Physiology Flashcards
(522 cards)
1
Q
Examples of skin conditions with increasing prevalence (3)
A
Skin cancers
Venous Leg Ulceration
Atopic Dermatitis
2
Q
Examples of skin conditions with decreasing prevalence (3)
A
Leprosy
Viral Exanthem
HIV-related skin disease
3
Q
Epidermis
A
Outer layer of the skin
4
Q
Epidermis: Main cell type
A
Keratinocytes (95% of the layer)
5
Q
Dermis
A
Skin layer beneath the epidermis
6
Q
Dermis components
A
Connective tissue
7
Q
Embryology: Epidermis origin
A
Ectoderm cells from a single layer periderm
8
Q
Embryology: Dermis origin
A
Formed from the mesoderm below the endoderm
9
Q
Embryology: Melanocyte Origin
A
Neural crest
10
Q
Foetal Skin Development: What has developed at 4 weeks?
A
Periderm
Basal Layer
Dermis
11
Q
Foetal Skin Development: Foetal term for Dermis
A
Corium
12
Q
Foetal Skin Development: What has developed at 16 weeks?
A
Keratin layer
Granular layer
Prickle Cell layer
Basal layer
Dermis
13
Q
Blaschko’s Lines
A
Developmental growth patterns of the skin that do not follow blood vessels, nerves or lymphatics
14
Q
Examples of Skin Appendages (4)
A
Nails
Glands
Hair
Mucosae
15
Q
Skin Structure: What is the sub-cutis predominantly made of?
A
Adipose tissue
16
Q
Epidermis: Cell layer
A
Stratified squamous epithelium
17
Q
Epidermis: Thickness
A
1.5mm
18
Q
Epidermis: What proteins are present?
A
Structural keratins
19
Q
Epidermis: How is movement provided?
A
By the basement membrane
20
Q
Epidermis: Number of layers
A
4
21
Q
Epidermis: Layers (4)
A
Keratin Layer
Granular Layer
Prickle Cell Layer
Basal Layer
22
Q
Epidermis: Cell Types Involved (4)
A
Keratinocytes
Melanocytes
Langerhans Cells
Merkel Cells
23
Q
Epidermis: Function of Merkel Cells
A
Sensory function
24
Q
Epidermis: Cell variation and differentiation is controlled by what? (3)
A
Growth Factors
Cell death
Hormones
25
Epidermis: Differentiation process
Keratinocytes migrate from the basement membrane
26
Epidermis: How long does it take for keratinocytes to migrate from the basement membrane to the surface?
28 days
27
Epidermis: Difference in the sole of the foot
Thick keratin layer due to area of high pressure
28
Basal Layer: Cell type
One cell thick small cuboidal cells
29
Basal Layer: Contains what protein?
Intermediate keratin filaments
30
Basal Layer: Metabolic action
High
31
Prickle Cell Layer: Cell type
Large Polyhedral Cell
32
Prickle Cell Layer: What cellular structure is present?
Desmosomes
33
Prickle Cell Layer: What proteins are present?
Intermediate filaments - to connect desmosomes
34
Granular Layer: High ... content
Lipid
35
Granular Layer: Cellular structure
2-3 layers of flat cells
36
Granular Layer: What are the two signature organelles?
Keratohyalin Granules
Odland Bodies
37
Granular Layer: Large Keratohyalin Granule function
Contain structural filaggrin and involucrin proteins
38
Granular Layer: Odland Body function
Lamellar bodies that contain lipids
39
Granular Layer: This is the origin of what?
Cornified envelope
40
Granular Layer: Key feature of the cells of this layer
No cell nuclei
41
Keratin Layer: 80% of this layer is formed of what?
Keratin and Filaggrin
42
Keratin Layer: Generates what type of barrier?
Waterproof
43
Keratin Layer: Cell type of this layer
Corneocytes
44
Keratin Layer: Corneocytes
Overlapping non-nucleated cell remnants
45
Keratin Layer: Forms what type of envelope?
Insoluble and Cornified
46
Keratin Layer: Lamellar granules have what function?
Release lipids
47
Keratin Layer: Associated Disease example
HPV infects keratinocytes to form warts
48
Mucosal Membranes: Highly specialised function where? (5)
Eyes
Mouth
Nose
Gastrointestinal tract
Genitourinary tract
49
Mucosal Membranes: Oral Mucosa example of specialised area of mucosa
Tongue papillae for taste
50
Mucosal Membranes: How does this benefit mastication in the oral cavity?
Keratinised mucosa can deal with friction and pressure
51
Mucosal Membranes: The lining mucosa of the oral cavity has what property?
Non-keratinised
52
Epidermal Cells: 4 Main cell types
Keratinocytes
Melanocytes
Langerhans Cells
Merkel Cells
53
Epidermal Cells: location of Keratinocytes
Epidermis
54
Location of Melanocytes
Basal and Suprabasal
55
Location of Langerhans cells
Suprabasal
56
Location of Merkel Cells
Basal
57
Melanocytes: Migration pattern
Migrate from the neural crest to the epidermis in the first 3 months of foetal development
58
Melanocytes: Location
Basal layer and above
59
Melanocytes
Pigment-producing dendritic cells
60
Melanocytes: Cellular feature of cytoplasm
Larger than surrounding keratinocytes
61
Melanocytes: These cells contain what main organelle?
Melanosomes
62
Melanocytes: Function of melanosomes
Produce skin pigmentation as they allow the migration of melanin to keratinocytes
63
Melanocytes: Convert ... to ...
Tyrosine to Melanin
64
Melanocytes: Eumelanin colour
Brown or black
65
Melanocytes: What type of melanin is brown or black?
Eumelanin
66
Melanocytes: Phaeomelanin colour
Red or Yellow
66
Melanocytes: What melanin type is red or yellow?
Phaeomelanin
67
Melanocytes: Function of melani
Acts as a neutral density filter of light as a protective function over the nucleus to protect DNA
68
Melanocytes: What wavelengths does melanin absorb?
