In the following, “mouth, esophagus, stomach, and intestine” describes diseases that are assigned to this category according to ICD-10 (K00-K14, K20-K31, K35-K38, K40-K46, K50-K52, K55-K64, K65-K67, K90-K93). The ICD-10 is used for the International Statistical Classification of Diseases and Related Health Problems and is recognized worldwide.
Mouth, esophagus, stomach, and intestines
The mouth, esophagus, stomach, and intestines are part of the human digestive system. They are used for the absorption, gradual as well as enzymatic splitting (reduction) and transmission of food or food components so that the body can absorb (assimilate) and utilize them. In this process, high-molecular compounds (carbohydrates, fats, proteins) are converted into low-molecular compounds (mono- and disaccharides/single and double sugars, fatty acids, amino acids). Non-utilizable food components are excreted unchanged. The human digestive system includes (from oral to aboral/away from the mouth):
Upper digestive tract
- Oral cavity (cavum oris)
- Pharynx (throat)
- Esophagus (esophagus)
- Stomach (Gaster)
Lower digestive tract
- Small intestine (intestinum tenue; total length: 5-6 meters).
- Adjoining glands – pancreas (pancreas), liver, gallbladder (vesica biliaris) (see below the topic of the same name).
- Large intestine (intestinum crassum; total length: 1.5 meters).
- Caecum – including appendix vermiformis (appendix).
- Colon (colon) – ascending colon (ascending colon), C. transversum (transverse colon), C. descendes (descending colon), C. sigmoideum (sigmoid).
- Rectum (rectum, rectum; length: 12-15 centimeters).
- upper area of the rectum is called the ampulla (ampulla recti); leads over into
- Anal canal (Canalis analis; length 3-4 centimeters) – lower section of the rectum that leads outward through the anus
- upper area of the rectum is called the ampulla (ampulla recti); leads over into
Anatomy
Oral cavityThe oral cavity is bounded by the lips, cheeks, floor of the mouth as well as the palate. It is lined with a mucous membrane (mucosa) that contains many small glands, the salivary glands. 1-1.5 liters of saliva are produced per day. The mucosa of the mouth is colonized by a variety of microorganisms. They form the oral flora. Esophagus (food pipe)The esophagus is a tubular hollow organ and consists of ring-shaped muscles. In an adult, its length is 25-28 cm. It connects the pharynx (throat) to the stomach. StomachThe stomach is a tubular/sacral hollow organ. It is classified as follows:
- Gastric orifice (cardia ventriculi or pars cardiaca, also known as cardia in German) – entrance to the stomach; entrance area of the stomach.
- Fundus (Fundus ventriculi; “bottom of the stomach”) – curved stomach part in the form of a dome.
- Corpus (corpus ventriculi) – centrally located body of the stomach, which is the main part of the stomach.
- Terminal part of the stomach (pars pylorica ventriculi).
- Antrum pyloricum – initial portion of the pars pylorica ventriculi (gastric outlet).
- Gastric portal (pylorus) – sphincter that demarcates the acidic environment of the stomach from the duodenum (duodenal).
The inner wall of the stomach is lined by the gastric mucosa (gastric mucosa). The mucosa is highly folded and interspersed with glandular cells, the gastric glands. A distinction is made between cardia, fundus and pyloric glands. These in turn have different cell types – accessory cells, principal cells, accessory cells – with different functions. Small intestineThe small intestine has a length of up to six meters. To improve absorption (uptake) of nutrients, the mucosa of the small intestine is wrinkled, increasing the surface area of the small intestine. The folds are up to 1 cm high (Kerck ring folds). Characteristic features of the small intestinal mucosa are the small intestinal villi (villi intestinales) – finger-shaped projections – and the tubular depressions (Lieberkühn crypts). Large intestineThe large intestine is approximately 1.5 m long. Unlike the small intestine, the mucosa of the colon does not have villi, but it does have bulges (crescent-shaped folds) that lead to an increase in surface area. The colon is densely colonized by various bacterial strains.They are important for healthy intestinal flora.The lower section of the colon is the rectum (rectum). It is about 20 cm long and is divided into rectum and anal canal. The latter is about three to four cm long. The colon ends with the anus/after.
