21. What does the term “antibiotic” mean?

21. An antibiotic is a medicine that kills or stops the growth of bacteria. 22. The stomach lies in the upper part of the abdomen, mainly on the left side, below the diaphragm. 23. Food typically stays in the stomach for about 2 to 4 hours, depending on its composition. 24. The liver filters blood from the digestive tract, detoxifies chemicals, metabolizes drugs, and produces bile for digestion. 25. Immunity is the body's ability to resist and fight off infections, diseases, or other unwanted biological invasions. 26. Immunity is provided by the immune system, including white blood cells, antibodies, the lymphatic system, and organs like the spleen and bone marrow. 27. Fever is often considered the first symptom of many infectious diseases. 28. Atherosclerosis is a disease where plaque (fat, cholesterol, and other substances) builds up inside the arteries, causing them to narrow and harden. 29. Heart diseases are generally grouped into categories such as coronary artery disease, heart rhythm problems (arrhythmias), heart defects, heart valve disease, and heart muscle disease (cardiomyopathy). 30. Homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems, like body temperature or pH balance.