The digestive system is the system that regulates the digestion of food by the breaking down of food into smaller bits and pieces, so the body easily absorbs its nutrients for regular healthy workings of the body. This system is made up of the gastrointestinal tract, liver, pancreas, gallbladder, salivary glands, and the tongue.
The process of digestion has 3 phases:
- Cephalic phase: This phase is initiated by the cerebral cortex and the appetite center of the amygdala and hypothalamus. This neurological initiation causes gastric secretion in response to the smell and sight of food. This phase includes a chewing and chemical breakdown in the mouth by digestive enzymes.
- Gastric phase: Begins when food gets to the stomach, then more hydrochloric acid is produced in order to lower the PH so further food break down is possible.
- Intestinal phase: in this phase, the remnant of food left after the breakdown in the stomach is called chyme. Chyme is further broken down in the first part of the small intestine called the duodenum. Any remnants left after this phase is passed throughout the rest of the small intestine, down to the large intestine, then to the rectum, and finally to the anus and push out as a waste product.
The gastrointestinal tract is made up of the:
- Esophagus: is 25cm long tube in the human body that runs behind the trachea(windpipe), it passes through the diaphragm. It expands into the upper part of the stomach( there is a muscle separating the esophagus from the stomach called the lower esophageal sphincter). The lower esophageal sphincter prevents the backflow of food or acid from the stomach into the esophagus. During swallowing, the epiglottis moves backward to prevent food from entering the larynx(voice box) into the lungs.
- Stomach: It is a muscular organ located on the left side of the upper abdominal region. It is divided into four regions, as follows: cardiac – fundus – body – pylorus. (note: antrum is the widest part of the pylorus)
- Small intestine: Duodenum- Jejunum – ileum.
- Large intestine: cecum – ascending colon – transverse colon – descending colon – sigmoid colon.
Symptoms of Gastrointestinal Diseases
The signs and symptoms of gastrointestinal diseases occur when one of the organs of the digestive system has a structural or functional problem either due to unknown causes, infectious, autoimmune, or dysgenesis of that organ.
- Diarrhea: a loose, watery stool with or without blood.
- Constipation: infrequent bowel movements and hard to pass stool
- Vomiting: forcefully expelling the content of the stomach through the mouth.
- Nausea: is an urge to vomit
- Gastrointestinal bleeding: the release of blood from broken vessels in the GI tract.
- Bloating: The buildup of gas in the stomach and intestines.
- Flatulence: The passage of that buildup of gas through the anus It occurs in normal healthy people when they eat certain foods, drinks, etc. but too much of flatulence can be a symptom of some serious abdominal problems.
- Heartburn: Burning sensation in the chest region that can radiate to the neck
- Difficulty swallowing: Difficulty passing food smoothly from the esophagus to the stomach.
- Weight gain or loss: An increase in body mass or a decrease in body mass
- Loss of appetite: no desire to eat
- Indigestion: a feeling of fullness or upper abdominal discomfort.
- Jaundice: the yellowish color of the eyes and skin caused by excess bilirubin.
- Fatty stool: floating stool.
- Ascites: abdominal swelling due to excess fluid accumulation.