Terminology 2

• A


  Without, example – alexia (without words)
• Trophy


  Lack of nourishment or food
• Hyper


  More than, greater than, beyond
• Meta


  Mould/form into new shape
• Dys


  Poor, not as 'normal', 'bad'
• Dynamic systems


  • Always trying for stable internal environment
  • Within a normal range of function, example – blood pH normal range = 7.35-7.45
  • The body tries to maintain balance/steadiness by correcting any fluctuations/deviations from normal
  • Example – increasing heart rate to increase blood flow, movement of white blood cells to areas of infection
  • Small fluctuations can be significant and can lead to pathophysiology
• Bleeding injuries


  1. Break in blood vessel = blood escapes

  2. Clotting begins using platelets

  3. Blood loss stemmed = return to homeostasis

  4. Healing occurs

  5. ***if blood doesn't clot could be haemophilia, therefore cannot return body to homeostasis without intervention or medication
• Changes to any body system can affect homeostasis
• Altered cell biology can be a result of adaptation, injury, and ageing
• Adaptation


  • Can be pathological or non-pathological
  • Non-pathological = uterine wall changes to accommodate growing foetus
  • Pathological = enlarging of heart walls due to constant high blood pressure (good short term fix, harmful long-term)
• Injury


  • Can be reversible or irreversible
  • Reversible = burning epithelial tongue cells from hot coffee
  • Irreversible = neurological cell death post-brain injury
• Ageing


  • Cells function less efficiently
  • Slower recovery from injury
• Atrophy


  Decrease in cell size and function
• Hypertrophy


  Increase in cell size of individual cells
• Hyperplasia


  Increase in number of cells due to increased cell division
• Metaplasia


  Reversible replacement of one mature cell type by another, often less specialised cell type
• Dysplasia


  Abnormal changes in size, shape, structure and organisation of mature cells – precurosr to cancer
• Atrophy


  • Most common in skeletal muscle, the heart, secondary sex organs and brain
  • Physiological atrophy is normal developmental process, example – thymus gland shrinks from childhood to adulthood
  • Pathological atrophy is a result of the lack of workload (use), blood supply, nutrition, hormones, nervous system stimulation
  • Example – Muscular atrophy following periods of non-use, example – after spinal cord injury/nerve damage, fractures, prolonged bed rest
• Hypertrophy


  • Heart and kidney very prone to enlargement
  • Physiological hypertrophy is muscular hypertrophy of body builders, the enlargement of breasts during pregnancy
  • Pathological hypertrophy is faulty heart valves causing the heart muscle to overwork to be able to pump blood and thus increases in size
  • Example – hypertrophic enlargement of heart valve, enlargement of left ventricular walls compared to normal ventricle
• Hyperplasia


  • Example – as a response to injury such as the removal of part of the liver, it regenerates to a certain degree (physiological hyperplasia)
  • Example – prostate enlargement causes urethra blockage (pathological hyperlasia)
• Metaplasia


  • Example – lung epithelial cells replaced by squamous cells that don't have specialised functions - secretion occurring in smokers
• Dysplasia


  • Example – epithelial cells in the cervix
• Problems with oxygen entering the blood

  • Respiratory diseases, example – COPD, asthma
  • Blockage of the upper airway, no air to lungs
  • Altitude, low oxygen available
• Insufficient transportation of oxygen

  • Decrease in haemoglobin (example - anaemia)
  • Decreased production of red blood cells (example - anaemia, leukemia) - both result in reduced oxygen 'carrying' capacity by blood
  • Decreased pumping ability of the heart (example – cardiomyopathies) - cant efficiently pump blood through arteries to required places
• Most common cause for hypoxia is ischaemia - restricted blood supply to the organs due to barriers such as blood clots, arteriosclerosis, emboli's
• Toxicity


  • Examples – cyanide, carbon monoxide, alcohol, recreational and prescription drugs, chemotherapy
• Necrosis


  Cell death
• Types of necrosis


  • Coagulative necrosis – heart, kidneys and adrenal glands
  • Liquefactive necrosis – brain
  • Caseous necrosis – lungs, example – TB
  • Fat necrosis – wherever fat occurs
  • Gangrenous necrosis – dry and wet types, mainly in limbs, blockages of arteries
• Coagulative necrosis


  • When many cells undergo necrosis at once, then definable patterns of necrosis are produced, depending upon the nature of the injury, the type of tissue, and the length of time. This is an example of coagulative necrosis. This is the typical pattern with ischemia and infarction (loss of blood supply and resultant tissue anoxia). Here, there is a wedge-shaped pale area of coagulative necrosis (infarction) in the cortex of the kidney
• Liquefactive necrosis


  • Liquefactive necrosis of brain post-blood clot
• Caseous necrosis


  • Caseous necrosis of the lung due to Tuberculosis, containing the yellow-white 'cheesy' debris of soft and granular necrotic, partly digested cells
• Fat necrosis


  • White chalky deposits that look like soap – saponification
• Gangrenous necrosis


  • Death of tissue, this is due to diabetic neuropathies, dry gangrene, hypoxia, and bacterial infection