SQL Server distinguishes between 3 different types of latches: 1  IO Latches. 2  Buffer Latches (BUF) 3  Non-Buffer Latches (Non-BUF) Letâs have a more detailed look at these 3 different variations. I/O Latches are used by SQL Server when outstanding I/O operations against pages in the Buffer Pool are done â when you read and write from/to your storage subsystem.
The pharyngeal muscles are a group of muscles that act upon the pharynx. Pharyngeal muscles contracts pushing the food into the oesophagus.There are two muscular layers of the pharynx: the outer circular layer and the inner longitudinal layer.The outer circular layer includes: 1  Inferior constrictor muscle.2  Middle constrictor muscle.haryngeal muscles contracts pushing the food into the oesophagus. There are two muscular layers of the pharynx: the outer circular layer and the inner longitudinal layer. The outer circular layer includes: 1  Inferior constrictor muscle. 2  Middle constrictor muscle.
After food is chewed into a bolus, it is swallowed and moved through the esophagus. Smooth muscles contract behind the bolus to prevent it from being squeezed back into the mouth.Then rhythmic, unidirectional waves of contractions work to rapidly force the food into the stomach.eristaltic movement comprises relaxation of circular smooth muscles, then their contraction behind the chewed material to keep it from moving backward, then longitudinal contraction to push it forward. Earthworms use a similar mechanism to drive their locomotion, and some modern machinery imitates this design.