Q

What 2 major elements does skin contain?

A

Epidermis

Dermis

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

What does the epidermis originate from?

A

The ectoderm

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

What does the dermis originate from?

A

From the mesoderm that comes into contact with the inner surface of the epidermis

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

What is the role of the mesoderm in skin?

A

It induces differentiation of epidermal structures

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

Describe the process of development of the skin

A

Epidermis forms by week 4 (single layer of cuboidal cells)
Secondary layer develops by week 5
By week 11 basal layer proliferates to form multilayered intermediate zone
Week 9-13 hair follicles develop

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

What are the 4 main cell types in the basal layer of skin?

A

Spinosum (spinous)
Granulosum (granular)
Lucidum (clear)
Corneum (horny)

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

What are skin stem cells called?

A

Melanocytes

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

Where are melanocytes derived from?

A

The neural crest

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

When do melanocytes migrate to the epidermis?

A

Week 6-8

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

Where do melanoblasts differentiate to melanocytes to replenish the stem cell supply?

A

Hair follicles

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

What receptor is involved with regulation of melanocytes? What type of receptor is it

A

Melanocortin 1 receptor (MC1R), a G protein coupled receptor

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

What agonists activate MC1R?

A

Alpha melanocyte stimulating hormone (aMSH) and adrenocorticotrophic hormone (ACTH)

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

What happens when MC1R is stimulated?

A

Melanogenic cascade is activated, eumelanin is synthesised

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

How is the synthesis of eumelanin prevented?

A

Agouti signaling protein (ASP) elicits production of pheomelanin

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

What upregulates the expression of the MC1R gene?

A

ACTH

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

How does UV lead to increased production of melanin?

A

Increases transcription factor MITF and downstream melanogenic proteins

Increases PAR2 in keratinocytes increasing uptake and distribution of melanosomes by keratinocytes

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

What do the epidermis and dermis contain?

A

Epidermis: basement membrane
Dermis: connective tissue and subcutaneous fat

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

What cell type is the epidermis composed of?

A

Keratinocytes

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

What strata of the basal layer is only present in the palms and soles?

A

Stratum lucindum

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

What strata of the basal layer has no nuclei or organelles?

A

Stratum corneum

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

What are some roles of keratins?

A

Apoptosis
Stress response
Wound healing
Cell signaling

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

Where are desmosomes found?

A

The epidermis

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

What do desmosomes do?

A

They are adhesion complexes, they anchor keratin to cell membranes and bridge adjacent keratinocytes allowing cells to withstand trauma

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

What is the role of melanocytes in the epidermis?

A

Distribute melanin pigment to keratinocytes

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

What is the role of Langerhans cells in the epidermis?

A

They are antigen presenting cells

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

What is the role of Merkel cells in the epidermis?

A

They are mechanosensory receptors

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

What other name is the basement membrane known as?

A

Dermal epidermal junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are some roles of the basement membrane?

A

Cell adhesion and cell migration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the role of the dermis?

A

Supports the ECM and provides resilience

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the 2 main layers of the dermis?

A

Papillary (superficial, comprised of loose tissue) and reticular (composed of deep dense connective tissue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the dermis made up of?

A

Proteins (collagen and elastic fibres)
Glycoproteins
Ground substance (glycosaminoglycan and proteoglycan)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the primary cell type of the dermis?

A

Fibroblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How abundant is collagen in the dermis?

A

80-85% with type I and II being most abundant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How is blood supplied to the skin?

A

Via deep and superficial vascular plexuses (do not cross into epidermis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How is skin innervated?

A

Sensory

Autonomic: cholinergic and adrenergic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What nerve fibres innervate skin?

A

Afferent fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the 2 types of afferent nerves?

A

Corpuscular- have encapsulated receptors

Free- have non encapsulated receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are Meissner’s corpuscles?

A

Encapsulated and unmyelinated mechanoreceptors that sense low level frequency at dermal papilla eg light touch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Where are Meissner’s corpuscles most concentrated?

A

Thick and hairless skin (finger pads and lips)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are Ruffini corpuscles?

A

Slow acting mechanoreceptors sensitive to skin strech

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Where are Ruffini corpuscules found?

A

Deeper in the dermis, highest density around fingernails

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are Pacinian corpuscules?

A

Encapsulated, rapidly adapting mechanoreceptors that assist with deep pressure and vibration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where are Pacinian corpuscles found?

A

Dermal papillae of hands and feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are Merkel cells?

A

Non encapsulated mechanoreceptors for light/sustained touch and pressure found directly above the basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Where are Merkel cells most abundant?

A

Fingertips as well as palms and soles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What nerve endings are for light touch and what fibre is associated with light touch?

A

Meissner, merkel and free

Abeta fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What nerve endings are for touch/pressure and what fibre is associated with touch/pressure?

