How does food make your mouth water?
Even thinking about a delicious meal can get the saliva flowing. This video explains the chemical mechanisms behind drooling at the dinner table.
Sitting down to eat, or even thinking about your favourite food, can get you drooling. How?
The nerves that control saliva production are part of a reflex system. They fire without conscious thought and can be activated by smells, tastes and even the movement of jaw muscles.
When food is smelt, seen or even thought about, a signal is sent to your brain's primary salivary centres in the medulla oblongata. The brain releases neurotransmitters such as acetylcholine and norepinephrine which initiate nerve signals, telling the glands to produce saliva.
Major salivary glands are found near the upper teeth, under the tongue and on the floor of the mouth. Minor glands are locates in the lips, inner cheeks and other linings of the mouth and throat.
They can produce up to two litres of saliva a day, which moistens your mouth, protects your teeth from decay and, importantly, initiates digestion. It contains enzymes that start to break down food before it reaches your stomach.