In our body, all organs are important, with the exception, perhaps, of the appendix, it is believed that its absence does not significantly affect human life. Indeed, in our time there are a lot of people with appendicitis, and the treatment of this disease almost always comes down to an operation to remove the inflamed process. But the topic of this article is the small and large intestine.
This plexus, collectively referred to as the gut, is an important organ in the digestive system. But what is its role if the stomach is used for digestion, in which food, under the influence of acid, decomposes into smaller components? The fact is that the process of digestion does not end in the stomach, but continues throughout the entire length of the intestine. About how such an extended channel looks and we will consider within the framework of this topic.
Useful channel
The intestine is a fairly long hollow tube that fillsalmost the entire abdominal cavity. In addition, it is one of the largest organs in the body of an adult. The process of digestion that began in the stomach continues here. This is done due to the villi that line the inner surface of the organ. To do this, they produce certain hormones. As a result, more vitamins, carbohydrates and fats are released from food. I wonder, what is the total length of the small and large intestines of a person? But more on that later.
In addition, the villi contribute to the normal mobility of muscle fibers, which ensures the passage of food through the intestinal canal. But that's not all - the role of this valuable organ is to maintain the effectiveness of the immune system. Beneficial microorganisms settle inside the canal, which stand guard, protecting the internal cavity from the encroachment of pathogenic guests.
Probably someone is wondering what is the length of this useful and almost irreplaceable channel? If the entire tube is fully extended, then the total length of the small and large intestine will be 4-8 meters. However, this characteristic should not worry, it is more important to protect the organ from chemical or mechanical influences.
The intestines are nourished by the arteries, through which oxygen is delivered. Three large aortas located in the upper, lower region and the celiac trunk participate in the blood circulation of the intestine. What is this channel? More on that later.
Main sections of the intestines
The intestine consists of two mainDepartments:
- colon;
- small intestine.
Each of them, in turn, is divided into several components: the duodenum, jejunum and ileum belong to the small intestine, and the blind, colon, sigmoid, rectum - to the thick. Thick and thin channels differ from each other not only in their structure, but also in their functions. This will be discussed in more detail a little later. In the meantime, let's imagine the sections of the human small and large intestines separately.
Small intestine
Latin for intestinum tenue. This channel originates directly from the sphincter (pylorus) of the stomach, connected to the duodenum. And the thin section ends with the iliac part. Moreover, it is separated from the large intestine by the ileocecal valve, which is also called the Bauhinian damper. Blood supply is provided by the superior mesenteric artery and its branches. The venous fluid, collecting in small vessels, is sent to the liver through the portal vein.
Of the entire length of the large and small intestine, the length of the latter is 2-4.5 meters. Its internal cavity is represented by several layers:
- slimy;
- external muscle;
- internal muscle;
- submucosal;
- follicular plaque.
Moreover, the mucous membrane, in turn, also consists of the epithelial layer, the intestinal crypt and the muscle layer. Thus, it can be seen that the small intestine is quite multi-layered.
The duodenum(KDP)
Connects the stomach, after which it passes into the skinny section. In its shape, this part is similar to a horseshoe that goes around the head of the pancreas. Its length is 17-20 cm. At the same time, it is also divided into several zones:
- top;
- downward;
- horizontal;
- ascending.
Of all the parts of the small and large intestine, this part is the most valuable. Its beginning is covered with oblong folds, while larger papillae are located at its end. In fact, this is the end of the duct, through which bile from the liver enters the cavity of the small intestine. In addition, the pancreas also dumps its enzymes here. Thanks to them, the process of splitting fats, proteins and carbohydrates occurs. The sphincter of Oddi is responsible for regulating the amount of incoming substances.
Since the duodenum is located immediately after the stomach with its acidic environment, it is alkaline in its cavity. Compared to other parts of the small intestine, the mucosa is the most resistant to stomach acid, pancreatic enzymes, and liver bile.
However, if acid from the stomach often enters the cavity of the duodenum, an inflammatory process begins, called duodenitis or an ulcer. For this reason, you should take care of your stomach, small intestine, and large intestine from a young age, as they are all interconnected.
Skinny small intestine
The duodenum is followed by the jejunum. The environment in it is neutral or slightly alkaline, the inner surface of the mucous membrane is also covered withvilli. Actually, thanks to them, micronutrients are absorbed from food into the lymphatic and circulatory network. But besides this, there are other necessary substances and intestinal juice.
Longitudinal and transverse smooth muscle structure of the intestinal walls promote mixing and movement of the contents towards the large intestine.
