The test may cause momentary gagging because the back of the throat is a sensitive area, but it should not be painful. The sample your doctor collects is taken to a laboratory, where it is put on a plate that allows any bacteria on it to grow. This process is called a culture.
Often these are called transition zones which represent the start and end of a specific region and can be large or small. For example, the transition zone between Sub-Saharan Africa and North Africa is rather large because there is a mixing between the two regions. Regional geographers study this zone as well as the distinct characteristics of Sub-Saharan Africa and North Africa.
The pectinate line is not seen on inspection in clinical practice, but under anesthesia the anal canal descends down, and the pectinate line can be seen on slight retraction of the anal canal skin. The anal canal just below the pectinate line for about 1-2 cm is called the anal pecten or transitional zone.Above this transitional zone, the anal canal is lined with columnar epithelium (which is insensitive to cutting).he pectinate line is the site of transition of the proctodeum below and the postallantoic gut above. It is a scalloped demarcation formed by the anal valves (transverse folds of mucosa) at the inferior-most ends of the anal columns. Anal glands open above the anal valves into the anal sinuses.