What controls the release of chyme from the stomach to the highlighted structure?

Gastrointestinal phase is one of the gastric phase which controls the release of chyme from the stomach to the highlighted structure.
Chyme is the semi liquid mass of partially digested food and gastric juice, it is acidic in nature. There are three gastric control: cephalic phase, gastric phase and gastrointestinal phase.

Neurotransmitters are messengers responsible for communication between neurons. they are released from synaptic vesicles and are received by receptors.  the communication is referred to as neurotransmission. the following statement is true about neurotransmitters: a. they're stored in synaptic vesicles in the axon.