Digestion of food begins inoral cavity. This is where the food bolus forms. Food is crushed with the help of teeth and moistened with saliva. Thoroughly chewed food mixed with saliva is better digested and absorbed faster. Saliva consists of 99-99.5% water, organic and inorganic compounds - enzymes and salts - 0.5-1%. The reaction of saliva is slightly alkaline.
When you have dental disease, digestion is disrupted because food that is insufficiently chewed and not prepared for chemical treatment enters the stomach. This is why it is so important to constantly take care of your teeth. After chewing thoroughly the consistency of food becomes more suitable for further digestion. The breakdown of carbohydrates begins in it, and bacteria are partially destroyed.
The reflex act of swallowing is the entry of food intoesophagus.The stimulus for the swallowing reflex is a mechanical effect on the root of the tongue. The center of the swallowing reflex is located in the medulla oblongata.
Contraction of the muscles of the tongue and pharynx promotes the movement of the bolus of food into the esophagus and further into the stomach. When swallowing, the epiglottis closes the entrance to the larynx and trachea, and the soft palate closes the entrance to nasal cavity(see Fig. 108). When talking while eating, pieces of food can get into the larynx. This causes a cough and sometimes shortness of breath.
There are very few glandular cells in the epithelium of the esophagus. They generally provide better advancement (sliding) of the food bolus, but do not secrete enzymes. Food continues to interact with salivary enzymes and entersstomach.
Gastric juice is secreted by small glands of the gastric mucosa.Uan adult person excretes about2 lgastric juice. The intensity of its secretion depends on the composition and consistency of the food.
Alcohol and smoking have bad influence on digestion in the stomach. Alcohol disrupts stomach functions. Nicotine, coming along with saliva, causes inflammation of the mucous membrane of the gland.
pipe U constantly smoking people chronic gastritis is observed. Sometimes damaged under the influence of nicotine soft fabrics, blood vessels, and a stomach ulcer forms.
Intestinal digestion. Suction. INsmall intestinetransformation occurs nutrients into those compounds that are absorbed by the body. The digestion process here consists of 3 stages:cavity digestion(under the influence of digestive juices),parietal(membrane)digestion(on a surface intestinal cells) Andintracellular.
Intestinal digestion begins in the duodenum. Here food is processed by pancreatic juice of the pancreas and baked with bile
One of the main functions of the liver is to participate in the breakdown of fats. By using bile acids bileemulsifiesfats, i.e., transforms them into an emulsion state. Without this, pancreatic juice is not able to break down solid animal fats.
When eating fatty meat, a lot of bile is released, and the cholesterol level in the blood increases. It can accumulate inBiuesmall crystals and promote the formation of stones in the gallbladder and ducts.
After the action of bile (pH), the environment of the food gruel (chyme) becomes slightly alkaline, fats are emulsified, which ensures the unhindered functioning of pancreatic enzymes. But basically, fats are broken down by lipase and the remaining carbohydrates are broken down by amylase.
Further and final digestion occurs in the following sections small intestine Under the influenceintestinal juice.It contains water, organic and inorganic substances, as well as more than 20 enzymes. They finally digest the nutrients.
Thanks to contractions of the walls of the small intestine, food moves back and forth. Thorough mixing of the intestinal contents occurs. It takes the form of a liquid homogeneous mass. At the same time, digestion processes occur on the surface of the mucous membrane of the small intestine. It is gathered into folds. And the folds are covered with tiny fibers up to 1.5 mm long (Fig. 125V. G).INEach villus has capillaries. There is a lot of villi. If only I could unfold all the fibers small intestine, then they would occupy an area several tens of times greater than the surface area of the body. And along this entire surface, nutrients pass through the walls of the capillaries into the blood and lymph. This process is calledsuction.This is how the body receives all the substances it needs.
Thus, the final
Rice. 125.Digestion and absorption of food:
/ upper jaw;2 - language;3 - pharynx;4 - salivary glands;5 - epiglottis;6 - trachea; 7 - esophagus;8 - liver;9 stomach;10- gallbladder; 11 - duodenum;12 - small intestine;13 - pancreas;14 - colon;15 - rectum;A)movement of food along the esophagus;b)section of the gastric mucosa;V)mucous membrane of the small intestine; d) villi of the small intestine
food digestion and absorption nutrients into the blood (proteins and carbohydrates) and lymph (fats).
