major function of the immune system is defense against infection and
advancing age, the lymphatic system becomes less effective at combating
disease and fighting off infections. T and B cells are the primary
cells involved with immunity and attack specific invaders as they
penetrate mechanical, chemical, and other cellular barriers.
the cells responsible for cellular immunity and for coordination and
regulation of immunity, become less responsive. As a result, fewer T
cells respond to an infection or invasion by a pathogen.
the cells that produce antibodies, are also less responsive, so
antibody levels do not rise as quickly after an infection develops in
an elderly person. The net result is an increased susceptibility to
viral and bacterial infections.
reason, vaccinations for viruses like the flu are strongly recommended
for elderly people. In addition, the increased incidence of cancer in
the elderly reflects the fact that surveillance by the lymphatic system
declines, and tumor cells are not eliminated as effectively.
complementary forms of immunity rid humans of pathogens and cancer
cells: nonspecific (or innate) defenses and specific (or adaptive)
defenses. Nonspecific immunity provides a rapid but incomplete defense
against a variety of threatening agents until the slower, specific
immune response develops.
plays a factor in a healthy immune system as well. In both healthy and
nutritionally-deficient older adults, vitamin and other dietary
supplements enhance the response of the immune system resulting in
fewer days of infectious illnesses.
adults often experience loss and stress, and suppressed immunity has
been associated with bereavement, depression, and poor social support.
Maintaining an active social life and receiving treatment for
depression could boost the older adult's immune system.
are caused by the production of antibodies to a substance not normally
recognized as harmful in the average human body. For some reason, these
typically harmless substances trigger an immune reaction in susceptible
individuals thus eliciting a normal immune response after inhalation,
ingestion, or penetration through the skin.
so fun fact:
the US, infectious disease ranks 8th among most causes of death but
rises to rank 4th in persons over 65. Similarly, cancer incidence
increases exponentially after the age of 30. Many believe that immune
senescence and the decline in “immune surveillance”
contribute to these statistical increases.
so fun fact:
vaccines do not work as well in the immune system of older adults,
vaccinations for diseases such as influenza, pneumonia, hepatitis B,
tuberculosis, diphtheria, and tetanus have been found to reduce
mortality in the elderly and are still worthwhile.