Chapter 4 - Altered Cellular and Tissue Biology Flashcards
When does cellular injury occur?
if a cell is unable to maintain homeostasis
What is the result of reversible cellular injury?
cells recover
What is the result of irreversible cellular injury?
cells die
Physiological Cellular Response
adaptive
Pathogenic Cellular Response
disease causing
What is cellular atrophy?
decrease in cellular size
What is cellular hypertrophy?
increase in cellular size
What is cellular hyperplasia?
increase in cellular number
What is cellular metaplasia?
replacement of one type of cell with another
What is cellular dysplasia?
deranged cellular growth
When does cellular metaplasia occur?
with chronic injury or irritation
What does “meta” mean?
after, behind
When does cellular dysplasia occur?
persistent severe injury or irritation
What does “dys” mean?
bad
What is the most common cause of cellular injury?
hypoxic injury
Ischemia
reduced or restricted blood flow leading to inadequate blood supply
What is the most common cause of hypoxia?
ischemia
What organelle is the main cellular consumer of oxygen?
mitochondria
What is the result of reduced oxygen to the mitochondria?
reduced ATP production resulting in reduced cellular energy and accumulation of H+
What can an accumulation of H+ in the mitochondria result in?
breakdown in the membrane leading to an increase intracellular H+ and loss of membrane potential
What does lost membrane potential lead to?
necrosis
Ischemia-Reperfusion Injury
additional injury caused by restoration of blood flow and oxygen
What are the mechanisms if ischemia-reperfusion injury?
oxidative stress, increased intracellular calcium, inflammation
Cellular response to hypoxic injury?
decrease in ATP leading to sodium-potassium pump and sodium-calcium exchange failure