Pathophysiology and Drug Action Exam 4 Flashcards
What is the first stage of healing after tissue injury?
-Hemostasis
-occurs in minutes
What is the second stage of healing after tissue injury?
-inflammation
-driven by platelet-derived mediators (redness, swelling, pain)
-occurs in hours
What is the third stage of healing after tissue injury?
-PROLIFERATION fibroblast secreted mediators signal cell proliferation to regenerate lost tissue; laying down type III collagen
-occurs over days
What is the fourth and final stage of healing after tissue injury?
-REMODELING type III collagen is replaced with type I collagen and tensile strength of the new tissue is increased
-occurs over weeks to months
What is the difference between tissue regeneration and tissue repair?
-tissue regeneration occurs when cells lost by injury are replaced by cells of the exact same type and function
-tissue repair occurs when regeneration is not possible and is replaced by cells that are not the same as the ones lost in injury. this results in scarring or fibrosis.
What are the factors that determine whether a tissue gets regenerated versus repaired?
-depends on the nature of the cells injured, extent of the injury, presence of ongoing inflammation, and the co-existence of underlying disease
What are the common outcomes of various signal transduction pathways of growth factors?
-change in gene expression
What are the two forms of the Extra-cellular Matrix and their key components?
-extracellular matrix and interstitial matrix
-integrins hold the epithelium to the basement membrane; serve as a reservoir for growth factors
-fibroblasts are connected to the ECM and work in fibrosis
What are the three key growth factors that regulate fibrosis?
PDGF (Platelet-derived growth factor)
TGFB (transforming growth factor)
FGF-2 (Fibroblast growth factor)
What are the three key elements of shock?
-life threatening condition
-circulatory failure
-inadequate oxygenation
What are the four main types of shock and their causes associated with them?
-distributive shock (sepsis, Anaphylaxis, Neurogenic)
-hypovolemic shock (Hemorrhage, Severe burns, severe vomiting, diarrhea)
-cariogenic shock (myocardial infarction, ventricular arrhythmia, cardiac myopathy, valvular disease)
-obstructive shock (cardiac tamponade, Pulmonary embolism, Pneumothorax)
What is the component of gram-negative bacteria that mediates septic shock?
endotoxin (LPS)
What is the role of adrenomedullin in modulating vascular function?
-when in the intravascular space, it enhances the endothelial barrier and reduces the movement of solutes out of the vascular space
-when in the interstitial space, it mediates the relaxation in vascular smooth muscle and causes vasodilation
what does edema mean?
-accumulation of fluid in interstitial space of body tissues
What are the primary drivers of fluid in and out of the vascular space?
hydrostatic and colloid osmotic pressure
Describe the mechanisms and common clinical causes of edema
-increased capillary permeability (cellulitis, sepsis, hypersensitivity reactions)
-Increased capillary hydrostatic pressure (compartment syndrome, chronic venous insufficiency, heart failure, renal failure, pregnancy)
-Decreased capillary oncotic pressure (protein deficient states, nephrotic syndrome, cirrhosis)
-Lymphatic obstruction (lymphedema) tumor, trauma, infection (filariasis)
What type of shock is associated with the triad symptoms of hypothermia, coagulopathy, and acidosis?
-Hypovolemic Shock