In swallowing, one portion is volunatary and one part is involuntary. â¢ Buccal phase o Voluntary contraction of the tongue o Step 1 in figure â¢ Pharyngeal-esophageal phase o Involuntary o Control center in the medulla and lower pon o Step 2-5 in figure.
Considerations. Serotonin is a mood regulator that occurs naturally in the body. When serotonin levels are chemically altered, as they are with the use of diet supplements such as Phentermine, a chemical imbalance occurs that may lead to feelings of anxiety or depression.
Antidepressant drugs do their work by either increasing the production of neurotransmitters or by breaking them down. There are three major neurotransmitters that are involved in depression. These are called dopamine, norepinephrine, and serotonin. Serotonin is sometimes called 5-HT. When the levels of one or more of these neurotransmitters dip or become unbalanced, depression or other conditions may result. The newest class of antidepressants is called selective serotonin and norepinephrine reuptake inhibitors (SNRI's). The drugs from this class used for depression are Effexor XR (venlafaxine), Cymbalta (duloxetine), and Pristiq (desvenlafaxine). SNRI's are capable of acting on both norepinephrine and serotonin.