All wavelengths
69
Conditions affecting Skin Colour: Vitiligo
Autoimmune disease associated with loss of melanocytes
70
Conditions affecting Skin Colour: Albinism
Genetic partial loss of pigment production
71
Conditions affecting Skin Colour: Addison's Disease
Excess ACTH from the pituitary gland causes excess melanocyte stimulating hormone to cause excess pigmentation
72
Conditions affecting Skin Colour: Nelson's Syndrome
Melanin Stimulating Hormone is produced in excess by the pituitary
73
Conditions affecting Skin Colour: Malignant Melanoma
Tumour of the melanocyte cell line
74
Langerhans Cells: Origin
Mesenchymal
75
Langerhans Cells: Location of origin
Bone marrow
76
Langerhans Cells: What level are they located in the epidermis?
Prickle cell layer
77
Langerhans Cells: Locations (3)
Dermis
Lymph Nodes
Prickle cell level in the Epidermis
78
Langerhans Cells: These are found alongside what structure?
Birbeck granules
79
Langerhans Cells: Function
Skin Immune System
80
Merkel Cells: Location
Basal cell layer
81
Merkel Cells: Located between what two structures?
Keratinocytes
Nerve fibres
82
Merkel Cells: Function
Mechanoreceptors to detect pressure
83
Merkel Cells: Merkel Cell Cancer is caused by what?
Viral infection
84
Hair Follicles: Scientific term for hair follicle
Pilosebaceous Unit
85
Hair Follicles: Adjacent to what structures?
Sebaceous glands
86
Hair Follicles: Hair pigmentation is determined by what?
Melanocytes above the dermal papilla
87
Hair Follicles: Contains specialised what?
Keratins
88
Hair Follicles: Develops from what structure?
Hair Bud
89
Hair Follicles: Anagen phase
Growth phase
90
Hair Follicles: Anagen phase time period
3-7 years
91
Hair Follicles: What is present in the Anagen phase?
Dermal papilla
92
Hair Follicles: Catagen phase
Involution or Dying Phase
93
Hair Follicles: Catagen time period
3-4 weeks
94
Hair Follicles: Process during Catagen phase
Hair bulb retracts upwards to the surface
95
Hair Follicles: Telogen Phase
Resting or Shedding Phase
96
Hair Follicles: Telogen Phase hair shape during this phase
Club shaped
97
Hair Follicles: Impact during pregnancy
Excess growth during pregnancy
Then excess shedding afterwards
98
Hair Follicles: How are these changed by the menopause?
Due to changes in oestrogen levels
99
Alopecia Areata
Autoimmune disease of hair loss
100
Hair Follicles: What hormones may influence growth? (2)
Thryoxine
Androgens
101
Hair Follicles: Lanugo
In utero hair state
102
Nails: Contain specialised what?
Keratins
103
Nails: What is the origin of growth?
Nail matrix or root
104
Nails: Growth rate is greater where?
Fingers
105
Nails: Growth rate is greatest when?
Summer
106
Nails: 3 parts of the nail
Dorsal
Intermediate
Ventral
107
Nails: Dorsal part
Upper layer of the nail
108
Nails: Ventral part of the nail
Lower part of the nail
109
Nails: Dystrophic nails can be due to what?
HPV
110
Nails: Sub-ungal subkeratosis can be due to what?
Fungal infection
Skin disorders with fast cell turnover e.g. Psoriasis
111
Nails: Tuberous Sclerosis
Benign tumours of the nail
112
Derma-epidermal Junction: Functions as an interface between what?
Epidermis and Dermis
113
Derma-epidermal Junction: Functions to stick what together?
Basal Keratinocytes and the papillary dermis
114
Derma-epidermal Junction: Acts as a ... membrane
Semi-permeable
115
Derma-epidermal Junction: What disorder is due to disruption to this?
Bullous Pemphigoid
116
Derma-epidermal Junction: Bullous Pemphigoid Pathophysiology
Antibodies attack the dermo-epidermal junction to form bullae and itchiness
117
Dermis: Cells involved (5)
Fibroblasts
Macrophages
Mast Cells
Lymphocytes
Langerhans Cells
118
Dermis: Function of Fibroblasts
Generate collagen and elastin
119
Dermis: Fibres present (2)
Collagen
Elastin
120
Dermis: Differences in Asian/Hispanic/Latino/African dermis
Thicker
121
Dermis: Ethnicities with a thicker dermis
Asian
Hispanic
Latino
African
122
Dermis: Differences in African skin
Larger and more numerous fibroblasts and macrophages
123
Dermis: Darker skin types have what difference?
Smaller collagen fibres that are more closely stacked and run in parallel to the epidermis
124
Dermis: Intrinsic Skin Ageing description
Reduced collagen
125
Dermis: Extrinsic Skin Ageing is due to what?
Pollutants
UV
Smoking particles
126
Blood Vessels: Location of large vessels
Subcutaneous Fat Level
127
Blood Vessels: Location of deep vascular plexus
Level of the hair bulb
128
Blood Vessels: Angioma
Benign dilation of the blood vessels in the dermal tissue to cause bumpy red eruptions with easy bleeding
129
Lymphatic Vessels: Progress from ... to ....
Small non-contractile vessels
Large contractile lymphatic trunks
130
Lymphatic Vessels: Function - Enables the continual drainage of what?
Plasma proteins
Extravasated cells
Excess interstitial fluid
131
Lymphatic Vessels: Functions - Channelling of (2)
Microorganisms
Toxins
132
Lymphatic Vessels: Chronic Lymphoedema
Recurrent episodes of cellulitis causes inflammation and dilation to cause swelling
133
Nerves: Function of Pacinian Special Receptors
Detect pressure
134
Nerves: Function of Meissners Corpuscles
Detect Vibration
135
Neurofibromatosis
Tumour overgrowth developments on nerve tissue
136
Pilosebaceous Unit: Composed of what 4 structures?
Hair follicle
Hair shaft
Erector pili muscle
Sebaceous glands
137
Pilosebaceous Unit: Upper segment name
Infundibulum
138
Pilosebaceous Unit: Middle segment name
Isthmus
139
Pilosebaceous Unit: Isthmus function
Region where the sebaceous glands open into the hair follicle and stem cells are present
140
Pilosebaceous Unit: Lower base segment name
Hair bulb
141
Pilosebaceous Unit: Asian hair structure features
Straight and round
Large cross-sectional area
Fastest growth rate
Strong and durable
142
Pilosebaceous Unit: African hair structure features
Curl or spiral
Ellipsoidal cross section
Lower hair density
Slowest growth rate
Most fragile
143
Pilosebaceous Unit: Caucasian hair structure features
Straight to curly hair
Round or oval cross section
Highest hair density
Most moisture content
Strong and durable
144
Alopecia Areata
Autoimmune disorder in which antibodies attack the hair follicles dermal root to cause fallout
145
Hirsutism
Hair present in excess in inappropriate locations due to genetics or imbalance in androgens
146
Skin Glands: Apocrine Glands Function
Discharges contents into the hair follicle
147
Sebaceous Glands: Location
Face and Chest
148
Sebaceous Glands: Sensitive to what?
