…stomach, whose complex work is under the control of what’s sometimes called “the little brain”, a network of neurons that line your stomach and your gut. Surprisingly, there are over 100 million of these cells in your gut, as many as there are in the head of a cat.
And all those neurons lining our digestive system allow it to keep in close contact with the brain in your skull, via the vagus nerves, which often influence our emotional state. For instance when we experience “butterflies in the stomach”, this really is the brain in the stomach talking to the brain in your head. As we get nervous or fearful, blood gets diverted from our gut to our muscles and this is the stomach’s way of protesting.
and a third in the heart:
After extensive research, Armour (1994) introduced the concept of functional ‘heart brain’. His work revealed that the heart has a complex intrinsic nervous system that is sufficiently sophisticated to qualify as a ‘l ittle brain’ in its own right.
The heart’s brain is an intricate network of several types of neurons, neurotransmitters, proteins and support cells similar to those found in the brain proper. Its elaborate circuitry enables it to act independently of the cranial brain – to learn, remember, and even feel and sense. The heart’s nervous system contains around 40,000 neurons, called sensory neurites (Armour, 1991).
Information from the heart – including feeling sensations – is sent to the brain through several afferents. These afferent nerve pathways enter the brain at the area of the medulla, and cascade up into the higher centres of the brain, where they may influence perception, decision making and other cognitive processes (Armour, 2004).
That’s got to be some example of science catching up with older knowledge. I’ll await your other posts with more info.