Notes of a High Distinction Student: Bachelor of Biomedical Science

How to Distinguish Between Hyperplasia, Hypertrophy, Necrosis, Atrophy & Apoptosis Topic 1 - Cellular Changes in Disease What is Hyperplasia? An INCREASE in the NUMBER of cells due to an adaptive change e.g. the removal of a kidney What is Hypertrophy? An INCREASE in the SIZE of cells due to an adaptive change e.g. half a heart not functioning What is Atrophy? A DECREASE in the SIZE of cells, failure to adapt to change, loos of cytoskeleton and organelles e.g. muscular dystrophy What is Metaplasia? One adult cell is replaced with a different adult cell   What is Dysplasia?  An abnormal change in size, shape and organisation (not adaptive)   What is Necrosis? Necrosis is cell death caused by injured cells, usually by enzymes or denatured proteins. Types of necrosis include  Coagulative, Liquefaction or Casseous Coagulative necrosis -  Occurs in the heart, kidney and adrenal glands. Results from ischemia or hypoxia caused by chemical

Cellular change in disease are often non-specific or adaptive changes to injury. Cellular disease can be identified if there are: External indicators Physical measurement changes Biochemical changes Changes in the pathology of the cell Cell damage depends on type of agent or stress, type and duration of injury or type of tissue involved. Cellular changes which are all adaptations to stressors include: Hypertrophy Atrophy Hyperplasia Metaplasia Dysplasia Handy Hint! How can you memorize the above?  MADHH ( MAD H airy H ead) M etaplasia, A trophy, D ysplasia, H ypertrophy, H yperplasia How does the lack of oxygen affect cells? Hypoxia is the lack of oxygen in cells which is the most common cause of cell injury and most commonly caused Ischemia (reduced blood supply) however can also be caused by any of the following: Decrease of oxygen in the air Loss of haemoglobin or loss of Hb (Haemoglobin) function Decrease