Ileum
This is the final section of the small intestine, which is connected to the cecum by means of the Bauhin's valve. The wall here is thicker than that of the jejunum. The diameter is also quite large. At the same time, there is one distinctive feature - the presence of Peyer's patches, which are an accumulation of lymphoid tissue.
Large intestine
This department is called intestinum crassum. In addition to the small intestine, the large intestine also plays an equally important role. It closes the digestive tract, and all the remnants of consumed products are collected here. And if the process of digestion continues in its thin part, and it is here that most of the micronutrients are absorbed, then everything ends in the large intestine. In this part, feces are formed.
And since moisture is mainly absorbed here, the mucous membrane is devoid of villi as unnecessary. The muscle structure is more pronounced. As noted above, the thick channel also consists of several sections, which we will now consider.
Blind Department
Interestingly, both the small and large intestines are made up of threedepartments. The large alimentary canal begins at the blind spot where the contents of the small intestine enter. And it is here that the familiar process is located - the appendix. Once scientists considered it a useless organ, but over time they changed their point of view. Its important role in the formation and maintenance of immunity has been proven.
Headpiece
This part is also divided into several sections:
- Ascending - originates from the caecum.
- Transverse colon - takes its place between the ascending and descending parts.
- Descending - follows the transverse rim.
- Sigmoid - closes the colon.
It is very difficult to single out any more important part of the small and large intestines (with the exception of the duodenum), since this is a single system without which the body cannot function.
In this section of the digestive tract, moisture and intestinal juices are intensively absorbed, more than 10 liters of liquid are formed per day. A variety of microorganisms live in the cavity of this channel, forming a microbial film that protects the mucous membrane from the attack of pathogenic bacteria and fungi.
Rectum
Completely completes the intestines. The department begins with the ampullar part, after which the canal gradually narrows, passes into the anus and ends with the anus. At the same time, two sphincters are located around it - external and internal. They serve to hold feces between processes.defecation.
In order for the process of removing feces to proceed normally and without delay, a large amount of mucus is secreted by the mucous membrane for this. Tellingly, defecation itself is a rather complex procedure, which involves most of the links of the nervous regulation.
Functional purpose
Whatever the length of the large and small intestine, the functionality of the entire digestive tract does not depend on its length. The main task that falls on the small intestine is precisely the breakdown and absorption of food. Under the influence of enzymes from the pancreas and bile, proteins, fats, carbohydrates break down into smaller components.
At the same time, in this state, they are not yet absorbed by the body - it is necessary to split them into even smaller fragments. As we know, the surface of the small intestine is covered with villi, which have their own microvilli, and microscopic holes are located between them.
It is through them that nutrients are absorbed. And due to the fact that the size of these micropores is very small, it closes access to pathogens. They remain only in the cavity of the intestinal canal.
Other functions of the small intestine
The small intestine also has other functions:
- Motor - the entire cavity of the canal is represented by circular muscles, during the contraction of which food is promoted.
- Endocrine - special cells are responsible for this,synthesizing a certain type of hormones, due to which the work of the intestinal apparatus is ensured. Hormones can also affect other body systems, be it the cardiovascular, circulatory, nervous, or any other. Most of these cells are located in the duodenum, so this part can be considered the most important among other parts of the small intestine. And if work is disrupted here, a person's condition begins to deteriorate, and strongly.
- Secretory - the production of intestinal juice, which contains various components for the processing and absorption of trace elements extracted from food.
In addition, everything together (large, rectum, small intestine and all other parts of it) provide a protective function due to lymphocytes. They can be located singly, or form clusters in the area of \u200b\u200bPeyer's patches. As a result, immunity is strengthened, and pathogenic microorganisms are neutralized.
Responsibilities of the large intestine
As for the large intestine, it also responsibly fulfills its no less important obligations. And this does not apply to any one department, but to the entire channel. This allows the entire body to function normally. And for this, the functions of the colon are reduced to the following duties:
- Digestion - the remnants of consumed products are processed with the release of the last moisture and nutrients from them.
- Absorption - the blind department is responsible for this: useful substances and water are further distributed throughout the bodythrough the lymphatic and circulatory network.
- Further promotion of food - the contents of the large intestine moves at a much lower speed compared to other departments. Peristalsis begins only after the next portion of food enters the stomach. This ensures the continuous work of the digestive tract by strengthening or weakening muscle contractions.
- Removal of toxins - through the anus, the body is freed from all unnecessary.
As you can see, the thick channel also plays an important role. The appearance of the disease affects not only the organ itself, but also negatively affects the process of digestion in the small and large intestines.
The rest of the systems are under threat. Ultimately, the quality of human life is significantly reduced. At the same time, neoplasms of both malignant and benign nature pose the greatest threat to the human body.
