How do the small and large intestines interact with each other ? What are the features of the presented parts of the digestive tract? What role does the small intestine play in the absorption of nutrients? We will try to answer these and other questions in the material presented.
Human Small Intestine
There are such departments of the small intestine:
- The duodenum connects with the perverse zone of the stomach. This initial part of the small intestine forms a horseshoe loop around the pancreas. The duodenum is located almost completely in the retroperitoneal cavity. Only its small process, an ampule, goes beyond the boundaries of the indicated space.
- The jejunum forms the upper part of the small intestine. Presented in the form of seven loops that lie on the left side of the peritoneum.
- The ileum is located in the lower right abdominal region. Its end in the form of loops goes into the zone of the small pelvis. The ileum connects to the rectum and is in close proximity to the bladder, uterus (in women).
Physical parameters
The above sections of the small intestine in different areas have an uneven diameter. In the distal zone, the indicator is 2-3 cm, in the proximal - 4-6. The thickness of the walls of the small intestine is 2-3 mm, and in the case of tissue contraction reaches 4-5. The length of the small intestine as a whole can be 5-6 meters. At the same time, its weight in an adult is close to 650 g.
Small intestine: departments, functions
The most important digestion processes occur precisely in the small intestine. The mucous membrane of local tissues produces a huge amount of active enzymes. They process hummus - a food slurry created by gastric juices. Here, useful elements are absorbed into the lymphatic and blood capillaries, which ensure their transportation to the tissues of organs and systems. Consider what functions the departments of the small intestine perform:
- The duodenum - hydrolysis of proteins, carbohydrates, fats. It provides the active production of digestive enzymes. It processes undigested food particles of bile, transporting the contents of the stomach.
- The jejunum is a motor, absorbing, hormonal function, hydrolysis of polymers.
- Iliac - transport-motor function. Provides absorption of substances that are formed as a result of hydrolysis. Recycle bile acids.
The ability of small intestinal cells to produce hormones
The production of hormones is a special function of local tissues. The departments of the small intestine are not only part of the digestive tract, but also part of the endocrine system. It produces a wide list of hormones that regulate the transport-motor and digestive activity of the intestine.
The following set of endocrine cells is concentrated in the small intestine:
- I-cells - produce cholecystokinin;
- D cells - somatostatin;
- M cells - motilin;
- G-cells - gastrin;
- K-cells - insulinotropic glucose-dependent polypeptide;
- S-cells are secretin.
Most hormone producing cells are located in the jejunum and duodenum. Their insignificant part is in the iliac.
How does digestion occur in the small intestine?
Digestion in the small intestine is as follows. The slurry pre-treated with saliva and gastric juice coming from the stomach has an acid reaction. In the small intestine, the present mass is alkaline. Thus, optimal conditions are created for the processing of nutrients by enzymes. The breakdown of the protein components of the food slurry occurs under the influence of the following elements of intestinal juices:
- Enzymes enterokinase, kinazogen, trypsin process simple proteins.
- Erepsin breaks down peptides into amino acids.
- Nuclease divides into trace elements complex molecules of protein origin, known as nucleoproteins.
- The enzymes maltase, phosphatase, amylase and lactase break down carbohydrates.
- Lipase processes fats.
After the synthesis of nutrients from food gruel using processing enzymes, carbohydrate and protein components are absorbed by the villi of the small intestine. Next, trace elements enter through the venous capillaries in the liver tissue. In turn, fats are sent to the lymphatic system.
Small bowel disease
The most common ailments that affect the parts of the small intestine are diarrhea and stool retention in the pathways. Defecation disorders are often accompanied by the development of pain syndromes in the peritoneum. Quite often, with poisoning and disorders of the small intestine, abundant gas formation is observed. In this case, the pain is short, moderate and is not a major factor in discomfort.
A common symptom of the development of malfunctions of the small intestine is rumbling in the peritoneum, a sensation of atypical movement in the abdomen. Most often, such manifestations are the result of excessive gas formation as a result of the consumption of legumes, cabbage, potatoes, rye bread. These symptoms may intensify significantly at night.
Failures in the production of enzymes and the breakdown of food slurry into trace elements lead to more serious consequences. If the assimilation of food, due to the absorption of substances into the blood and lymph vessels, does not occur properly, this can lead to weight loss, weakening of bone and muscle tissue. The consequences of digestive disorders are often hair loss, dry skin, the appearance of puffiness in the limbs.
There are several basic conditions that lead to the development of pathologies in the small intestine:
- Malabsorption is a violation of the absorption of nutrients.
- Maldigestia - low digestion activity.
If we talk about insufficient quality processing of food gruel, such phenomena occur against the background of a low content of enzymes in intestinal juices. Low fermentation can be both acquired and genetic. Usually, the pathologies of this plan are the result of chronic inflammation, endocrine diseases, surgical interventions.
Diagnostics
To diagnose the development of diseases of the small intestine, specialists resort to such research methods:
- capsule examination;
- Ultrasound
- colonoscopy;
- endoscopy;
- fibroscopy;
- radiography.
As for analyzes, standard procedures are provided here. The patient gives a sample of feces, blood is taken. Feces are examined for the presence of helminths. When studying blood, the speed of movement of red blood cells is taken into account. Additionally, diagnostics are performed, which allows you to evaluate the work of the liver and thyroid gland.
Treatment
Therapy aimed at restoring the functions of the small intestine, involves, first of all, the elimination of the underlying disease. With a lack of enzymes in intestinal juices take preparations containing their synthetic substitutes. In case of weight loss, funds for parenteral nutrition of tissues are prescribed. The latter contains emulsions of fats, amino acids, protein hydrolysates, and concentrated glucose.
If problems are caused by intestinal dysbiosis, antibiotics are prescribed. The latter can provoke a partial or complete destruction of the beneficial flora. For this reason, after conducting therapy, the patient is prescribed to take "Bifikol", "Lactobacterin" or "Colibacterin" - biological preparations, which have a positive effect on the restoration of intestinal biocenosis.
Quite often, patients who suffer from disorders in the functioning of the small intestine are prescribed medications, which cause compaction of feces. These include drugs with a high content of calcium, bismuth. If the formation of liquid stool causes an insufficient adhesion of fatty acids, activated carbon is used to eliminate the problem. All the above negative manifestations require prior medical attention. In order to bring the small intestine back to normal, it is important to abandon self-medication, timely diagnosis and resort to adequate therapy developed by a specialist.
Finally
So we examined what the small intestine, departments, and the structure of the presented part of the digestive tract are like. As you can see, local tissues are directly involved in the processing of food, its splitting into individual trace elements. The small intestine produces enzymes, vitamins, hormones, substances that help to increase the protective functions of the body. At the same time, the occurrence of a deficiency of beneficial bacteria that live on its walls always leads to the development of pathological conditions.