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.
At either end of the esophagus are ring-shaped muscles (the upper and lower esophageal sphincters), which open and close. The esophageal sphincters normally prevent the contents of the stomach from flowing back into the esophagus or throat. How the Esophagus Works As a person swallows, food moves from the mouth to the throat, also called the pharynx (1).