In our body, all organs are important, except, perhaps, for 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 is almost always reduced to surgery to remove the inflamed process. But the topic of this article is the small and large intestine.
This plexus, called the common word intestines, is an important organ of the digestive system. But what is its role if a 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 length of the intestine. About how such an extended channel looks and consider in the framework of this topic.
Useful channel
The intestine is a rather long hollow tube that fills with itself, almost the entire abdominal cavity. In addition, it is one of the largest organs in the body of an adult. The digestion process started 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. That's interesting, but what is the total length of the human small and large intestine? But more on that later.
In addition, villi contribute to the normal mobility of muscle fibers, which ensures the passage of food through the intestinal canal. But this is not all - the role of this valuable organ is to maintain the effectiveness of the immune system. Useful microorganisms settle on the channel, protecting the internal cavity from the encroachment of pathogenic guests.
Perhaps someone is interested in what is the length of this useful and almost indispensable channel? If the entire tube is fully spread, then the total length of the small and large intestine will be 4-8 meters. However, this characteristic should not worry, it is much more important to protect the body from chemical or mechanical effects.
Intestines are fed through the arteries through which oxygen is delivered. Three large aortas located in the upper, lower region and celiac trunk participate in the blood circulation of the intestine . What does this channel consist of? About it further.
The main intestines
The intestine consists of two main departments:
Each of them, in turn, is divided into several components: the duodenum, skinny and ileum belong to the small intestine, and the blind, colon, sigmoid, direct - to the thick. The thick and thin channel differ from each other not only in their structure, but also in the functions performed. This will be discussed in more detail later. In the meantime, imagine the departments of the small and large intestines of a person separately.
Small intestine
In Latin it sounds like intestinum tenue. This channel originates directly from the sphincter (pylorus) of the stomach, connected to the duodenum. And the thin ileal part ends. Moreover, it is separated from the large intestine by the ileocecal valve, which is also called the Bauginium damper. Blood supply is carried out by the superior mesenteric artery and its branches. Venous fluid, collecting in small vessels, is sent to the liver through the portal vein.
Of the entire length of the colon and small intestine, the length of the latter is 2-4.5 meters. Its internal cavity is represented by several layers:
- mucous membranes;
- external muscle;
- internal muscle;
- submucous;
- follicular plaque.
Moreover, the mucous membrane, in turn, also consists of the epithelial layer, intestinal crypt and muscle layer. Thus, it is seen that the small intestine is quite multilayered.
The duodenum (duodenum)
It connects the stomach, after which it passes into the skinny section. In its shape, this part is similar to a horseshoe that bends 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 departments of the small and large intestine, this part is of great value. Its beginning is covered by 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 adjusting the amount of incoming substances.
Since the duodenum is located immediately after the stomach with its acidic environment, it is alkaline in its cavity. If we compare with other parts of the small intestine, then the mucous membrane is most resistant to the effects of stomach acid, pancreatic enzymes and bile of the liver.
However, if acid from the stomach often enters the duodenal cavity, an inflammatory process called a duodenitis or an ulcer begins. For this reason, you should take care of your stomach, small intestine and large intestine from a young age, since all this is 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 with villi. Actually, thanks to them, the absorption of micronutrients from food into the lymphatic and circulatory network occurs. But besides this, there are other necessary substances and intestinal juice.
The longitudinal and transverse smooth muscle structure of the walls of the intestine contribute to the mixing and advancement of the contents towards the large intestine.
Ileum
This is the final section of the small intestine, which connects to the cecum through the Bauginium damper. The wall here is thicker than that of the lean part of the intestine. The diameter is also quite large. There is one distinctive feature - the presence of Peyer's plaques, which are an accumulation of lymphoid tissue.
Colon
This department is called intestinum crassum. In addition to the small intestine, the colon also plays an equally important role. It closes the digestive tract, and all the remains of the consumed products are collected here. And if in its thin part the process of digestion continues, and it is here that most of the micronutrients are absorbed, then in the large intestine it all ends. In this part, feces are formed.
And since moisture is mainly absorbed here, the mucous membrane is devoid of villi as unnecessary. The muscular structure is more pronounced. As noted above, the thick channel also consists of several sections, which we now consider.
Blind department
Interestingly, both the small and large intestines consist of three sections. The thick digestive canal begins with the blind zone, where the contents of the small intestine enter. And this is where the familiar appendix 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.
Column
This part is also divided into several departments:
- Ascending - originates from the cecum.
- Lateral - takes its place between the ascending and descending parts.
- Descending - follows after the transverse part.
- Sigmoid - closes the colon.
It is very difficult to isolate any more important part of the small and large intestine (with the possible exception of duodenum), since this is a single system without which the body cannot function.
In this section of the digestive tract, there is an intensive absorption of moisture and intestinal juices, more than 10 liters of fluid are formed only in a 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
Completes the intestines. The department begins with the ampullar part, after which the canal gradually narrows, passes into the anal tube and ends with the anus. At the same time, two sphincters are located around it - external and internal. They serve to hold feces between bowel movements.
In order for the process of removing feces to proceed normally and without delay, a large amount of mucus is secreted for this. What is characteristic, bowel movement itself is a rather complicated procedure, where most of the links of the nervous regulation take part.
Functional purpose
Whatever the length of the colon and small intestine, the functionality of the entire digestive tract does not depend on its length. The main task that lies 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 finer 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 the absorption of nutrients occurs. And due to the fact that the sizes of these micropores are very small, this closes the path for pathogens. They can only be in the cavity of the intestinal canal.
Other functions of the small intestine
The small intestine performs other functions:
- Motor - the entire cavity of the channel is represented by ring muscles, during the contraction of which food is promoted.
- Endocrine - responsible for this are special cells that synthesize a certain type of hormone, due to which the intestinal apparatus is ensured. Hormones can also affect other systems of the body, whether it is 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 much more.
- Secretory - the production of intestinal juice, which contains various components for processing and absorption of trace elements extracted from food.
In addition, all together (the colon, rectum, small intestine and all its other parts) provide protective function due to lymphocytes. They can be located singly, or form clusters in the region of Peyer's plaques. As a result, immunity is strengthened, and pathogenic microorganisms that have fallen are neutralized.
Colon responsibilities
As for the large intestine, it also responsibly fulfills its equally important obligations. And this concerns not just one department, but the entire channel. This allows the whole body to function normally. And for this, the functions of the colon are reduced to the following duties:
- Digestion - the processing of residues of consumed products occurs with the release of the last moisture and nutrients from them.
- Absorption - the blind section is responsible for this: beneficial substances and water are subsequently distributed throughout the body through the lymphatic and circulatory networks.
- Further advancement of food - the contents of the large intestine move at a much lower rate relative to other departments. Peristalsis begins only after the next portion of food enters the stomach. This ensures the continuous operation of the digestive tract by strengthening or weakening muscle contractions.
- The removal of toxins - through the anus, the body is freed from everything unnecessary.
As you can see, the thick channel also has an important role. The appearance of the disease affects not only the organ itself, but also negatively affects the digestion process in the small and large intestine.
Other systems are at risk. 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.