Cell death

• What is autophagy?


  • May prevent cell death
  • Digest intracellular structures (old organelles) (cleans cell)
  • e.g, digest old mitochondria via lysosome
• Why is cell death important?


  • Removes unwanted cells (important for growth, development & maintenance of body)
  • e.g, maintaining tissue size in adult while refreshing cells in small intestine
  • When cells damaged/infected, they die to ensure they don't threaten health of organism
• What is digit morphogenesis?


  Reforming shape of hand in embryos
• What is apoptosis?


  • Physiological programmed cell death
  • Cells shrink & condense, chromatin breaks up into fragments, cell surface changes so macrophage can detect it & engulf it
  • membrane still intact
  • requires energy
• What is necrosis?


  • Pathological cell death in response to acute insult (e.g, physical damage)
  • Cells burst, spilling contents over their neighbours & induce immune response
  • Membrane breaks