The Digestive System Of The Human Body

981 WordsOct 12, 20154 Pages
The digestive system is one of the most overlooked systems in the human body. Although most people cannot sense the system at work like they do when they breathe in air or feel their heart beat, it still continues to deliver nutrients throughout the systems. The digestion system is responsible for nourishing the human body with the energy necessary to stay healthy and getting rid of the unnecessary materials (Marieb 1989). The digestive system is composed of the mouth, pharynx, esophagus, stomach, small and large and intestine and is aided by the mouth’s salivary glands, liver, pancreas and gallbladder, which are considered the accessory organs (Tortora & Derrickson 2014). The system begins with ingestion, or the act of eating and drinking. Once the food enters the mouth, the salivary glands begin the increased enzyme production of salivary amylase in order help with the dissolving of the food and breaking down of polysaccharides into sugars (Tortora & Derrickson 2014). After a bolus has been formed, it is contracted by skeletal muscles from the pharynx to the esophagus where peristalsis contractions keep moving the mass downward until it enters the stomach. The stomach begins to prepare the bolus for digestion by a process called propulsion in which the food is churned and mixed with gastric juices until it becomes chyme, or a liquid substance able to pass through the pyloric sphincter (Marieb 1989). In the meantime, chemical digestion begins as well; parietal cells begin
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