Intravenous anesthetic is delivered either by bolus doses or an infusion pump. It can be given both as a bolus as well as constant infusion. The rapid acting insulin is used as a bolus dosage. No reduction in the bolus dose is needed. A bolus of the compound is injected into the venous system. This is especially true with bolus dosing (Canadian term). Contrast is injected and the scan performed using a bolus tracking method. These simplify the tasks involved in delivering an insulin bolus. Among them, for research purposes, by administering a bolus injection of the neuropeptide cholecystokinin-tetrapeptide (CCK-4). Saliva helps to hold together the formed bolus which is swallowed after chewing. After food is chewed into a bolus, it is swallowed and moved through the esophagus. However, propagation of the food bolus is significantly slower than in the pharynx. The digestive functions of saliva include moistening food and helping to create a food bolus. Solids clump together to form the cud or bolus. The solids lump together to form a bolus (or cud), and is regurgitated.