Hormones
149
Sebaceous Glands: When are they quiescent?
Pre-puberty
150
Sebaceous Glands: Produce what?
Sebum
151
Sebaceous Glands: Contents of sebum (4)
Squalene
Wax esters
Triglycerides
Free Fatty Acids
152
Sebaceous Glands: Secretion opening enters what canal?
Piliary
153
Sebaceous Glands: Functions (3)
Control moisture loss
Protect from fungal infection
Produces sticky oil to lubricate the hair follicle
154
Sebaceous Glands: What disease is distributed towards this structure?
Acne
155
Apocrine Glands: Develop as part of what?
Pilosebaceous unit
156
Apocrine Glands: Located where?
Axilla
Groin
Eyelids
Ears
Mammary region
Perineal region
157
Apocrine Glands: Dependent on what hormones?
Androgens
158
Apocrine Glands: Produces what?
Oily fluid
159
Apocrine Glands: Why does the oil smell at times?
Due to bacterial decompensation
160
Eccrine Glands: Located where?
Palms
Soles
Forehead
Axilla
161
Eccrine Glands: What is the nerve supply?
Sympathetic Cholinergic nerves
162
Eccrine Glands: Stimulated by what 3 factors?
Mental
Thermal
Gustatory
163
Eccrine Glands: Functions (2)
Discharges sweat with high water content for filtration and thermoregulation
Cool the body by evapouration
Moisten the palms and soles to aid grip
164
Skin Immunology: What structures contribute to the immunological function of the skin? (2)
Stratum corneum - Keratin Layer
Stratification
165
Skin Immunology: Cells contributing to the immune function of the skin (2)
Immune system cells
Keratinocytes
166
Keratin Layer: Rich in what?
Lipid
167
Keratin Layer: Features (2)
Tough
Physical barrier
168
Keratin Layer: Formed by what?
Terminal differentiation of keratinocytes to corneocytes
169
Epidermal Layer: Keratinocytes - Produce what?
Anti-microbial peptides
170
Epidermal Layer: Keratinocytes - Antimicrobial peptide function
Directly kill pathogens
171
Epidermal Layer: Keratinocytes - Role of these cells in Psoriasis
High antimicrobial peptide levels in the skin of psoriatic patients
172
Epidermal Layer: Keratinocytes - Produce what immune molecules?
Cytokines
Chemokines
173
Epidermal Layer: Langerhans Cells - Classified as what type of cell?
Antigen presenting cell
174
Epidermal Layer: Langerhans Cells - Located where in the epidermis?
Interspersed between keratinocytes
175
Epidermal Layer: Langerhans Cells - Characterised by what?
Birbeck Granule
176
Epidermal Layer: Langerhans Cells - Birbeck Granule functions (2)
Act as sentinels in the epidermis
Process antigen and microbial fragments to present them to effector T cells
177
Epidermal Layer: Langerhans Cells - Derived from what cell line?
Macrophage lineage
178
Epidermal Layer: Langerhans Cells - What disease are they involved in?
Langerhans Histiocytosis
179
Epidermal Layer: T Cells - What type is mainly found in epidermis?
CD8+ T cells
180
Epidermal Layer: T Cells - What type is found in the epidermis?
CD4+ and CD8+ T cells
181
Epidermal Layer: T Cells - What type of T cell is involved in Psoriasis?
TH1
182
Epidermal Layer: T Cells - What type of T cell is involved in Atopic Dermatitis?
TH2
183
Epidermal Layer: T Cells - What type of T cell is involved in Atopic Dermatitis and Psoriasis?
TH17
184
Epidermal Layer: TH1 T Cells - function
Activate macrophages to destroy microorganisms
185
Epidermal Layer: TH1 T Cells - secrete what? (2)
IL-2
IFN-gamma
186
Epidermal Layer: TH1 T Cells - Associated with what disease?
Psoriasis
187
Epidermal Layer: TH2 T Cells - Function
Help B cells to make antibody
188
Epidermal Layer: TH2 T Cells - Secrete what? (3)
IL-4
IL-5
IL-13
189
Epidermal Layer: TH2 T Cells - Associated with what disease?
Atopic Dermatitis
190
Epidermal Layer: TH17 T Cells - Function
Modulates skin and mucosal immunity
191
Epidermal Layer: TH17 T Cells - Secretes what?
IL-17
192
Dermal Layer: Dendritic Cells - Function
Uptakes antigens and presents them
193
Dermal Layer: Dendritic Cells - Function of Plasmacytoid Dendritic Cells
Main source of alpha-IFN to transmit information to T and B cells
194
Dermal Layer: Dendritic Cells - Constantly rotate between what?
Skin and Lymph nodes
195
Dermal Layer: Mast Cells - Preformed mediators (4)
Tryptase
Chymas
TNF
Histamine
196
Dermal Layer: Mast Cells - Newly Synthesised Mediators (3)
Interleukins
TNF
TGF-Beta
197
Skin Function: Physical Function
Barrier to friction, mechanical trauma and UV
198
Skin Function: Chemical function
Barrier to irritants, allergens and toxins
199
Steroid Sulphatase Deficiency X-Linked Ichthyosis
Incapacity to produce cholesterol properly in the skin so forms dry skin
200
Cumulative Irritant Hand Dermatitis
Flaking and scalin involving the epidermis and dermis of the skin in between fingers and on the finger tips
201
Skin Function: Metabolic Function - Process of Vitamin D metabolism
UV-B converts 7-dehydrocholesterol to Vitamin D23
202
Other name for Vitamin D23
Cholecalciferol
203
Skin Function: Metabolic Function - Vitamin B is stored in the liver as what?
Hydroxycholecalciferol
204
Skin Function: Metabolic Function - Hydroxycholecalciferol is converted to what and where in Vitamin D metabolism?