In the large intestine, water is absorbed and feces are formed. The large intestine is home to many microorganisms that are symbionts (cohabitants) of our body. First of all thiscoli.They protect the human body from harmful microorganisms. In addition, they break down plant fiber, which changes little in the small intestine, synthesize some vitamins and contribute to the normal functioning of the digestive system. You should not use antibiotics thoughtlessly, as this can cause the death of not only harmful, but also beneficial bacteria and lead to dysbacteriosis.
Section of the alimentary canal | Structural features | Allocable parts | Food juice | Basic processes |
Oral cavity | Limited to the cheeks, lips and palate. Includes teeth and tongue | Vestibule and oral cavity | Saliva | 1disinfection; 2- grinding: 3-definition taste; 1 - breakdown of carbohydrates |
Pharynx | Tubular cavity. limited by the epiglottis, tonsils | 1nasopharynx; 2oropharynx; 3- laryngeal Part | Entry of bolus food into the esophagus - swallowing |
|
Penshenol | The muscles are initially striated, in the 2nd and 3rd parts they are smooth | Delivery of food to the stomach |
||
Stomach | Mucous forms folds. 3 layers of muscles | 1- bottom; 2- body: 3- gatekeeper | Zhelu daughter | Split proteins |
Thin kishe"pshk | Yali "she thief of the sinus and ileum | 1- duodenum 12: 2- skinny; 3- ileum | Bile, pancreatic and intestinal | Emulsification of fats, final digestion. absorption of nutrients into the blood and lymph |
Thick intestines | Folds of the mucous membrane; many lymph nodes in the risers; body fat outside | 1- blind (-♦ appendix); 2- colon (ascending, transverse, descending, sigmoid); 3straight | Slime, intestinal | 1suction I.O. salts and vitamins soluble in it; 2synthesis of some vitamins; rectum.Emptying the rectum is a complex reflex act. The center of this reflex is located in sacral region spinal cord. Thus, in the digestive organs, nutrients are crushed and broken down and absorbed into the blood and lymph. They are then distributed to all cells and tissues of the body. Undigested substances are excreted. Intestinal digestion, absorption, cavity digestion, parietal digestion, emulsification, E. coli. 1. What changes occur with food in the oral cavity? 2.What substances affect food in the small intestine? 3.Which organ has villi? What function do they perform? 1.Where is gastric juice secreted and what is its composition? 2.What are the features of digestion in the stomach and small intestine? 3.What is the role of the large intestine in digesting food? 1.In which organ does food digestion end? 2.Name the products of the breakdown of proteins, fats and carbohydrates. 3.Describe the ways food is absorbed. MP. I. Effect of salivary enzymes on starch. Equipment:dry starch, gauze, water, flat dishes, test tube, alcohol lamp or electric stove, iodine. matches, cotton wool. 1.If there is any sticking in the dishes, add a little water, add 1 minute spoon of starch and bring to a boil with constant stirring. 2.Soak a piece of bandage in starch and squeeze it out. 3.Wrap a little cotton wool around the head of the match, moisten it generously with saliva and write a letter or number on a piece of bandage soaked in starch. 4.Then warm this bandage, holding it in your hands for 2-4 minutes. 5.Pour into a small container water solution iodine and place a bandage there. 6.Examine the bandage. Starched areas are painted Blue colour, and the area moistened with saliva does not stain, because under the influence of salivary enzymes, starch is broken down into glucose. II. The influence of gastric juice enzymes on egg white. Equipment:gastric juice, soft-boiled egg. Place the pieces into two test tubes egg white and add canned gastric juice. One test tube is left anddRyesthey will interfere with warm water with a temperature of 38... 39 "C for 20-30 minutes. Compare the test tubes. In which of them do changes occur and why? |
To maintain his life, a person must eat food. Food products contain all the substances necessary for life: water, mineral salts and organic compounds. Proteins, fats and carbohydrates are synthesized by plants from non- organic matter using solar energy. Animals build their bodies from nutrients of plant or animal origin.
Nutrients that enter the body with food are building materials and at the same time a source of energy. During the breakdown and oxidation of proteins, fats and carbohydrates, a different but constant amount of energy is released for each substance, characterizing their energy value.
