The main difference between the abdomen and stomach is that the abdomen refers to the entire region between the chest and pelvis, while the stomach is an organ located in the upper abdomen. The abdomen contains many organs like the stomach, liver, pancreas and intestines, and is involved in various bodily functions. The stomach is specifically responsible for digesting food and breaking it down chemically. Pain in the abdomen can arise from different organs, while stomach pain refers explicitly to discomfort in the stomach organ.
Differences between the abdomen and stomach
| Parameter | Abdomen | Stomach |
| Meaning | The part of the body between the chest and pelvis that contains many organs involved in digestion, breathing, posture, balance | A J-shaped muscular organ that stores and chemically breaks down food |
| Location | Between the chest and pelvis, from below the diaphragm to above the pelvis | In the upper left part of the abdomen |
| Major Function | Breathing, posture, balance, and housing digestive organs | Mechanical and chemical breakdown of food |
| Layers | 9 layers including skin, muscles, fascia, adipose tissue, peritoneum | 3 muscular layers – oblique, circular, longitudinal |
| Size | Much larger region than the stomach | Can expand up to 4 liters when full |
| Organs Contained | Stomach, liver, pancreas, gallbladder, intestines, spleen, kidneys | None, contains only layers of stomach tissue |
| Protective Lining | None specific to abdomen | Mucus layer to protect against gastric acid |
| Contractions | None | Peristaltic motions churn and mix food |
| Conditions Affecting It | GERD, pancreatitis, infections, hernias, kidney stones, menstrual cramps | Gastritis, stomach ulcers, cancers |
| Medical Tests | X-rays, CT scans, MRI | Endoscopy, biopsy |
| Surgeries Done on It | Hernia repair, appendix removal | Gastrectomy for ulcers or cancer |
| Pain Origin | Can be from any abdominal organ | Specifically from stomach disorders |
| Injuries | Vulnerable to blunt trauma | Can be ruptured or bruised |
| Microbiology | Usually sterile | Contains acids, enzymes, microbiome |
| pH | Neutral | Extremely acidic pH of 1.5-3.5 |
| Food Exit | No direct exit | Via pyloric sphincter into intestine |
The abdomen plays a crucial role in several bodily functions. The abdominal muscles are engaged when breathing, allowing the diaphragm to move up and down. Having strong abdominal muscles enhances breathing capacity. The abdomen is also critical for good posture. The abdominal muscles wrap around the torso and support the lower back. Weak abdominals can cause slouching.
For digestion, the abdomen houses organs like the stomach, liver, pancreas and intestines. Food passes through the esophagus into the stomach located in the upper abdomen. The stomach releases acids and enzymes to break down food partially before passing it to the small intestine. The pancreas and liver located in the abdomen also produce chemicals to help digestion.
Various conditions can affect the abdomen. Gastroesophageal reflux disease (GERD) causes acid from the stomach to leak back into the esophagus leading to heartburn. Inflammation of the pancreas (pancreatitis) causes severe abdominal pain. Infections, hernias, kidney stones or menstrual cramps can all manifest as pain or discomfort in the abdominal region.
The stomach plays a vital role in the digestive process. After chewing, food passes down the esophagus and reaches the stomach located in the upper left part of the abdomen. The stomach has an extremely acidic environment, with a pH between 1.5-3.5. This acid kills bacteria and begins breaking down food.
The stomach walls contract in rhythmic motions called peristalsis. This churns and mixes the food with gastric acids and enzymes like pepsin and lipase. These break down proteins and fats. The semi-liquid food mixture after 2-6 hours in the stomach is called chyme.
The stomach absorbs some water, alcohol and medications. It has an inner mucosal lining that secretes mucus to protect itself from the high acidity. Ulcers form when this lining is damaged by H. Pylori bacteria or anti-inflammatory drugs. Gastritis refers to irritation and inflammation of the stomach lining. Stomach cancer begins when cells in the stomach lining start dividing uncontrollably.
Key differences between the abdomen and stomach
- The abdomen is the entire region between chest and pelvis containing many organs, while the stomach is one specific digestive organ in the abdomen.
- The abdomen facilitates breathing, posture and balance along with digestion. The stomach solely handles initial food breakdown.
- Abdominal pain can originate from various organs, while stomach pain refers specifically to the stomach organ.