1,25-Dihydoxycholecalciferol in the kidney
205
Skin Function: Metabolic Function - Thyroid Hormone function
Converts Thyroxine (T4) To Triiodothyronine (T3)
206
T4
Thyroxine
207
T3
Triiodothyronine
208
Vitamin D: Soluble in what?
Fat
209
Vitamin D
Pro-hormone essential for calcium and phosphorous metabolism
210
Vitamin D: Function for the bone
Enables normal mineralization of the bone
211
Vitamin D: Function with regards to Calcium
Increases flow of calcium into the blood stream by promoting the absorption of calcium and phosphorous from food in the intestines and reabsorption of calcium in the kidneys
212
Vitamin D: D2 name
Calciferol
213
Vitamin D: D3 name
Cholecalciferol
214
Vitamin D: Vitamin D2 is made from what?
Inactive pro-vitamin ergosterol in plants by the action of sunshine
215
Vitamin D: Vitamin D3 is provided by what foods?
Oily fish
Eggs
Meat
216
Vitamin D: How is Vitamin D3 made in the skin?
UVB action on 7-dehydrocholesterol
217
Vitamin D: 1,25-Dihydroxycholecalciferol alternate name
Calcitriol
218
Vitamin D: Calcitriol
Biologically active hormonal form of Vitamin D that is used in the body to form and maintain the bones
219
Vitamin D: How is calcitriol formed?
From cholecalciferol in the liver and kidney
220
Failed Skin Functions: What happens if there is fluid loss?
Dehydration
221
Failed Skin Functions: What happens if there is protein loss?
Hypoalbuminaemia
222
Failed Skin Functions: What happens if there is failed barrier? (3)
Infection
Fluid loss
Protein loss
223
Failed Skin Functions: What happens if there is failed thermoregulation
Hypothermia
224
Failed Skin Functions: What happens if there is failed immune defences?
Spread of infection
225
Failed Skin Functions: What happens if there is failure in metabolism?
Disordered thyroxine metabolism
226
Failed Skin Functions: What happens if there is failed sensation? (3)
Pain senation
Numbness
Failure to detect changes in pressure or temperature
227
Why did people evolve dark skin?
Protect against skin cancer
228
Wound
Any break in the skin
229
Wounds: Small surgical wounds heal by what?
Primary intention
230
Wounds: What can compromise the healing of surgical wounds? (4)
Haematoma
Infection
Poor suture technique
Dehiscence
231
Wounds: When is secondary intention healing used?
For large wounds that are too tight to stick or areas where distortion is possible
232
Burns: First degree burn only affects what?
Epidermis
233
Burns: Second degree and partial thickness burns affect what?
Epidermis and the Dermis
234
Burns: Third Degree and full thickness burns affect what?
Beyond the dermis
235
Burns: Superficial burn description
Erythematous
Wet
Extremely painful
236
Burns: Deep Burn description
White, Black or Charred
Dry
Numb
237
Secondary Intention Healing: Stage I name
Inflammatory Stage
238
Secondary Intention Healing: Stage II name
Proliferation and Tissue Remodelling
239
Secondary Intention Healing: Stage III name
Tissue remodelling
240
Secondary Intention Healing: Stage I platelet role
Form an initial clot and release inflammatory mediators
241
Secondary Intention Healing: Stage I Leucocyte role
Act in the wound bed by phagocytosing bacteria and scavenging cellular debris
242
Secondary Intention Healing: Stage I what becomes prominent at the end of this stage?
Keratinocyte proliferation and new tissue formation
243
Secondary Intention Healing: Stage II - Action of cells
Regenerate the epithelium of the wound surface
244
Secondary Intention Healing: Stage II - What type of tissue formation is stimulated?
Granulation
245
Secondary Intention Healing: Stage II - What is the role of fibroblasts?
Lay down matrix
Contracts the wound
246
Secondary Intention Healing: Stage II - Endothelial cells generate what?
New blood vessels
247
Secondary Intention Healing: Stage III - New tissue is converted into what?
Mature scar tissue
248
Secondary Intention Healing: Stage III - Role of fibroblasts in this phase?
Lay down collagen to improve tensile strength of. the scar
Restore normal dermal matrix
249
Chronic Wounds: Presents for how long?
>6 weeks
250
Chronic Wounds: Most common
Leg ulcers
251
Chronic Wounds: Heal from what?
Edges of the wound
252
Chronic Wounds: Colour
Yellow or Green
253
Chronic Wounds: Adheres to what?
Underlying tissues
254
Chronic Wounds: What is on the surface?
Slough
255
Slough
Mixture of dead cells, polymorphs and bacteria
256
Chronic Wounds: Disadvantages of slough
Possesses inhibitory effects on the healing ability of a wound
257
Chronic Wounds: Disadvantages of slough
Possesses inhibitory effects on the healing ability of a wound
258
Pressure Sores: Aetiology (4)
Prolonged pressure over a bony area
Lack of blood flow
Friction from bedding or clothing
Irritation from sweat, blood, urine or faeces
259
Pressure Sores: Stage I symptoms
Tender
Itchy
Painful
260
Pressure Sores: Stage I description
Unbroken skin that presents red or pink with a mild sunburn appearance
261
Pressure Sores: Stage II description
Red, swollen and painful skin with broken or intact blisters
262
Pressure Sores: Stage III description
Sore has broken through the skin and wound extends into the deeper layers of the skin
263
Pressure Sores: Stage III what may be present?
Crater-like ulcers
264
Pressure Sores: Stage IV description
Sore extends pas the skin into fat, muscle and bone tissue
265
Eschar
Blackened dead tissue
266
Pressure Sores: Management (40
Turn regularly
Keep skin clean and hydrated
Ensure regular skin assessment
Goof nutrition
267
Give an example of a region of the skin that is impenetrable
Stratum cornea
268
Staphylococcus aureus: Infection can present as what? (7)
Superficial lesions - Boils and Abscesses
Toxinoses
Carbuncle
Impetigo
Folliculitis
Rash
Scalded Skin Syndrome
269
Staphylococcus aureus: Infects what areas of the skin? (2)
Anterior nares
Perineum
270
Staphylococcus aureus: MRSA is defined by what?
