Inflammation & Healing 2 Flashcards
Where is histamine released from?
mast cells
Where is NO released from?
endothelium
Where is serotonin released from?
platelets
What mediators are involved in vasodilation?
histamine, prostaglandins, NO
What mediators are involved in increased vascular permeability?
histamine, serotonin, leukotrienes, bradykinin
What mediators are involved in endothelial activation?
IL-1, TNF
What mediators are involved in chemotaxis?
complement, bacteria components, cytokines, leukotriene B4
What mediators are involved in tissue damage?
neutrophil granule contents, ROS, NO
What mediators are involved in pain?
prostaglandins, bradykinin
What mediators are involved in fever?
IL-1, IL-6, TNF, prostaglandins
What enzyme do corticosteroids inhibit?
Phospholipases which converts phospholipids into arachidonic acid
What do non-steroidal anti inflammatory drugs inhibit?
Cyclooxygenase which converts arachidonic acid to prostaglandins
What are the two main products of arachidonic acid?
Prostaglandins and leukotrienes
What enzyme converts arachidonic acid to leukotrienes?
Lipoxygenase
What happens to exudate after acute inflammation?
The fluid drains to the lymph and the neutrophils and monocytes are phagocytosed by macrophages
What are the main outcomes of acute inflammation?
resolution (no scar tissue), healing by repair, chronic inflammation
What are the components of granulation tissue?
Inflammatory cells (macrophages and lymphocytes), new blood vessels, fibroblasts, extracellular matrix, myofibroblasts
What is the role of macrophages in granulation tissue?
phagocytosing debris and releasing factors e.g. growth factors
What is the role of lymphocytes in granulation tissue?
developing an immune response
What is the role of myofibroblasts in granulation tissue?
To contract the wound
What are the features of a mature scar?
poorly cellular - most remaining cells are fibroblasts, poorly vascular - macroscopically looks white
How long does it take to form a mature scar?
6-8 weeks
What is transforming growth factor beta important for?
immune responses and inhibiting epithelial proliferation
What is healing by primary intention?
The healing of a narrow wound with closely opposed edges
What is healing by secondary intention?
The healing of a larger area e.g. an ulcer, infarct or burns
What is dehiscence?
Where the wound ruptures along a surgical suture
What is a keloid?
Proterburant masses of scar tissue - typically occurs in dark skin
What is contracture?
Fibrous tissue grows where it shouldn’t in wound healing
