Why is it that the aroma of freshly brewed coffee makes your mouth water and stomach rumble Explain this reaction in terms ANS activity?
Aroma of freshly brewed coffee
The aroma of freshly brewed coffee is a delightful sensory experience that can evoke feelings of comfort and relaxation.
It can also trigger a physiological response in the body known as cephalic phase response ,which is an anticipatory digestive reaction to the ingestion of food. This response is mediated by the activity of the autonomic nervous system (ANS).
The ANS has two divisions:
- Sympathetic nervous system (SNS) ,which is responsible for the body's "fight or flight" response.
- Parasympathetic nervous system (PNS), which controls the body's "rest and digest "functions.
When you smell the aroma of freshly brewed coffee, the sensory information is transmitted to the olfactory bulb in the brain. The olfactory bulb then sends signals to the limbic system, a complex network of brain structures involved in memory, emotions, and motivation.
The limbic system, in turn, stimulates the vagus nerve, a major component of the PNS, to initiate the cephalic phase response.
The cephalic phase response includes several physiological changes, such as:
- Increased salivation: The aroma of coffee stimulates the production of saliva, a watery fluid that helps to break down food and begins the process of digestion
- Increased stomach acid production: The smell of coffee triggers the release of gastrin, a hormone that promotes the secretion of stomach acid. Stomach acid is essential for the digestion of proteins.
- Relaxation of the esophageal sphincter: The esophageal sphincter is a muscular valve that separates the esophagus from the stomach. The aroma of coffee causes the esophageal sphincter to relax, allowing stomach juices to enter the esophagus and mix with the food that is being swallowed
- Gut contraction: The smell of coffee stimulates the release of hormones that promotes gut contraction. This helps in moving food through the digestive tract and ensuring proper digestion.
The cephalic phase response is an important mechanism that prepare the body for digestion. The increased saliva, stomach acid, and gut contraction all contribute to the efficient breakdown of food and absorption of nutrients.
So the next time you enjoy the aroma of freshly brewed coffee, take a moment to appreciate the fascinating interplay between your senses and your digestive system.