Digestion
Once in the body, food products undergo mechanical changes - they are crushed, wetted, split into simpler compounds, dissolved in water and absorbed. The set of processes by which nutrients are removed from environment pass into the blood, called digestion.
Play a huge role in the digestion process enzymes- biologically active protein substances that catalyze (accelerate) chemical reactions. During digestion processes, they catalyze reactions of hydrolytic breakdown of nutrients, but do not themselves change.
Main properties of enzymes:
- specificity of action - each enzyme breaks down nutrients only certain group(proteins, fats or carbohydrates) and does not break down others;
- act only in a certain chemical environment - some in alkaline, others in acidic;
- enzymes are most active at body temperature, and at a temperature of 70–100ºС they are destroyed;
- a small amount of enzyme can break down large mass organic matter.
Digestive organs
The alimentary canal is a tube that runs throughout the body. The canal wall consists of three layers: outer, middle and inner.
Outer layer (serosa) is formed by connective tissue that separates the digestive tube from surrounding tissues and organs.
Middle layer(muscular membrane) in upper sections the digestive tube (oral cavity, pharynx, upper part of the esophagus) is striated, and in the lower parts it is smooth muscle tissue. Most often, the muscles are located in two layers - circular and longitudinal. Thanks to the contraction of the muscular membrane, food moves through the digestive canal.
Inner layer(mucous membrane) is lined with epithelium. It contains numerous glands that secrete mucus and digestive juices. In addition to small glands there are large glands(salivary, liver, pancreas) lying outside alimentary canal and communicating with them through their channels. The following sections are distinguished in the digestive canal: oral cavity, pharynx, esophagus, stomach, small and large intestines.
Digestion in the mouth
Oral cavity- initial department digestive tract. From above it is limited by solid and soft palate, from below by the diaphragm of the mouth, and from the front and sides - by the teeth and gums.
Three pairs of ducts open into the oral cavity salivary glands: parotid, sublingual and submandibular. In addition to these, there is a mass of small mucous salivary glands scattered throughout the oral cavity. The secretion of the salivary glands - saliva - moistens food and participates in its chemical changes. Saliva contains only two enzymes - amylase (ptialin) and maltase, which digest carbohydrates. But since food does not remain in the oral cavity for long, the breakdown of carbohydrates does not have time to complete. Saliva also contains mucin (mucus substance) and lysozyme, which has bactericidal properties. The composition and quantity of saliva may vary depending on physical properties food. During the day, a person secretes from 600 to 150 ml of saliva.
In the oral cavity, an adult has 32 teeth, 16 in each jaw. They grab food, bite it off and chew it.
Teeth consist of a special substance dentin, which is a modification bone tissue and having greater strength. The outside of the teeth is covered with enamel. Inside the tooth there is a cavity filled with loose connective tissue containing nerves and blood vessels.
Most of the oral cavity is occupied tongue, which is a muscular organ covered with mucous membrane. It is distinguished by the top, root, body and back, on which taste buds are located. The tongue is the organ of taste and speech. With its help, food is mixed during chewing and pushed through when swallowing.
Food prepared in the oral cavity is swallowed. Swallowing is a complex movement that involves the muscles of the tongue and pharynx. During swallowing, the soft palate rises and blocks the food from entering the nasal cavity. At this time, the epiglottis closes the entrance to the larynx. The food bolus gets into throat - top part digestive canal. It is a tube inner surface which is lined with mucous membrane. Through the pharynx, food enters the esophagus.
Esophagus- a tube about 25 cm long, which is a direct continuation of the pharynx. No food changes occur in the esophagus, since digestive juices are not secreted in it. It serves to carry food into the stomach. The movement of the food bolus through the pharynx and esophagus occurs as a result of contraction of the muscles of these sections.
Digestion in the stomach
Stomach- the most expanded section of the digestive tube with a capacity of up to three liters. The size and shape of the stomach changes depending on the amount of food taken and the degree of contraction of its walls. At the point where the esophagus flows into the stomach and where the stomach passes into the small intestine, there are sphincters (squeezers) that regulate the movement of food.
