The structure of pharyngeal isthmus is

The structure of pharyngeal isthmus is tonsil, palatoglossal arch, palatopharyngeal arch, parapharyngeal cord and pharyngeal wall without obvious submucosal tissue layer.

The pharyngeal isthmus is a narrow place surrounded by the palatal lobe, the free edge of the palatal sail, the palatal and lingual arches on both sides and the base of the tongue, which is called the pharyngeal isthmus. It is the opening of the mouth and the boundary between the mouth and throat.

Angina is an acute inflammation that occurs in the pharyngeal isthmus, and it is a special type of pharyngitis. Pharyngeal isthmus refers to the annular structure on the vertical plane of pharynx. The upper part is the free edge of uvula and bilateral soft palate, the lower part is the root of tongue, and the left and right surfaces are palatoglossal arch and palatopharyngeal arch. These four structures are isomorphic to form an annular narrow part called pharyngeal isthmus.

Angina pectoris can be caused by bacteria, viruses and other germs, manifested as sore throat, dry throat, foreign body sensation, herpes, ulcers and so on. , similar to acute tonsillitis. Streptococcus angina pectoris is an unclassified streptococcus, which is considered as a synonym for Streptococcus miller. There are β hemolytic and non β hemolytic strains.

Non-β hemolysis has the same Lancefield antigen and belongs to green streptococcus. There are three kinds of streptococcus, namely, Streptococcus Miller, Streptococcus intermedia and Streptococcus Constellation. Streptococcus viridis is generally a conditional pathogen, and specimens in non-sterile areas are generally not identified. Streptococcus angina was isolated from cerebrospinal fluid, especially the first smear staining of cerebrospinal fluid. Under the microscope, nearly all fields of vision and 100% gram-positive cocci were found, which were rare.

After routine tooth extraction, infection of tooth extraction wound is rare. Most of them are chronic infections caused by foreign bodies such as dental chips, bone chips and tartar and residual granulation tissue. Acute infection after tooth extraction mainly occurs after mandibular wisdom teeth are extracted, especially after tooth extraction and improper treatment during acute inflammation.