A

Merkel, ruffini, pacinian, free

Abeta and Adelta fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What nerve endings are for vibration and what fibre is associated with vibration?

A

Meissner, pacinian

Abeta fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What nerve endings are for temperature and what fibre is associated with temperature?

A

Thermoreceptor

Adelta and C fibres

50
Q

What nerve endings are for pain and what fibre is associated with pain?

A

Nociceptor

Adelta and C fibres

51
Q

Around how many bacteria are found on a cm^2 of skin?

A

1 million

52
Q

What are the main organisms found in the skin microbiome?

A

Actinobacteria, firmicutes, bacteroidetes, proteobacteria

53
Q

What are some functions of skin?

A

Immunological barrier, physical barrier, thermoregulation, sensation

54
Q

What cells are involved with helping the skin be an immunological barrier and how?

A

Langerhans cells, they initiate immune response against microbial threats and contribute to immune tolerance

55
Q

What are immunological responses of Langerhans cells in the presence and absence of danger?

A

Absence: promote expansion of skin regulatory T cells (Tregs)
Presence: rapid initiation of innate antimicrobial responses (PAMP)

56
Q

Where are antibiotics in the skin derived from? Give examples

A

Derived from keratinocytes

Defensins and cathelicidins are the 2 main ones

57
Q

What substance in the skin protects against UV?

A

Melanin in basal keratinocytes

58
Q

What restricts water and protein loss from skin?

A

Stratum corneum and the cornified cell envelope

59
Q

How does the skin carry out thermoregulation?

A

Via vasoconstriction and vasodilation in vascular plexuses

60
Q

What glands in the skin have cooling effects?

A

Eccrine sweat glands

61
Q

How much of total body fat is part of the skin?

A

80%

62
Q

What hormone released from the skin regulates hunger and energy metabolism? Where specifically is it released from?

A

Leptin, released from subcutaneous fat

63
Q

What are some functions of hair?

A

Protection against external factors
Thermoregulation
Apocrine sweat

64
Q

What are the 2 types of hair and where are they found?

A

Terminal- scalp, eyebrows and eyelashes

Vellus- rest of body

65
Q

Describe the 3 stages of the hair cycle and how long they last

A

Anagen- new hair forms and grows (2-6 years)

Catagen- regressing phase (3 weeks)

Telogen- resting phase (3 months)

Then loss of old hair

66
Q

What are hair follicles known as?

A

Pilosebaceous unit

67
Q

What follicle and glands does human skin contain?

A

Pilosebaceous follicles

Sweat glands

68
Q

What is the name of the muscle that extends at an angle between the surface of the dermis and the follicle wall?

A

Arrector pili

69
Q

What glands open into the pilary canal and are associated with apocrine glands?

A

Holocrine sebaceous glands

70
Q

What are the 2 main parts of hair

A

Infundibulum- uppermost part of the follicle from opening of sebaceous gland to surface of skin

Isthmus- lower part between opening of sebaceous gland and insertion if arrector pili muscle

71
Q

Where are hair follicle stem cells found?

A

In the bulge which is located at the insertion of the arrector pili muscle

72
Q

What acts as a reserve of stem cells in hair?

A

The outer root sheath

73
Q

What is the function of the inner root sheath in hair?

A

Guides and shapes hair, has a nerve fiber and capillary loop

74
Q

What are some functions of nails?

A

Protect the underlying distal phalanx

Increase dexterity

Facilitate scratching and grooming

Counter pressure effect on pulp- important for walking and tactile sensation

75
Q

What is the main part of the nail called?

A

The nail plate

76
Q

What does the nail plate arise from?

A

The nail matrix

77
Q

What is the nail matrix connected to and how?

A

Connected to the distal phalanx by a tendon

78
Q

What is the only visible part of the nail matrix?

A

Lunula

79
Q

What is the name of the structure where the nail detaches?

A

Hyponychium

80
Q

What are the nails lined by?

A

By the lateral nail folds

81
Q

What cells is the nail made up of? How do they develop to become nail cells?

A

Nail matrix keratinocytes which become denucleated and completely fill with keratin

82
Q

What type of disorder is psoriasis?

A

A chronic, immune mediated disorder

83
Q

What is the most common manifestation of psoriasis?

A

Sharply demarcated, scaly, erythematosus plaques

84
Q

What is the most common systemic manifestation of psoriasis?

A

Psoriatic arthritis

85
Q

How does psoriasis arise?

A

Due to polygenic predisposition but also affected by environmental triggers

86
Q

What cell types are involved with the pathophysiology of psoriasis?

A

T cells
Cells involved with innate immunity
Dendritic cells
Keratinocytes

87
Q

What are common sites of involvement in psoriasis?