The mucous membrane of the stomach forms longitudinal folds and contains a large number of glands (up to 30 million). The glands consist of three types cells: main (producing enzymes of gastric juice), parietal (secreting hydrochloric acid) and accessory (secreting mucus).
Contractions of the stomach walls mix food with juice, which facilitates its better digestion. Several enzymes are involved in the digestion of food in the stomach. The main one is pepsin. It breaks down complex proteins into simpler ones, which are further processed in the intestines. Pepsin acts only in acidic environment, which is created by hydrochloric acid in gastric juice. A big role is given hydrochloric acid in the disinfection of stomach contents. Other gastric juice enzymes (chymosin and lipase) are able to digest milk protein and fats. Chymosin curdles milk, so it stays in the stomach longer and undergoes digestion. Lipase, present in small quantities in the stomach, breaks down only the emulsified milk fat. The action of this enzyme in the stomach of an adult is weakly expressed. There are no enzymes that act on carbohydrates in gastric juice. however, a significant portion of the food's starch continues to be digested in the stomach by salivary amylase. The mucus secreted by the glands of the stomach plays important role in protecting the mucous membrane from mechanical and chemical damage, from the digestive action of pepsin. The glands of the stomach secrete juice only during digestion. In this case, the nature of juice secretion depends on chemical composition consumed food. After 3-4 hours of processing in the stomach, the food gruel enters the small intestine in small portions.
Small intestine
Small intestine It is the longest part of the digestive tube, reaching 6–7 meters in an adult. It consists of the duodenum, jejunum and ileum.
The excretory ducts of two large digestive glands - the pancreas and liver - open into the initial section of the small intestine - the duodenum. Here the most intensive digestion of food gruel occurs, which is exposed to the action of three digestive juices: pancreatic, bile and intestinal.
Pancreas located behind the stomach. It distinguishes between the apex, body and tail. The apex of the gland is surrounded in a horseshoe shape by the duodenum, and the tail is adjacent to the spleen.
Gland cells produce pancreatic juice (pancreatic). It contains enzymes that act on proteins, fats and carbohydrates. The enzyme trypsin breaks down proteins into amino acids, but is active only in the presence of the intestinal enzyme enterokinase. Lipase breaks down fats into glycerol and fatty acids. Its activity increases sharply under the influence of bile produced in the liver and entering the duodenum. Under the influence of amylase and maltose in pancreatic juice, most food carbohydrates are broken down into glucose. All pancreatic juice enzymes are active only in an alkaline environment.
In the small intestine, food gruel undergoes not only chemical, but also mechanical processing. Thanks to the pendulum-like movements of the intestine (alternate lengthening and shortening), it mixes with digestive juices and liquefies. Peristaltic movements of the intestines cause contents to move towards the large intestine.
Liver- the largest digestive gland in our body (up to 1.5 kg). It lies under the diaphragm, occupying right hypochondrium. The gallbladder is located on the lower surface of the liver. The liver consists of glandular cells that form lobules. There are layers between the lobules connective tissue, in which nerves, lymphatic and blood vessels and small bile ducts pass.
Bile, produced by the liver, plays a large role in the digestion process. It does not break down nutrients, but prepares fats for digestion and absorption. Under its action, fats break up into small drops suspended in liquid, i.e. turn into an emulsion. In this form they are easier to digest. In addition, bile actively influences absorption processes in the small intestine, enhances intestinal motility and the secretion of pancreatic juice. Despite the fact that bile is produced continuously in the liver, it enters the intestines only when eating. Between periods of digestion, bile is collected in the gallbladder. By portal vein flows into the liver deoxygenated blood from the entire alimentary canal, pancreas and spleen. Toxic substances that enter the blood from the gastrointestinal tract are neutralized here and then excreted in the urine. In this way, the liver carries out its protective (barrier) function. The liver is involved in the synthesis of a number of important substances for the body, such as glycogen, vitamin A, and influences the process of hematopoiesis, the metabolism of proteins, fats, and carbohydrates.
Nutrient Absorption
So that the amino acids formed as a result of the breakdown simple sugars, fatty acids and glycerol have been used by the body, they must be absorbed. These substances are practically not absorbed in the oral cavity and esophagus. Water, glucose and salts are absorbed in the stomach in small quantities; in the large intestines - water and some salts. The main processes of nutrient absorption occur in the small intestine, which is quite well adapted to carry out this function. The mucous membrane of the small intestine plays an active role in the absorption process. It has a large number of villi and microvilli, which increase the absorption surface of the intestine. The walls of the villi contain smooth muscle fibers, and inside them there are blood and lymphatic vessels.
