Search results
Results From The WOW.Com Content Network
A simplified image showing peristalsis. In the esophagus, two types of peristalsis occur: First, there is a primary peristaltic wave, which occurs when the bolus enters the esophagus during swallowing. The primary peristaltic wave forces the bolus down the esophagus and into the stomach in a wave lasting about 8–9 seconds.
The first two in the sequence are by far the most common; 'tertiary' appears occasionally, and higher numbers are rare except in specialized contexts ('quaternary period'). The Greek series proto- , deutero- , trito- , ... is only found in prefixes, generally scholarly and technical coinages, e.g. protagonist, deuteragonist, tritagonist ...
Diffuse esophageal spasm (DES) is a motility disorder characterized by recurrent episodes of chest pain or dysphagia as well as nonpropulsive (tertiary) contractions on radiographs. [5] Nutcracker esophagus is characterized by high-amplitude peristaltic contractions that are frequently prolonged and cause dysphagia and chest pain. [6]
The nervous system, and endocrine system collaborate in the digestive system to control gastric secretions, and motility associated with the movement of food throughout the gastrointestinal tract, including peristalsis, and segmentation contractions.
It is the part of the throat immediately behind the nasal cavity at the back of the mouth and above the esophagus and larynx. The pharynx is made up of three parts. The lower two parts—the oropharynx and the laryngopharynx are involved in the digestive system. The laryngopharynx connects to the esophagus and it serves as a passageway for both ...
Three sectors according to Fourastié Clark's sector model This figure illustrates the percentages of a country's economy made up by different sector. The figure illustrates that countries with higher levels of socio-economic development tend to have less of their economy made up of primary and secondary sectors and more emphasis in tertiary sectors.
The classification of primary, secondary, and tertiary sources can be different in various disciplines and may depend on the context in which the source is used. The examples and definitions given in these guidelines are provided as an aid for more informed discussion of these classification issues when they come up.
An alpha-helix with hydrogen bonds (yellow dots) The α-helix is the most abundant type of secondary structure in proteins. The α-helix has 3.6 amino acids per turn with an H-bond formed between every fourth residue; the average length is 10 amino acids (3 turns) or 10 Å but varies from 5 to 40 (1.5 to 11 turns).