tissue reponse to injury Flashcards
signs of inflammation
redness swelling tenderness increase temperature loss of function
chemical mediators
histamine, leukotrienes and cytokines
inflammation response phases
inflammation: day 1-4
fibroblastic repair phase: day 4 to week 6
maturation-remodling phase: 4 weeks to 3 years
histamine
released from the injured mast cells, causes vasodilation and increased cell permeability, owing to a swelling to endothelial cells and then separation between the cells
margination
leukotrienes and prostaglandins are responsible for margination: leukocytes (neutrophils and macrophages) adhere along the cell walls this will increase cell permeability affecting the passage of fluid, proteins and neutrophils though cell walls
diapedisis
movement of white blood cells OUT of small arterial vessels
exudate
accumulation of fluid that penetrates through vessel walls into joining extravascular space
neutrophils
a type of white blood cell that engulf invading microbes and contributes to the nonspecific defences of the body against disease
phagocytes
a type of white blood cell that ingests invading microbes
vasoconstriction
narrowing of blood vessels
inflammation response sequence
- injury to cell
- chemical mediators liberated (histamine, leukotrienes and cytokines)
- vascular reaction (vasoconstriction, vasodilation and exudate creates stasis)
- plateelts and leukocytes adhere to vascular wall
5 phagocytosis - clot formation
blood clot coagulation
thromboplastin prothrombin thrombin fibrinogen insoluble fibrin clot
collagen
structural protein found in the skin and connective tissue
type 1: found in skin, fascia, tendon, bone, ligaments, cartilage, and interstitial tissues (*found most in fibroblastic repair phase)
type 2: found in hyaline cartilage and vertebral disks
type 3: found in skin, smooth muscle, nerves and blood vessels (less tensile strength)
granulation tissue
fibroblasts, collagen and capillaries
extracellular matrix
collagen, elastic, ground substance, proteoglycans, glycosaminoglycans
maturation - remodling phases
a realignment or remodeling of the collagen fibers that make up scar tissue according to the tensile forces to which that scar is subjected
fibroblastic repair phase
along with increased oxygen delivery comes an increase in blood flow, which delivers nutrients essential for tissue regeneration in the area. The formation of a delicate connective tissue called granulation tissue occurs with the breakdown of the fibrin clot. granulation consists of fibroblasts, collagen and capillaries.
factors that impede healing
extent of injury (micro/macro tears) edema hemorrhage poor vascular supply separation of tissue muscle spasm atrophy corticosteriods kelod/hypertrophic scars infection humidity/climate/oxygen tension health/age/nutrition
ligament healing
- immediately after injury, ~72 hrs thee is a loss of blood from damaged vessels and attraction of inflammatory cells
- next 6 weeks, vascular proliferation w/ new capillary growth begins to occur along with fibroblastic activity, forming a fibrin clot
- gradually there is a decrease in fibroblastic activity, decrease in vascularity, and max increas in collagen density of a scar
- maturation of a scar may require at least 12 mos
myelinated axon
transmission of action potential travels- acts as a catalyst to make these signals travel quicker
schwann cell
supporting cells of the peripheral nervous system responsible for the formation of myelin
NSAIDS
nonsteroidal antiinflammatory drugs
therapeutic modalities
machines, devices, or substances that are used to enhance recovery from an injury
*heat facilitates an acute inflammatory response and cold slows down the inflammatory response
bone healing
- blood vessels are broken at the fracture line, the blood clots and forms hematoma
- blood vessels grow into the fracture and fibrocartilage soft callus forms
- fibrocartilage becomes ossified and forms a bony callus made up of spongy bone
- osteoclasts remove excess tissue from the bony callus and the bon eventually resembles its original appearance