A channel for airflow through the nose. The walls of the nasal passages are coated with respiratory mucous membranes, which contain innumerable tiny hair-like cells that move waves of mucus toward the throat. Dust, bacteria, and other particles inhaled from the air are trapped by the mucus in the nose, carried back, swallowed, and dropped into the gastric juices so that any potential harm they might do is nullified. The organs of smell are made up of patches of tissue called olfactory membranes. The olfactory membranes are about the size of a postage stamp and are located in a pair of clefts just under the bridge of the nose. Most air breathed in normally flows through the nose, but only a small part reaches the olfactory clefts to get a response to an odor. When a person sniffs to detect a smell, air moves faster through the nose, increasing the flow to the olfactory clefts and carrying more odor to these sensory organs.
- Passive exercise
Movement of the body, usually of the limbs, without effort by the patient. The patient is passive.
- Passive immunity
Immunity produced by the transfer to one person of antibodies that were produced by another person. Protection from passive immunity diminishes in a relatively short time, usually a few weeks or months. For example, antibodies passed from the mother to the baby before birth confer passive immunity to the baby for the first 4-6 months […]
- Passive smoking
Inhalation of smoke that comes from someone else smoking. Passive smoking is associated with the same array of diseases as actual smoking, with an elevated risk of lung cancer and other diseases.
Pertaining to behavior in which feelings of aggression are expressed in passive ways as, for example, by stubbornness, sullenness, procrastination, or intentional inefficiency. The term passive-aggressive behavior was coined by military psychiatrists in a 1945 US War Department technical bulletin to describe soldiers who employed a mixture of passive resistance and grumbling compliance.
- Passive-aggressive personality disorder
A personality disorder characterized by passive-aggressive behavior. Passive-aggressive personality disorder is no longer recognized as a diagnosis by the American Psychiatric Association .