Introduction

The gastrointestinal tract or digestive tract includes a series of hollow organs beginning with the mouth, leading to the esophagus and extends through the stomach, small and large intestine to the anus. All these organs have uniformity in the structural wall, which include four layers from outer surface to
inward: (1) the serosa, (2) a longitudinal smooth muscle layer, (3) a circular smooth muscle layer, (4) the submucosa, and (5) the mucosa.Food ingested is digested in the stomach and small intestine, while the digested food is absorbed in the small intestine and solid wastes are expelled as faeces via the anus.  

The GI tract is divided into two main sections: the upper GI tract and the lower GI tract. The upper GI tract refers to the mouth, esophagus, stomach duodenum, jejunum, and ileum, while the lower GI tract runs from the small intestine to the large intestine (colon) to the anus. In addition to these hollow organs, there are various accessory organs that assist the tract by secreting enzymes to help break down food into its component nutrients. These include the salivary glands, liver, pancreas and gall bladder which play a vital role in food digestion. 

The digestive process starts in your mouth when you chew. Saliva,in the oral cavity, helps moistens food so it moves more easily through your esophagus into your stomach. The esophagus propels ingested food from the pharynx into the stomach via a wave of highly coordinated esophageal peristalsis.  Glands in your stomach lining make stomach acid and enzymes that break down food. Muscles of your stomach mix the food with these digestive juices to produce a semifluid pulp of partially digested food known as chyme.

Bile and pancreatic juice - empty into the first portion of small intestine - which aid to complete the breakdown of proteins, carbohydrates, and fats.  Your small intestine also absorbs water with other nutrients. All significant absorption of nutrients occurs in the small intestine. In large intestine, more water moves from your GI tract into your bloodstream while the accumulation of unabsorbed material forms faeces expelled through the body via anus. The bacteria are responsible for the formation of intestinal gas.

After the end of the course, students will be able to learn about

1. Overview of gastrointestinal tract anatomy and physiology

2. Motor and Neural control of GIT motility

3. Motor and Neural control of GIT secretions

4. Digestion and absorption in GIT

5. Underlying physiology of common gastrointestinal disorders

Further Reading:

 1. TEXTBOOK OF MEDICAL PHYSIOLOGY, GUYTON,A.C, 13TH Edition 

  2. HUMAN ANATOMY & PHYSIOLOGY (Marieb, Human Anatomy & Physiology) , 10th Edition

  3. REVIEW OF MEDICAL PHYSIOLOGY ,GANONG,W.F, 25th Edition

Evaluation Criteria

1. Oral Quiz/Assignment  (Class)

2. Class tests

3. Written Exam

4. Oral/Viva/Practical exam