Units

• Antigens


  Foreign substances that invade the body and trigger an immune response. They can be proteins, polysaccharides, or other molecules found on the surface of bacteria, viruses, or other pathogens.
• Lactic acid

  A byproduct of anaerobic respiration in muscle cells, produced when there is not enough oxygen to support aerobic respiration. Accumulation of lactic acid can cause muscle fatigue and soreness.
• Anaerobic respiration

  A process of cellular respiration that occurs in the absence of oxygen, in which glucose is converted into pyruvate and lactic acid to generate ATP for energy.
• Ventricular systole


  The phase of the cardiac cycle where the ventricles contract and pump blood out to the body