Old age begins in the mid-60s and lasts until the end of life. Most people over 65 have retired from work, freeing up their time for hobbies, grandchildren, and other interests. Stamina, strength, reflex time, and the senses all decline during old age, and the number of brain cells decreases as well. The immune system becomes less efficient, increasing the risk of serious illnesses such as cancer and pneumonia. Diseases such as Alzheimer’s disease that cause loss of mental function also become more common.
Dr. Smith is examining the medical records of two of her patients to get a better understanding of their medical history, what factors contribute to the difference in health between the two patients, and what factors contribute to their health at present. Patient A is a 66 year old male and Patient B is a 22 year old male.
Which patient will likely have fewer brain cells, Patient A or Patient B?