Gastroenteritis is inflammation of the gastrointestinal tract, involving both the stomach and the small intestine and resulting in acute diarrhea. It can be transferred by contact with contaminated food and water. The inflammation is caused most often by an infection from certain viruses or less often by bacteria, their toxins, parasites, or an adverse reaction to something in the diet or medication.
ANATOMY AND PHYSIOLOGY
The GIT is composed of two general parts, the main GIT start from the mouth to esophagus, to Stomach to Small intestine to Large intestine to Rectum.
The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.
The mouth
Anatomy
o Contains the lips, cheeks, palate, tongue, teeth, salivary glands, masticators/facial muscles and bones. o Anteriorly bounded by the lips.
Physiology
o Important for the mechanical digestion of food o The saliva contains SALIVARY AMYLASE or PTYALIN that starts the INITIAL digestion of carbohydrates
The Esophagus
Anatomy
o A hollow muscular tube o Length - 25cm o Located in the mediastinum, anterior to the spine, posterior to the trachea and heart o The upper third contains skeletal muscles, contains the upper esophageal or hypopharyngeal sphincter o The lower third contains smooth muscles and the esophago-gastric/cardiac sphincter is found here
Physiology
o Functions to carry or propel foods from the oropharynx to the stomach
The Small intestine
Anatomy
o Grossly divided into the Duodenum (proximal), Jejunum (middle) and Ileum (distal). o Longest segment, about 2/3 of the total length
Physiology
o The intestinal glands secrete digestive enzymes that finalize the digestion of all foodstuffs.
The Large intestine
Anatomy
o Approximately 5 feet long
Parts:
1. The Cecum – widest diameter, prone to rupture
2. The Appendix
3. The Ascending colon