Flucloxacillin resistance
271
Staphylococcus aureus: Those at risk to infection (5)
Elderly
Immunocompromised
Burns patients
Surgical patients
Patients with IV lines or Dialysis
272
Staphylococcus epidermidis: Risk factors (2)
Foreign devices e.g. catheters
Immunocompromised patients
273
Virulence Factors: Adhesin
Enables the binding of an organism to host tissue
274
Virulence Factors: Invasin
Enables an organism to invade a host cell or tissue
275
Virulence Factors: Impedin
Enables the organism to avoid host defence mechanisms
276
Virulence Factors: Aggressin
Causes direct damage to the host
277
Virulence Factors: Modulin
Induces damage to the host directly
278
Virulence Factors: Staphylococcus aureus example of an adhesin
Fibrinogen Binding Protein
279
Virulence Factors: Staphylococcus aureus 3 examples
Coagulase
Leukocidin
TSST-1 Toxin
280
Toxinoses
Discrete diseases associated with a single protein component of a toxin or exotoxin
281
Toxinoses: 3 examples
TSST-1
Staphylococcal Food Poisoning
SSS
282
Toxinoses: Symptoms of TSST-1
Rapid 48 hour fever
Diarrhoea
Vomiting
Sore throat
Muscle pain
283
Toxinoses: Staphylococcal food poisoning is caused by what toxin?
Enterotoxin Se-A, -B and -C
284
Toxinoses: How does Staphylococcal Food Poisoning present?
Intoxication with Diarrhoea and Vomiting within 1-5 hours
285
Toxinoses: SSS
Scalded Skin Syndrome
286
Toxinoses: What causes SSS?
ETA and ETB Exfoliatin toxins
287
Toxinoses: ETA and ETB toxins target what?
Desmoglein-1
288
Toxinoses: SSS often affects who?
Neonates
289
Toxinoses: SSS affects what areas?
Face
Axilla
Groin
290
Example of a superantigen
TSST-1
291
TSST-1
Toxic Shock Syndrome Toxin 1
292
TSST-1: Common cause of what?
Toxic Shock Syndrome
293
TSST-1: Activates what
T cells
294
TSST-1: Mode of action
Superantigen is not processed by polymorphonuclear neutrophils but binds to the MHC-II to activate immune cells and induce a release of cytokines
295
Toxic Shock Syndrome: Diagnostic Criteria (4)
Fever (>39 degrees) - with myalgia, headache and nausea
Diffuse macular rash with desquamation and erythema
Hypotension - <90 mmHg
>3 organ systems involved - Liver, Blood, Renal, Mucous membranes, GIT, Muscular system and. the CNS
296
Adhesins
Extracellular matrix molecules present on the epithelial and endothelial surfaces to colonise sites of the body and a component of blood clots
297
Adhesins: Type associated with streptococcus
CIfA or CIfB
298
Adhesins: Type associated with osteomyelitis
CNA
299
Panton-Valentine Leukocidin
Specific secreted proteins that form one functional complex to attack white blood cells
300
Panton-Valentine Leukocidin: What toxins are involved?
lukS and lukF
301
Panton-Valentine Leukocidin: Toxin has a specific toxicity for what?
Leukocytes
302
Panton-Valentine Leukocidin: What skin infections are associated with PVL?
Recurrent furunculosis
Necrotising fasciitis
303
Panton-Valentine Leukocidin: PVL with alpha toxin are linked to what?
CA-MRSA
304
Panton-Valentine Leukocidin: What does CA-MRSA cause?
Necrotising pneumonia
Contagious skin infections
305
Necrotising Pneumonia: Features (4)
Preceding influenza-like syndrome
Necrotizing haemorrhagic penumonia
Acute respiratory distress
Multi-organ failure
306
Streptococcus pyogenes: Gram Stain
Gram positive cocci in chains
307
Streptococcus pyogenes: Type of haemolysis
Beta Haemolysis
308
Streptococcus pyogenes: What 3 skin infections can it cause?
Impetigo
Cellulitis
Necrotising fasciitis
309
Streptococcus pyogenes: What haemolysins do they produce?
SLO
SLS
310
Streptococcus pyogenes: What protein does it produce?
M protein
311
Lancefield Classification
Surface carbohydrate classification utilised in Group A identification
312
Lancefield Classification: Enables serotyping of what?
Cell wall carbohydrates
313
Lancefield Classification: Major Serotypes (2)
A-H
K-V
314
Group A Microorganisms: M protein subdivisions (2)
Major - M1 and M3
Severe Invasive Disease - M3 and M18
315
Group A Microorganisms: M proteins for major division
M1 and M3
316
Group A Microorganisms: M proteins for severe invasive disease
M3 and M18
317
Group A Microorganisms: M proteins are encoded by what?
Emm gene
318
Group A Microorganisms: M protein binds to what? (3)
Factor M
Fibronectin
Fibrinogen Albumin
319
Examples of Streptococci Skin Diseases (3)
Impetigo
Cellulitis
Necrotising fasciitis
320
Group A Streptococci Diseases: Impetigo - Infection is located where?
Superficial
321
Group A Streptococci Diseases: Impetigo - Is this a localised or systemic?
Localised
322
Group A Streptococci Diseases: Impetigo - Entry point
Small defect in the skin
323
Group A Streptococci Diseases: Impetigo - Limited to what structure?
Stratum corneum
324
Group A Streptococci Diseases: Impetigo - Often associated with what population group?
Children
325
Group A Streptococci Diseases: Impetigo - Mechanism of spread
Contact with discharge on the face and scratching
326
Group A Streptococci Diseases: Cellulitis - Infection of what structure?
Dermis and associated subcutaneous fat
327
Group A Streptococci Diseases: Cellulitis - Erysipelas localised to where?
Upper dermis and lymphatic system
328
Group A Streptococci Diseases: Cellulitis - Symptoms
Fevers
Rigors
Nausea
329
Group A Streptococci Diseases: Necrotising Fasciitis - Pathophysiology
Invasive streptococci A strains penetrate the mucous membrane to develop a lesion
330
Group A Streptococci Diseases: Necrotising Fasciitis - Rapidly destroys what?
Connective tissue
331
Group A Streptococci Diseases: Necrotising Fasciitis - What is the cause of type I?
Clostridia species
332
Group A Streptococci Diseases: Necrotising Fasciitis - What is the cause of type II?
S. pyogenes or aureus
333
Haemolysins: Example
Streptolysin S
334
Haemolysins: SLS forms what?
Pores
335
Haemolysins: SLS is toxic to what? (3)
PMN
Organelles
Platelets
336
Haemolysins: SLS is responsible for what?
