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.
The ridge in the upper part of the picture is the high pressure of the upper esophageal sphincter which only opens for a short time to let water pass. Peristalsis is a radially symmetrical contraction and relaxation of muscles that propagates in a wave down a tube, in an anterograde direction.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.