MODULE SUPPLEMENT: IMMUNE SYSTEM
Acid Contents of the Stomach

Early data suggested that older adults experienced achlorhydria or at least diminished acidity with age. Recent studies suggest this is NOT true in healthy individuals without concurrent gastric problems.

It may be true, however, that older adults are more predisposed to having less efficient acid secretion with age and may be more predisposed to achlorhydria and atrophic gastritis, which will decrease this line of defense, however, it's not a "normal" change that automatically occurs with age.

Cilial Action and Cough Reflex (Lung)

Cilial action of the lung and cough reflex--these tend to be decreased with decreased lung elastic recoil and other pulmonary alterations and insults (see the pulmonary module for discussion on age changes in the lung). These changes alter pulmonary clearance and can predisposed to aspiration and pneumonia.

Chemical/Substances

Chemicals or substances in the blood and cells attach to foreign organisms or toxins and destroy them. They are directly involved with the specific immune system.