Villi take part in the absorption of nutrients. By contracting, they promote the outflow of blood and lymph, rich in nutrients. When the villi relax, fluid from the intestinal cavity again enters their vessels. The products of the breakdown of proteins and carbohydrates are absorbed directly into the blood, and the bulk of digested fats are absorbed into the lymph.
Colon
Colon has a length of up to 1.5 meters. Its diameter is 2–3 times larger than the thin one. It contains undigested food residues, mainly plant foods, the fiber of which is not destroyed by enzymes of the digestive tract. There is a lot in the large intestine various bacteria, some of which play an important role in the body. Cellulose bacteria break down fiber and thereby improve absorption plant food. There are bacteria that synthesize vitamin K, which is necessary for the normal functioning of the blood coagulation system. Thanks to this, a person does not need to take vitamin K from external environment. In addition to the bacterial breakdown of fiber in the large intestine, absorption occurs large quantities water that enters there along with liquid food and digestive juices ends with the absorption of nutrients and the formation of feces occurs. The latter pass into the rectum, and from there are excreted through anal hole. The opening and closing of the anal sphincter occurs reflexively. This reflex is under the control of the cerebral cortex and can be voluntarily delayed for some time.
The entire process of digestion with animal and mixed food in humans lasts about 1–2 days, of which more than half of the time is spent moving food through the large intestines. Feces accumulate in the rectum, and as a result of irritation of the sensory nerves of its mucous membrane, defecation occurs (emptying the colon).
The digestion process is a series of stages, each of which takes place in a certain part of the digestive tract under the influence of certain digestive juices secreted by the digestive glands and acting on certain nutrients.
Oral cavity- the beginning of the breakdown of carbohydrates under the action of salivary enzymes produced by the salivary glands.
Stomach- breakdown of proteins and fats under the influence of gastric juice, continuation of the breakdown of carbohydrates inside the bolus of food under the influence of saliva.
Small intestine- completion of the breakdown of proteins, polypeptides, fats and carbohydrates under the action of enzymes of pancreatic and intestinal juices and bile. Complex organic substances result biochemical processes turn into low-molecular ones, which, being absorbed into the blood and lymph, become a source of energy and plastic materials for the body.
Nutrition is a complex process through which food is received, digested and absorbed. necessary for the body substances. Over the past ten years, a special science devoted to nutrition—nutritiology—has been actively developing. In this article we will look at the process of digestion in the human body, how long it lasts and how to manage without a gallbladder.
The structure of the digestive system
It is represented by a set of organs that ensure the absorption of nutrients by the body, which are a source of energy for it, necessary for cell renewal and growth.
The digestive system consists of: the mouth, pharynx, small intestine, colon and rectum.
Digestion in the human oral cavity
The process of digestion in the mouth involves grinding food. In this process, vigorous processing of food with saliva occurs, interaction between microorganisms and enzymes. After treatment with saliva, some of the substances dissolve and their taste appears. Physiological process Digestion in the oral cavity consists of the breakdown of starch into sugars by the amylase enzyme contained in saliva.
Let's trace the action of amylase using an example: while chewing bread for a minute, you can feel sweet taste. The breakdown of proteins and fats does not occur in the mouth. On average, the digestion process in the human body takes approximately 15-20 seconds.
Digestive department - stomach
The stomach is the widest part of the digestive tract, has the ability to expand in size, and can accommodate huge amounts of food. As a result of the rhythmic contraction of the muscles of its walls, the process of digestion in the human body begins with thorough mixing of food with gastric juice, which has an acidic environment.
Once a lump of food enters the stomach, it remains there for 3-5 hours, during which time it is subjected to mechanical and chemical treatment. Digestion in the stomach begins with exposure of food to gastric juice and the hydrochloric acid that is present in it, as well as pepsin.
As a result of digestion in the human stomach, proteins are digested with the help of enzymes into low molecular weight peptides and amino acids. The digestion of carbohydrates, which begins in the mouth, stops in the stomach, which is explained by the loss of amylases’ activity in an acidic environment.
