9. Wound Healing Flashcards
How long does it take for fascia to reach 60% strength?
a. 6 weeks
b. 10 weeks
c. 14 weeks
d. 18 weeks
C 14
How much strength does fascia have 7 days after closure?
a. 0%
b. 10%
c. 20%
d. 30%
A 0%
How long does it take for the urinary bladder to reepithelialize?
a. 2-4 days
b. 3-5 days
c. 4-6 days
d. 5-7 days
A 2-4
At what point is a urinary bladder 100% of its pre-injured state?
a. 14 days
b. 21 days
c. 28 days
d. 35 days
B 21d
What level of contamination is not recommended for primary closure?
a. 10^3 bacteria per gram
b. 10^5 bacteria per gram
c. 10^7 bacteria per gram
d. 10^9 bacteria per gram
B 10^5
leads to a 50-100% rate in wound infection
In clean contaminated wounds in patients with endocrinopathies, what is the increased risk for post-operative infection?
a. 5.5 x
b. 6.2 x
c. 8.2 x
d. 10.5 x
C 8.2
Name the phases of wound healing
Inflammation
Proliferation
Maturation
Define the following:
Autocrine
Paracrine
Juxtacrine
A = production of signaling molecule that act on on that cell or cells of the same type
P= production of signaling molecules that acts on a different but local cell types
J=contact-dependant signaling
Which is true concerning the hemostasis phase of wound healing?
A When epidermis is disrupted, keratinocytes release IL-10 which is the earliest signal in wound healing.
B Intense arteriole and capillary vasoconstriction occurs, which can prevent hemorrhage in arterioles up to 3 mm (if transversely lacerated)
C Platelets are activated as they bind to exposed type III and type IV collagen
D Thromboxane A2 is released from platelets, which is a potent vasoconstrictor and augments platelet aggregation by increasing expression of GPIIb/IIIa on the cell membrane of platelets
A IL-1
B Up to 5 mm in diameter
C Platelets are activated as they bind to exposed (Type IV and V collagen)
D TRUE
- After phagocytosis of a pathogen, __________ uses oxygen as a substrate to catalyze the formation of bactericidal superoxide (within the neutrophil)
NADPH
Which of the following is true?
A Unwounded dermis contains 20% type I and 80% type III collagen, which is reversed in initial wound healing
B TGF-Beta increases synthesis of type I collagen and decreases MMP production
C Granulation tissue is composed of macrophages, platelets, and hyaluronic acid
D Tropocollagens are formed inside the cell and then exported out for collagen fiber formation
A 80% type I and 20% type III
B TRUE: peaks 7-14 days after wounding
C fibrolasts, collagen, HA, and other matrix components
Dpro-alpha chains → triple helix → –ECM– → procollagen to tropocollagen → fibrils → fibers
Which of the following is true?
A Myofibroblasts orient perpendicular to lines of tension after day 6
B New epithelium will be hirsute after establishing itself over a granulation bed
C Contracture occurs when epithelial tissue persists where it shouldn’t
D The tensile strength of a skin scar is 70-80% of normal tissue, and will by 10% type III collagen
A linearly with lines of tension after 6; increases during following 2 weeks, will regress when tension/mechanical load decrease
B not
C Contracture occurs when mechanical load endurs and fibroblasts and myoblasts persist, continue to produce collagen, and contract
D TRUE
T/F Gastrointestinal submucosa is the holding layer and contains 68% type I, 20% type III, and 12% type V collagen
True
Just like in the skin, GI fibroblasts produce collagen (Type I and III) and elastin in the proliferative phase
False: UNLIKE the skin, GI fibroblasts AND SMOOTH MUSCLE CELLS synthesize collagen (Type I and III AND V) and elastin in the proliferative phase
When partial pressure of oxygen is below 40 mm Hg, mature collagen formation, angiogenesis and epithelialization will be impaired.
False: When partial pressure of oxygen is below 40 mm Hg, mature collagen formation FAILS, and PaO2 BELOW 10 mm HG → angiogenesis and epithelialization will be impaired.
A small intestinal incision may decrease 70% in strength by day 2 after surgery, largely due to the activity of collagenase
True
Which of the following is true regarding specific tissue healing
A Fascial sutures should be placed a minimum of 5mm from the wound edge and outside the active inflammation zone
B Once injured bladder mucosa reepithelializes in 2-4 days
C Bladder collagen synthesis reaches a peak at 3 days following injury
D The bladder regains 85% of its unwounded strength within 21 days
A min 3mm
B true
C 5 days
D 100%
At how many days post-operatively was the breaking strength of linear wounds found to be significantly greater in dogs compared to cats? A 5 days B 7 days C 10 days D 21 days
B 7
Which of the following is false regarding impaired wound healing
A Companion animals which habitually smoke cigarettes or are alcoholics will have impaired wound healing
B No reports in veterinary medicine have directly linked diabetes mellitus with clinically delayed wound healing
C If bacterial contamination is greater than 10^3 per gram of tissue, closure will result in an incidence of infection between 50-100%
D Neutropenia has been shown to delay wound healing
C 10^5
