week 19 (skin microbial interactions and wound healing)

Question 1

within skin environments, what substance disrupts the balance

Answer 1

antibacterial wash

Question 2

microbes colonise moist and oliy skin regions around what structure

Answer 2

hair follicles

Question 3

_____prevents bacterial penetration to the dermis

Answer 3

keratinisation

Question 4

gland secretions contain defences including slightly acidic sweat and what?

Answer 4

antimicrobial peptides

Question 5

damaged skin gives opportunities for microbes to invade what layers (3)

Answer 5

hypodermis
subcutaneous fat layer
blood stream

Question 6

damaged skin gives opportunities for microbes to invade the hypodermis, subcutaneous fat layer and blood stream where they can cause what

Answer 6

serious illness

Question 7

what characteristics do Langerhans cells possess

Answer 7

motile dendritic cell in epidermis
antigen presenting: phagocytose pathogens and present antigenic surface proteins to T cells

Question 8

what characteristics to Keratinocytes possess

Answer 8

possess toll like receptors (TLRs)
detect pathogens
release cytokines to induce Langerhans and T cell movement to site of infection

Question 9

what are characteristics of dermal dendritic cells, macrophages and innate lymphoid cells (ILC )

Answer 9

antigen presenting in dermis
ILCs orchestrate immune responses among T cells and can suppress attack of helpful bacteria

Question 10

how many phases are there in the skin wound healing response

Answer 10

3

Question 11

what are the 3 phases in the skin wound healing response

Answer 11

Inflammatory phase
Proliferative Phase
Remodelling Phase (maturation phase)

Question 12

when does the inflammatory phase occur in the wound healing response

Answer 12

first 48 hours

Question 13

what occurs in the inflammatory phase within the skin wound healing response

Answer 13

release of inflammatory cytokines

Question 14

within the inflammatory phase in the skin wound healing response the release of inflammatory cytokines promote what

Answer 14

promotes immune cell chemotaxis (macrophage, T cells) to site of wound
accumulation = pus

Question 15

what is the cell of origin for EGF

Answer 15

platelets, macrophages

Question 16

what is the cell of origin for FGF

Answer 16

macrophages, mast cells, T lymphocytes, endothelial cells

Question 17

what are the cells of origin for IFN (alpha, beta, and gamma)

Answer 17

lymphocytes, fibroblasts

Question 18

what are the cells of origin for Ils (1, 2, 6, 8)

Answer 18

macrophages, mast cells, keratinocytes, lymphocytes

Question 19

what are the cells of origin for KGF

Answer 19

fibroblasts

Question 20

what are the cells of origin for PDGF

Answer 20

platelets, macrophages, endothelial cells

Question 21

what are the cells of origin for TGF-alpha

Answer 21

macrophages, T lymphocytes, keratinocytes

Question 22

what are the cells of origin for TGF-beta

Answer 22

platelets, T lymphocytes, macrophages, endothelial cells, keratinocytes

Question 23

whar are the cells of origin for thromboxane A2

Answer 23

destroyed wound cells

Question 24

what are the cells of origin for TNF

Answer 24

macrophages, mast cells, T lymphocytes

Question 25

in the skin wound healing response what is the length of time for the proliferative phase

Answer 25

first 1-2 weeks

Question 26

in the skin wound healing response, within the proliferative phase, where do growth and division of epithelial cells come from

Answer 26

stratum basale (epithelization)

Question 27

in the proliferative phase, where does angiogenesis occur

Answer 27

dermis

Question 28

in the proliferative phase, what occurs in the dermis

Answer 28

angiogenesis

Question 29

in the proliferative phase where does fibroblast proliferation occur

Answer 29

dermis

Question 30

in the proliferative phase, fibroblast proliferation in dermis deposits what

Answer 30

collagen

Question 31

in the proliferative phase, fibroblast proliferation in dermis deposit collagen to create what

Answer 31

supporting matrix over which the epidermal keratinocytes can grow

Question 32

in the proliferative phase, fibroblasts produce what

Answer 32

dermal granulation tissue

Question 33

within the skin wound healing response, how long does the remodelling phase last

Answer 33

2 weeks -> months/years

Question 34

in the remodelling phase, there can be a result of scarring, why?

Answer 34

type III collagen becomes replaced by Type I

Question 35

in the remodelling phase, cross linking of collagen helps what

Answer 35

increases tensile strength

Question 36

in the remodelling phase, what increases tensile strength

Answer 36

cross linking of collagen

Question 37

what are antibiotic peptides produced by

Answer 37

skin epithelial cells

Question 38

Beta defensins form part of what

Answer 38

innate immune response mechanism

Question 39

permeabilize bacterial outer wall causes what

Answer 39

lysis

Question 40

staphylococcus epidermidis is gram _____

Answer 40

positive

Question 41

staphylococcus epidermidis is ______ and ______ coloniser of what

Answer 41

permanent and ubiquitous colonsier of human skin

Question 42

staphylococcus epidermidis resists colonisation of

Answer 42

other bacteria

Question 43

staphylococcus epidermidis has mechanisms for what

Answer 43

host immune evasion

Question 44

what skin condition causes boils and abscesses

Answer 44

staphylococcus aureus

Question 45

what skin condition (bacteria) colonises the human skin, lung, and gut

Answer 45

staphylococcus aureus

Question 46

what does staphylococcus aureus secrete (name as many as possible (7))

Answer 46

coagulase (blood clots) hyaluronidase (breaks down desmosomes junction between cells) staphylokinase (degrades fibrin and basement membrane attachments lipase(degrades protective sebaceous oils) lactamase (degrades penicillin) catalase (resists reactive oxygen species attack) virulence factors (causes rapid colonisation)

Question 47

staphylococcus aureus infection of the skin (whats the name)

Answer 47

folliculitis

Question 48

what does quorum sensing mean

Answer 48

homeostatic mechanism involving released peptide signals (autoinducer peptides, AIPS) that keep bacterial population stable

Question 49

acne is an anearobic bacterium found where

Answer 49

in dermal pores and hair follicles

Question 50

what is the nutrient source for acne (Propionibacterium acnes)

Answer 50

sebum, shed keratin

Question 51

elevated sebum secretion is increased by what

Answer 51

induced by sex hormones follicle blockage provides perfect growth conditions

Question 52

what is sebum produced by

Answer 52

holocrine secretion

Question 53

malassezia is found where

Answer 53

common fungal commensal of human skin

Question 54

malessezia is part of what

Answer 54

normal flora of the epidermis

Question 55

where is demodex mites found

Answer 55

normal skin fauna found in hair follicles on the cheeks

Question 56

mites ad rosacea called what

Answer 56

demodex mites

Question 57

what is rosacea

Answer 57

inflammation and thickening of the skin