Digestion in the stomach cavity
The process of digestion in the human body occurs under the influence of gastric juice containing lipase, which is capable of breaking down fats. In this case, great importance is given to the hydrochloric acid of gastric juice. Under the influence of hydrochloric acid, the activity of enzymes increases, denaturation and swelling of proteins is caused, it turns out bactericidal effect.
The physiology of digestion in the stomach is that food enriched with carbohydrates, which remains in the stomach for about two hours, undergoes an evacuation process faster than food containing proteins or fats, which lingers in the stomach for 8-10 hours.
Food that is mixed with gastric juice and partially digested, being in a liquid or semi-liquid consistency, passes into the small intestine in small portions at simultaneous intervals. In which department does the digestion process still take place in the human body?
Digestive department - small intestine
Digestion in the small intestine, into which the bolus of food enters from the stomach, has the most important place, from the point of view of the biochemistry of the absorption of substances.
In this section, intestinal juice consists of alkaline environment due to the arrival of bile, pancreatic juice and secretions of the intestinal walls into the small intestine. The digestive process in the small intestine does not go quickly for everyone. This is facilitated by the presence of an insufficient amount of the enzyme lactase, which hydrolyzes milk sugar associated with the indigestibility of whole milk. During the digestion process in this part of a person, more than 20 enzymes are consumed, for example, peptidases, nucleases, amylase, lactase, sucrose, etc.
The activity of this process in the small intestine depends on the three parts passing into each other, of which it consists - duodenum, jejunum and ileum. IN duodenum Bile formed in the liver is released. Here food is digested thanks to the pancreatic juice and bile that act on it. This colorless liquid contains enzymes that promote the breakdown of proteins and polypeptides: trypsin, chymotrypsin, elastase, carboxypeptidase and aminopeptidase.
Role of the liver
An important role in the process of digestion in the human body (we will briefly mention this) is played by the liver, in which bile is formed. The peculiarity of the digestive process in the small intestine is due to the assistance of bile in emulsifying fats, absorbing triglycerides, activating lipase, also helps stimulate peristalsis, inactivate pepsin in the duodenum, has a bactericidal and bacteriostatic effect, increases hydrolysis and absorption of proteins and carbohydrates.
Bile does not contain digestive enzymes, but is important in the dissolution and absorption of fats and fat-soluble vitamins. If bile is not produced enough or is secreted into the intestines, then the processes of digestion and absorption of fats are disrupted, as well as an increase in their excretion in their original form with feces.
What happens in the absence of a gallbladder?
The person is left without the so-called small sac, in which bile was previously deposited “in reserve.”
Bile is needed in the duodenum only if there is food in it. And this is not a constant process, only during the period after eating. After some time, the duodenum is emptied. Accordingly, the need for bile disappears.
However, the work of the liver does not stop there; it continues to produce bile. It is for this purpose that nature created the gallbladder, so that the bile secreted in the intervals between meals does not deteriorate and is stored until the need for it arises.
And here the question arises about the absence of this “bile storage”. As it turns out, a person can do without a gallbladder. If the operation is performed on time and other diseases associated with the digestive organs are not provoked, then the absence of a gallbladder in the body is easily tolerated. The timing of the digestion process in the human body is of interest to many.
After surgery, bile can only be stored in bile ducts. After bile is produced by liver cells, it is released into the ducts, from where it is easily and continuously sent to the duodenum. Moreover, this does not depend on whether the food is taken or not. It follows that after the gallbladder has been removed, food must be taken frequently and in small portions for the first time. This is explained by the fact that there is not enough bile to process large portions of bile. After all, there is no longer a place for its accumulation, but it enters the intestine continuously, albeit in small quantities.
It often takes time for the body to learn to function without a gallbladder and to find the necessary place to store bile. This is how the digestion process works in the human body without a gallbladder.
Digestive department - large intestine
Leftovers undigested food are advancing in colon and stay there for approximately 10 to 15 hours. Here the following digestive processes take place in the intestines: absorption of water and microbial metabolization of nutrients.
In the digestion that occurs in the large intestine, food plays a huge role, which includes indigestible biochemical components: fiber, hemicellulose, lignin, gums, resins, waxes.