Beta Haemolysis
337
Hypersensitivity
Exaggerated immune response that causes collateral damage to the self due to exaggeration of the normal immune mechanisms
338
Allergy
Hypersensitivity disorder of the immune system where the immune system reacts to a normally harmless substance in the environment
339
Allergen
A substance that causes a reaction
340
Type I Allergy: Mediated by what?
IgE
341
Type I Allergy: Routes of exposure
Skin contact
Inhalation
Ingestion
Injection
342
Type I Allergy: Reaction occurs when?
Within minutes to. 2hours after exposure to an allergen
343
Type I Allergy: What interleukins are involved?
IL-4
IL-5
IL-13
344
Type I Allergy: 3 potential reactions to the skin
Urticaria
Angioedema
Anaphylaxis
345
Type I Allergy: Urticaria description
Itchy lesions that appear within 1 hour and last 2-24 hours
346
Type I Allergy: Urticaria is caused by what?
Dilation of blood vessels and leakage of fluid into the tissue
347
Type I Allergy: Angioedema description
Localised non-pitting swelling of the subcutaneous tissue or mucous membranes that isn't itchy
348
Type I Allergy: Anaphylaxis is characterised by what?
Rapidly developing life threatening problems
- Airway oedema - bronchospasm and tachypnoea
- Circulation complications. -Hypotension and Tachycardia
349
Type I Allergy: Gastrointestinal symptoms
Nausea
Diarrhoea
Vomiting
Colicky abdominal pain
350
Type I Allergy: Respiratory clinical presentation
Nasal itching
Sneezing
Rhinorrhoea
Wheezing
Asthma
351
Type I Allergy: Trend in Tryptase
Peaks at 1-2 hours and returns to normal by 6 hours during anaphylaxis
352
Type I Allergy: Adrenaline dose for adults
300 micrograms
353
Type I Allergy: Adrenaline dose for children
150 micrograms
354
Type I Allergy: Adrenaline Autoinjector is used when?
Previous anaphylaxis
Difficult allergy
Background of asthma
Live in a rural area
355
Type IV Allergy: Mediated by what?
T Cells
356
Type IV Allergy: Causes what common skin condition?
Allergic contact dermatitis
357
Type IV Allergy: Onset of reaction
12-24 hours
358
Type IV Allergy: Routes of exposure
Direct skin contact
Airborne contact
Injection
359
Type IV Allergy: First phase of these reactions
Sensitisation Phase
360
Type IV Allergy: Second phase of these reactions
Re-exposure Phase
361
Type IV Allergy: Sensitisation - Hapten is taken up by what in the skin?
Langerhan Cells
362
Type IV Allergy: 4 examples of this type of reaction in the skin
Allergic Contact Dermatitis
Photo-allergy
Skin response to microorganism
Abnormal delayed response in atopic dermatitis
363
Type IV Allergy: Allergic Contact Dermatitis clinical presentation
Small blisters and erosions
364
Type IV Allergy: Investigations
Patch Testing
365
Type IV Allergy: Protocol of Patch Testing
Finn chambers containing the allergen are applied on the back and removed and read within 48-96 hours
366
Irritant Contact Dermatitis: This is a ... process
Non-immunological
367
Irritant Contact Dermatitis: Due to what?
Contact with agents that abrade, irritate and traumatise the skin
368
Irritant Contact Dermatitis: Does not require what?
Prior sensitisation
369
Irritant Contact Dermatitis: Pattern depends on what?
Exposure
370
Endogenous Dermatitis: Atopic Eczema - Clinical Presentation
Dry skin of the flexors
371
Endogenous Dermatitis: Atopic Eczema - Often associated with what?
Asthma and Hayfever
372
Endogenous Dermatitis: Two types
Atopic eczema
Psoriasis
373
Endogenous Dermatitis: Psoriasis - Clinical presentation
Scaly plaques on extensor surfaces
374
Management of Acute Allergic Reactions: Stage I
Chlorophenaomine on first sign
375
Management of Acute Allergic Reactions: Stage II
Prednisolone if symptoms worsen over the 30 minutes
376
Management of Acute Allergic Reactions: Stage III
Intramuscular Adrenaline if the patient becomes blue or collapses
377
Management of Acute Allergic Reactions: Dose of Adrenaline
10mg/kg
>30kg - 300mg
15-30kg - 150mg
378
How does dry skin protect the skin?
Desiccates microorganisms
379
How does sebum protect the skin?
Inhibits bacterial growth by fatty acids
380
Diagnosis of Bacterial Skin Infections
Sample taken and transported in medium
381
What samples should be taken for bacterial skin infections?
Swab or lesion if the skin is broken
Pus or tissue if there is a deeper lesion
Blood cultures - must take aerobic, anaerobic and paediatric
382
Skin Infections: Staphylococcus - Gram staining
Gram positive cocci in clusters
383
Skin Infections: Staphylococcus - Coagulase positive
Staphyloccus aureus
384
Skin Infections: Staphylococcus - Coagulase negative
Staphylococcus epidermidis
Staphylococcus saprophyticus
385
Skin Infections: Staphylococcus - What is the only staphylococcus to test positive for latex agglutination?
Staphylococcus aureus
386
Skin Infections: Staphylococcus - How does coagluase positive present?
Golden
387
Skin Infections: Staphylococcus - How does coagulase negative present?
White
388
Skin Infections: What is the most common human pathogen
Staphylococcus aureus
389
Skin Infections: Staphylococcus aureus - Antibiotic of choice if MRSA negative
Flucocloxacillin
390
Skin Infections: Staphylococcus aureus - What toxins does it produce?
Staphylococcal scalded skin syndrome toxin
Panton Valentine Leucocidin
Enterotoxin
391
Skin Infections: Staphylococcus aureus - Treatment options for MRSA skin and soft tissue impacts (4)
Oral Doxycycline
Oral Co-trimoxazole
Clindamycin
Linezoid
392
Contraindication for Oral Doxycycline
Do not treat with cations e.g. Al causes chelation
393
Skin Infections: Staphylococcus aureus - Bactericidal options for MRSA
Vancomycin
Daptomycin
394
Skin Infections: Coagulase negative are normally commensal, however they may cause infection in what situations?
Implanted material as produces a biofilm e.g. joints, heart valves or IV catheters
395
Skin Infections: What bacteria causes UTIs in women of child bearing age?