Physiology
MouthDigestion begins in the mouth. First, food is mechanically broken down by the teeth or chewing and mixed with saliva, producing a pulp that can be swallowed. Saliva production is reflexive. Stimuli are smell, taste and appearance of the food. Saliva contains, among other things, the enzyme ptyalin, an α-amylase, which breaks down the starch (carbohydrate; polysaccharide/multi-sugar) contained in the food to maltose (carbohydrate; disaccharide/di-sugar). The tongue then carries the food pulp into the pharynx (throat) and from there it enters the esophagus (food pipe). EsophagusBy contracting and relaxing the ring-shaped muscles, wave-like movements are created by which the food is transported into the stomach. StomachThe stomach performs both secretory and mechanical functions. Proteins (proteins) are broken down enzymatically in the stomach. The chyme (food pulp) is mixed with gastric juice by peristaltic (wave-like) movements, which emulsifies the fats contained in the food, which is important for further fat digestion. Carbohydrate digestion does not continue in the stomach because the acidic environment deactivates the necessary enzymes. The accessory cells of the gastric mucosa produce hydrochloric acid and the so-called intrinsic factor, which is important for vitamin B12 absorption in the small intestine.The accessory cells permanently produce a mucus rich in hydrogen carbonate, which protects the gastric mucosa from the aggressive gastric acid by performing a buffering function to neutralize the gastric acid. Furthermore, the accessory cells are involved in the breakdown of fats. The primary cells produce a digestive enzyme (pepsinogen). This is activated by hydrochloric acid to pepsin and breaks down proteins of the chyme (food pulp) into smaller peptides. Small intestineFrom the stomach, the chyme passes into the duodenum (small intestine). Stomach acid is neutralized by hydrogen carbonate buffer. Digestive enzymes from the liver, gall bladder and pancreas (pancreas) are added to ensure further breakdown of nutrients. In the small intestine, the absorption (uptake) of the nutrient building blocks into the blood takes place via the villi of the small intestine. Large intestineIn the large intestine, water is removed from the food pulp (thickening). In addition, most of the dietary fiber that could not be broken down by the enzymes in the small intestine is fermented by microorganisms and converted into short-chain fatty acids such as acetate (acetic acid), butyrate (butyric acid), propionic acid and gases. This makes it absorbable and usable by the body. The portion of dietary fiber that is not fermented is excreted unchanged through the rectum (rectal) as feces.
Common diseases of the digestive system
It is estimated that about 70% of all people have intestinal problems. The most common diseases of the mouth, esophagus, stomach, and intestines include:
- Abdominal pain (abdominal pain).
- Appendicitis (appendicitis)
- Inflammatory bowel disease (CED)
- Ulcerative colitis – disease of the mucosa of the colon or rectum.
- Crohn’s disease – usually progresses in episodes and can affect the entire digestive tract; characteristic is the segmental affection of the intestinal mucosa (intestinal mucosa), that is, several intestinal segments may be affected, which are separated by healthy sections from each other
- Diarrhea (diarrhea)
- Diverticular disease – inflammation of the wall of the diverticulum (protrusion of parts of the wall of the colon / large intestine).
- Dysbiosis – imbalance of the intestinal flora.
- Emesis (vomiting)
- Functional dyspepsia (irritable stomach)
- Gastritis (inflammation of the gastric mucosa)
- Gastroesophageal reflux disease – reflux of acid gastric juice and other gastric contents into the esophagus.
- Gingivitis (inflammation of the gums)
- Hemorrhoids
- Colon carcinoma (cancer of the large intestine) – is one of the most common cancers in Germany; about 50,000 people are newly diagnosed with colon cancer each year
- Nausea (nausea)
- Constipation (constipation)
- Pulpitis (inflammation of the dental nerve)
- Pyrosis (heartburn)
- Sialadenitis (inflammation of the salivary glands)
- Sialolithiasis (salivary gland disease)
- Duodenal ulcer (duodenal ulcer)
- Ulcus ventriculi (gastric ulcer)
- Celiac disease – chronic disease of the mucosa of the small intestine (small intestinal mucosa), which is based on hypersensitivity to the cereal protein gluten.
The main risk factors for diseases of the mouth, esophagus, stomach and intestines
Behavioral causes
- Diet
- Low fiber, high fat (saturated fat and trans fat), high meat consumption, micronutrient deficiency.
- Consumption of stimulants
- Alcohol consumption
- High coffee consumption
- Tobacco consumption
- Physical inactivity
- Psycho-social situation
- Stress
- Overweight
Causes related to disease
- Chronic renal insufficiency (kidney weakness).
- Chronic pancreatitis (inflammation of the pancreas).
- Helicobacter pylori infection
- Liver cirrhosis (liver shrinkage)
- Crohn’s disease – chronic inflammatory bowel disease.
- Nephrolithiasis (kidney stones)
Medication
- Continuous medication – e.g., cortisone, NSAIDs (non-steroidal anti-inflammatory drugs).
- Cytostatic drugs (active substances in oncology (cancer therapy))
X-rays
- Radiatio (radiotherapy)
Please note that the enumeration is only an extract of the possible risk factors. Other causes can be found under the respective disease.
The main diagnostic measures for diseases of the mouth, esophagus, stomach and intestines
- Colorectal cancer screening
- Intestinal flora analysis
- Abdominal sonography (ultrasound examination of the abdominal organs).
- Gastroscopy (gastroscopy)
- Colonoscopy (colonoscopy)
Which doctor will help you?
For diseases of the mouth, esophagus, stomach and intestines, the first point of contact is the family doctor, who is usually a general practitioner or internist. Depending on the disease or severity, a presentation to a specialist, in this case the gastroenterologist, may be required.