Final answer:
The majority of salivary glands are activated by parasympathetic nervous system stimulation, which keeps the mouth moist and aids in digestion and oral health. Salivation can increase in response to food stimuli and decrease due to sympathetic stimulation during stress.
Step-by-step explanation:
The majority of salivary glands are activated by the parasympathetic nervous system, which is a part of the autonomic nervous system responsible for controlling the body's unconscious actions. Parasympathetic stimulation ensures that a comfortable level of saliva is maintained in the mouth, assisting with speaking, swallowing, and general oral health.
Saliva production can be increased by sensory stimuli such as the sight, smell, or taste of food, and can even occur when thinking about food. Sympathetic stimulation, on the other hand, decreases saliva production during stress or anxiety, leading to a dry mouth condition known as xerostomia.
Saliva contains several important components such as mucus, immunoglobulins, lysozymes, salivary amylase, and lipase, all of which contribute to the initial stages of digestion, oral health, and the breakdown of food components like starches and fats.