Staphyloccus saprophyticus
396
Skin Infections: Streptococcus - Gram staining
Gram positive cocci in chains
397
Skin Infections: Streptococcus - Survival in oxygen characteristics
Aerobic and facultatively anaerobic
398
Skin Infections: Beta Haemolytic Streptococci - Produces what toxin?
Haemolysin
399
Skin Infections: Beta Haemolytic Streptococci - Group A cause what?
Throat and severe skin infections
400
Skin Infections: Beta Haemolytic Streptococci - Group B cause what?
Meningitis in Neonates
401
Skin Infections: Streptococcus pyogenes - Involved in what skin conditions?
Infected eczema
Impetigo
Cellulitis
Erysipelas
Necrotising fasciitis
402
Skin Infections: Alpha haemolytic streptococci - Examples (2)
Streptococci pneumoniae
Streptococci viridans
403
Skin Infections: Alpha haemolytic streptococci - Streptococcus viridans is. acommensal of what?
Mouth
Throat
Vagina
404
Skin Infections: Treatment of Streptococci pyogenes
Penicillin or Flucloxacillin
405
Leg Ulcers: What microorganisms of leg ulcers are worth treating?
Streptococcus pyogenes
Staphylococcus aureus
Beta Haemolytic Streptococci - Groups B, C and G
406
Leg Ulcers: What group of patients are anaerobes relevant to?
Diabetics - tells if there is dead tissue or gram negative bacteria
407
Fungal Skin Infections: Examples (3)
Candidiasis
Tinea
Pityriasis versicolor
408
Fungal Skin Infections: Candidiasis is common in what?
Skin fold infections
409
Meaning of Tinea
Ringworm
410
Ringworm of the scalp
Tinea capitis
411
Ringworm of the beard
Tinea barbae
412
Ringworm of the body
Tinea corporis
413
Ringworm of the hand
Tinea manuum
414
Ringworm of the nails
Tinea unguium
415
Ringworm of the Groin
Tinea cruris
416
Ringworm of the foot
Tinea pedis
417
Dermatophytes: How does the fungus enter the body?
Via abraded or soggy skin
418
Dermatophytes: Hyphae spreads into what?
Stratum corneum
419
Dermatophytes: What spreads into the stratum corneum?
Hyphae
420
Dermatophytes: Infects what tissue type?
Keratinised
421
Dermatophytes: Examples of areas impacted (3)
Skin
Hair
Nails
422
Dermatophytes: What is the cause of scaling?
Increased epidermal turnover
423
Dermatophytes: Following an inflammatory response what is invaded?
Hair follicles
Shafts
424
Dermatophytes: Why does it appear as a ring?
Lesion grows outwards. andheals in the centre
425
Fungal Skin Infections: Sources of infections (3)
Other infected individuals - antropophillic fungi
Animals
Soil - geophilic fungi
426
Fungal Skin Infections: 3 examples of causative organisms
Trichophyton rubrum
Trichophyton mentagraphytes
Microsporum canis
427
Fungal Skin Infections: Most common causative organism
Trichophyton rubrum
428
Fungal Skin Infections: Transmission of trichophyton rubrum
Human to Human Transmission
429
Fungal Skin Infections: Transmission of Trichophyton mentagraphytes
Human to Human Transmission
430
Fungal Skin Infections: Transmission of microsporum canis
Cats and Dogs
431
Fungal Skin Infections: Diagnosis
Utilise skin scrapings, nail clippings and hair samples
432
Fungal Skin Infections: Skin Sample Instructions
Take skin scrapings from the scaly edge of the lesion and send to pathology in a dermapak for microscopy and culture for 2 weeks
433
Fungal Skin Infections: Management of small areas of infected skin or nails
Clotrimazole cream
Amorolfine topical nail paint
434
Fungal Skin Infections: Management of scalp infections
Oral Terbinafine or Itraconazole
435
Candida Skin Infections: Mainly affect what areas? (4)
Under breasts
Groin areas
Abdominal skin folds
Nappy area of babies
436
Candida Skin Infections: Diagnosis
Swab for culture
437
Candida Skin Infections: Treatment
Clotrimazole cream
Oral Fluconazole
438
Parasitic Skin Infections: Scabies - Causative organism
Sarcoptes scabiei
439
Parasitic Skin Infections: Scabies - Norweigen Scabies
Chronic crusted scabies that is highly infectious
440
Parasitic Skin Infections: Scabies - Incubation period
6 weeks
441
Parasitic Skin Infections: Scabies - Clinical Presentation
Intensely itchy rash that affects the finger webs, wrists and genital area
442
Parasitic Skin Infections: Scabies - Management option (2)
Malathion Lotion - applied overnight and washed off the next day
Benzyl benzoate
443
Parasitic Skin Infections: Scabies - When to avoid Benzyl Benzoate?
In children
444
Parasitic Skin Infections: Lice - Causative organism of head lice
Pediculus capitis
445
Parasitic Skin Infections: Lice - Causative organism of body lice
Pediculus corporis
446
Parasitic Skin Infections: Lice - Causative organism of pubic lice
Phthirus pubis
447
Parasitic Skin Infections: Lice - Management
Malathion
448
Viral Skin Infections: Examples of causative organisms? (5)
Herpes Simplex Virus
Human Papilloma Virus
Pox Virus
Varicella Zoster Virus
Viral Exanthems
449
Viral Skin Infections: Examples of erythematous exanthema that starts on the face (3)
Measles
Rubella
Erythema Infectiosum
450
Viral Skin Infections: Examples. of erythematous exanthema that starts on the trunk (3)
Roseola
Scarlet Fever
Unilateral laterothoracic exanthem
451
Viral Skin Infections: Examples of Papulo-vesicular exanthema (2)
Chickenpox
Gianotti Crosti Syndrome
452
Viral Skin Infections: Example of Exanthema of the extremities
Hand Foot and Mouth Disease
453
COVID Rash: Appearance
Morbilliform rash - this looks similar to measles
454
Infection Control in Dermatology: What situations require single room isolation?
Group A Strep Infection
MRSA infections
Scabies patients
455
Infection Control in Dermatology: What control is required for Norweigan Scabies?
Long-sleeved gowns
456
Pruritus
An unpleasant poorly localised non-adapting sensation that provokes the desire to scratch
457
Where is the itch sensation processed by?
