Answer to Question 1
Changes in the immune system have important implications as people age. Older adults become more prone to serious consequences of illnesses, such as those caused by viruses, that are easily defeated by younger individuals. Older adults do not seem to benefit as much as younger people from immunizations. Also, the rates of various forms of leukemia, as well as other cancers, increase with age. In addition, the immune system may begin attacking the body in a process called autoimmunity.
Autoimmunity results from an imbalance of B- and T-lymphocytes, giving rise to autoantibodies. Autoimmunity causes several disorders, including rheumatoid arthritis.
Answer to Question 2
There are three major types of cells in the immune system that form a network of interacting parts: cell-mediated immunity (consisting of cells originating in the thymus gland, or T-lymphocytes); immunity based on the release of antibodies in the blood, such as those acquired from immunization or manufactured in bone marrow (B- lymphocytes); and nonspecific immunity (monocytes and polymorphonuclear neutrophil leukocytes).
The formation of a chimeric gene that is found in people with certain forms of leukemia.
As a result of this change, deoxyhemoglobin S
Monstrous people from distant lands depicted in a fifteenth-century European woodcut.
In many work settings, middle-aged people demonstrate generativity by serving as mentors for their ...
By 2100, significant change will be in the far northern latitudes, parts of Asia, and Sub-Saharan
Sensory systems and Endocrine system