The respiratory system takes in air starting from your nose and mouth, then sends it through a tube in your throat called the trachea, and then into your lungs. The trachea connects to the lungs by splitting into two tubes called bronchiole tubes, which eventually split into smaller and smaller tubes.
Causes and contributors of low Serotonin Levels and Deficiency. Serotonin is synthesized in the brain and body from tryptophan an amino acid. Tryptophan converts into 5- hydroxytryptophan then into serotonin (5-hydroxytryptamine), if all of the co-factors are present.atural Serotonin is involved in the regulation of several processes within the brain, including, depression, mood, emotions, aggression, sleep, appetite, anxiety, memory and perceptions. Serotonin regulates these processes through pathways that innervate (connect to) different brain regions.
More than 90% of the body's serotonin lies in the gut, as well as about 50% of the body's dopamine, which is currently being studied to further our understanding of its utility in the brain. The enteric nervous system has the capacity to alter its response depending on such factors as bulk and nutrient composition.