Forebrain and Hypothalamus
458
What nerves carry the itch sensation?
Unmyelinated C fibres
459
Where do the nerves subserving the itch and pain sensation originate in the skin?
Epidermis
460
The itch sensation uses what CNS tract?
Lateral Spinothalamic Tract
461
Pre-formed Mast Cell Products (3)
Proteases
Heparin
Histamine
462
Newly Formed Mast Cell Products (3)
Prostaglandin D2
Leukotrienes C4, D4 and E4
Platelet Activating Factor
463
Itch: Pruitoceptive is usually associated with what?
Inflammation or Dryness
464
Itch: Psychogenic aetiology
Pscyhological cause with no CNS damage
465
Itch: Examples of Pruitoceptive causes (5)
Asteatotic Eczema
Insect bite reactions
Lichen plants
Chronic plaque psoriasis
Prurigo nodularis
466
Lichen plants cause an itch how?
Associated with Hepatitis C
467
Asteatotic Eczema
Direct exposure of itch-associated unmyelinated C fibres in the bases of microfissures and inflammation with release of mediators in the skin
468
Itch: Examples of a neuropathic cause of itch
Herpes Simplex Virus
469
Itch: Examples of Itch Managements (5)
Sedative anti-histamines
Emollients e.g. methanol cooled
Anti-depressants
Phototherapy
Opiate Antagonists
470
Itch: When are non-sedative anti-histamines not used?
When excess histamine is in the skin
471
Itch: Examples of Anti-depressants used for management
Doxepin
SSRIs
472
Itch: Example of an opiate antagonist used for management
Ondansetron
473
Hyperkeratosis
Increased thickness of the keratin layer
474
Parakeratosis
Persistence of nuclei in the keratin layer
475
Acanthosis
Increased thickness of the epithelium
476
Papillomatosis
Irregular epithelial thickening
477
Spongiosis
Oedema fluid goes between squares appear to increase the prominence of intercellular prickles
478
4 Main reaction patterns of inflammatory skin disease
Spongiotic Intraepidermal Oedema
Psoriasiform elongation of the rete ridges
Lichenoid-basal layer damage
Vesiculobullous blistering
479
Example of spongiotic intraepidermal oedema
Eczema
480
Example of psoriasiform elongation of the rete ridges
Psoriasis
481
Examples of lichenoid-basal layer damage (2)
Lichen Planus
Lupus
482
Where can skin tumours arise from? (5)
Epidermis
Melanocytes
Dermis
Appendages
Lymphoid elements
483
Oncogene
Overactive form of a gene that positively regulates cell deivision and therefore drives tumour formation when activity or copy number is increased
484
Proto-oncogene
Normal, not yet mutated form of an oncogene
485
Tumour suppressor
Inactive or non-functional form of a gene that negatively regulates cell division
486
Oncogenic Ras Signalling
In the absence of Growth Factor, Ras is still active to cause cell division and proliferation
487
Normal p53 function
In the presence of DNA damage, p53 is activated to halt the G1 checkpoint to repair DNA or trigger apoptosis
488
Oncogenic p53
In the presence of DNA damage, p53 cannot bind to DNA therefore progresses through the cell cycle
489
UV: wavelength of UVC
200-290nm
490
UV: wavelength of UVB
290-320nm
491
UV: wavelength of UVA
320-400nm
492
UV: Which is the highest exposure?
UVA
493
UV: UVA - How does this cause cancer?
Causes indirect DNA damage via oxidative damage
494
UV: UVA - causes damage to what skin structures?
Collagen
Elastic Fibres
495
UV: UVB - How does this cause cancer?
Direct DNA damage
496
UV: UVB - When are we most at risk?
When the sun is overhead
497
UV: UV exposure has what property?
Immunosuppressive
498
UV: UVB - Induces the secretion of what from where?
IL-10 from keratinocytes
499
UV: UVB - Causes a reduction in function of what cells of the epidermis?
Langerhan Cells - reduced APC function
500
UV: UVB - Causes a reduction in function of what cells of the dermis?
Dendritic Cells
501
DNA Damage: Two major types of UVB-induced DNA lesions
Cyclobutane Pyrimidine Dimers
Pyrimidine-Pyrimidone (6-4) Photo Products
502
DNA Damage: UVB-induced DNA lesions are formed how?
Covalent bonding between adjacent pyrimidines of the same DNA strand
503
Examples of acute skin effects of UV (2)
Erythema
Immunosuppression
504
Chronic skin effects of UV (2)
Photoageing
Photocarcinogenesis
505
Indications for skin biopsy (2)
Rash
Tumour of the skin
506
Dermoscopy function
Recognises morphological structures not visible to the eye to aid diagnosis
507
5 layers of the scalp
Skin
Connective Tissue
Aponeurosis
Loose Connective Tissue
Periosteum
508
What is the sensory nerve to the face?
Trigeminal Nerve
509
What are the three divisions of the Trigeminal Nerve?
V1 - Opthalamic division
V2 - Maxillary
V3 - Mandibular
510
How do you assess the sensory function of the face?
Ask the patient to close their eyes
Gently brush the skin in each dermatome with a fine tip of cotton woolAsk the patient where they feel sensation - compare the two sides
511
What impacts can fracture of the lateral aspect of the mandible have?
Damage V3 supply to the chin and lower limb to make them numb
512
What nerve supplies the muscle of the face?
Facial (VII) Nerve
513
How is the Facial nerve assessed?
Get. thepatient to frown, close their eyes and smile
Then get them to puff out their cheeks - if the sphincter is intact there will be no air leakage from the mouth
514
Anaesthesia: What are the 4 main options?
Topical
Local infiltration
Nerve block
Field block
515
Anaesthesia: What type of anaesthetic is Lignocaine?
Amide type
516
Anaesthesia: Lignocaine excretion is reduced in what patients?
Liver, Renal and Cardiac failure patients
Young
Elderly
517
Anaesthesia: Impact of adrenaline?
Prolongs anaesthesia and reduced bleeding
518
Anaesthesia: Maximum safe dose of Lignocaine
50ml 1% Lignocaine with adrenaline
519
Anaesthesia: Avoid adrenaline where?
Fingers and Toes
520
Anaesthesia: Avoid in patients with what?
Cardiac disease
On psychotropic drugs
521
When may electrosurgery be used?
Haemostasis
Treatment of minor skin lesions