A 
Scalp
Elbows
Knees
Nails
Hands
Feet
Trunk (intergluteal fold)
88
Q

Describe the pathophysiology of psoriasis

A

Stressed keratinocytes release DNA/RNA
They form complexes with antimicrobial peptides
Induces cytokine production
Dermal dendritic cells (dDCs) are activated
dDCs migrate to lymph nodes
Promote Th 1/17/22
Chemokines are released
Inflammatory cells are migrate to the dermis
Release of cytokines
Keratinocytes proliferate
Psoriatic plaque forms

89
Q

What cytokines are induced to activate dermal dendritic cells

A

TNF alpha
IL-1
IFN alpha

90
Q

Why do psoriatic plaques arise?

A

Due to keratinocyte proliferation

91
Q

What are some clinical features of psoriasis?

A

Scaly erythematosus plaques in extensor distribution
Genital psoriasis
Flexural psoriasis
Palmoplantar psoriasis
Subungal hyperkeratosis (keratin builds up underneath nails)
Onchylosis (salmon pink patches on nails)
Pitting (of nails)

92
Q

What is subungal hyperkeratosis?

A

Excess keratin underneath the nail bed

93
Q

What is onchylosis?

A

Salmon pink patches on the nail

94
Q

What is pitting?

A

Small indentations on the nail

95
Q

What is erythroderma?

A

Widespread reddening of the skin associated with inflammation, can be accompanied by exfoliation

96
Q

What is guttate psoriasis?

A

Small red scaly tear drop shaped spots that show up all over the skin for some psoriasis patients

97
Q

What 3 main doctors are involved with managing psoriasis and what may they do?

A

Psychologist- help with mental health, workplace disability, personality traits, sleeping disorders

Dermatologist- skin symptoms

Rheumatologist- joint symptoms

98
Q

What are some topical therapies for managing psoriasis?

A

Vitamin D analogues
Topical corticosteroids
Retinoids

99
Q

What types of phototherapy are used to manage psoriasis?

A

Narrowband UVB

PUVA

100
Q

What medication is given to patients with psoriasis to help manage hand dermatitis?

A

Retinoids

101
Q

What systemic immunosupressants may be prescribed to patients with psoriasis?

A

Methotrexate
Ciclosporin
Fumaric acid esters
Apremilast

102
Q

What is atopic eczema?

A

An intensely pruritic chronic inflammatory condition

103
Q

What does pruritic mean?

A

Gives a strong urge to itch/scratch at

104
Q

How does atopic eczema mainly manifest in infants?

A

Inflammation of cheeks, scalp and extensors

105
Q

How does atopic eczema mainly manifest in children and adults?

A

Flexural inflammation and lichenification

106
Q

How is atopic eczema treated?

A

Daily emollients and anti inflammatory therapy

107
Q

In the pathophysiology of eczema what are the main barrier defects?

A

Filaggrin causes keratin bundles and intermediate filaments to form cellular scaffolds
Increased TEWL (transepidermal water loss)
Reduced extracellular lipids and impaired ceramide production
Impaired protection against microbes and environmental allergens

108
Q

What is filaggrin and what does it do?

A

Filament aggregating protein- it forms keratin bundles and cellular scaffolds of filament

109
Q

What is TEWL and how is it affected in atopic eczema?

A

Transepidermal water loss

110
Q

In the pathophysiology of eczema what occours to cuase immune dysregulation?

A

There is a bias towards Th2 responses
Staphylococcal antigens stimulate Th2
Microbiome makes the eczema worse

111
Q

What is fissuring in the context of eczema?

A

Cleavage of the skin often extending into the dermis

112
Q

What is impetiginisation in the context of atopic eczema? What does it look like?

A

When skin lesions become infected by streptococci or staphylococci, looks like a gold crust on the skin with peeling

113
Q

What is venous stasis eczema?

A

When due to circulation problems in the veins, blood leaks out into skin

114
Q

What causes eczema herpeticum?

A

Herpes simplex virus

115
Q

What is eczema herpeticum?

A

Outburst from viral infection resulting in red spots erupting on the body, must be treated as an emergency

116
Q

How can lifestyle be changed to manage atopic eczema?

A

Use of daily emollients, omission of soap

117
Q

What are some topical therapies for managing eczema?

A

Topical corticosteroids

Retinoids (for hand dermatitis)

118
Q

What phototherapies are used for managing eczema?

A

Narrowband UVB

PUVA (for hand dermatitis)

119
Q

What systemic immunosupressants may be prescribed for eczema?

A

Methotrexate
Ciclosporin
Azathioprine
Mycophenolate mofetil

120
Q

What are some advanced treatments for psoriasis and atopic eczema and what do they involve?

A

They involve biologics

Psoriasis: JAK inhibitors, anti- TNF/IL17/IL23
Atopic eczema: JAK inhibitiors, anti-IL-4alpha/ IL13

BRS Y1 (52 decks)

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