The structure of food affects the speed of absorption in the small intestine and the time of movement through the gastrointestinal tract.
Some of the dietary fiber that is not broken down by enzymes belonging to the gastrointestinal tract is destroyed by microflora.
The large intestine is the place of formation of feces, which includes: undigested food debris, mucus, dead cells of the mucous membrane and microbes that continuously multiply in the intestines and which cause the processes of fermentation and gas formation. How long does the digestion process in the human body last? This is a common question.
Breakdown and absorption of substances
The absorption process occurs throughout the entire digestive tract, which is covered with hairs. On 1 square millimeter of mucous membrane there are about 30-40 villi.
In order for the process of absorption of substances that dissolve in fats, or rather fat-soluble vitamins, to occur, fats and bile must be present in the intestines.
Absorption of water-soluble products such as amino acids, monosaccharides, mineral ions occurs with the participation of blood capillaries.
U healthy person The entire digestion process takes from 24 to 36 hours.
This is how long the digestion process in the human body lasts.
Every living organism, be it bacteria, reptiles or humans, has adapted to life throughout its development largely due to the ability to absorb nutrients from the environment. What are the features of food digestion in humans and animals, what are the principles of separate nutrition based on? You will learn about this from our publication.
For digestion various types food needs different times.
IN at different ages The functioning of the human digestive tract has its own characteristics, which is most clearly expressed when comparing infants, older children and adults. The work of the digestive system begins in the baby in the womb. In the second half of intrauterine development, the fetus begins to absorb the so-called amniotic fluid with the nutrients present in it, which are absorbed into the blood in the stomach and intestines, and the secretory cells of the pancreas and stomach begin to produce insignificant amount enzymes.
In a newborn baby, all digestive organs are configured to absorb mother's milk. The salivary glands are still poorly developed, and active production saliva begins only by 4-5 months of life, but even at this time its volume is only 10% of that in an adult. Enzyme activity saliva is small, but it is enough for milk casein to be well absorbed.
Infants have a short esophagus and a horizontally located stomach with poorly developed sections, which explains the phenomenon of regurgitation after feeding. In addition, in small children in the stomach fewer glands, than in an adult, the acidity of the digestive secretion is lower. The digestive enzyme pepsin in infants is capable of processing only milk protein. To digest mother's milk, a baby needs about 2-3 hours, and cow's milk - up to 4 hours, which is why the latter is absorbed worse.
By the age of seven, the number of glands in the stomach increases, and the volume of the stomach increases to 1 liter. In children under the age of 10-12 years, intensive absorption of nutrients occurs in the stomach, while in adults this process for the most part occurs in the small intestine. The acidity of gastric juice corresponding to an adult is achieved by the age of 15 due to an increase in the production of hydrochloric acid. The activity and concentration of digestive enzymes is highest in the period from 20 to 40 years, then it decreases. In men, the concentration of hydrochloric acid is higher than in women, but after 75-80 years this figure levels out between the sexes. In old age, both the activity of pancreatic secretions and the intensity of absorption of digested food decrease.
Digestion time for different foods
Let us give the time it takes to digest various foods in the stomach of an adult. Knowing it, you can competently build your daily menu and prevent intestinal blockage. The data is summarized in the table below.
| Digestion time in minutes | Products |
| 15-25 | Vegetable or fruit juice Vegetable broths |
| 20-30 | Semi-liquid low-calorie food: fruit puree, pureed vegetables Grape Citrus Melon crops: melon and watermelon |
| 30-40 | Fresh apples, peaches and pears Cherries and cherries Cucumbers and tomatoes Vegetable salads not seasoned with oil Leafy greens, celery Bell pepper Stewed spinach and white cabbage Most seafood Cod and flounder Egg yolk |
| 45-50 | Stewed or boiled zucchini Cauliflower and Brussels sprouts Young boiled corn Radish and turnip Egg |
| 60 | Potato tubers Jerusalem artichoke |
| 90-100 | Low-fat Low-fat cheese and cottage cheese Yogurt, kefir Plain and brown rice Buckwheat porridge without meat |
| 100-120 | Cottage cheese normal fat content Soybeans and products made from it Lentils Pumpkin and sunflower seeds Chicken without skin |
| 150-180 | Walnuts Unsalted unroasted peanuts Brazilian nut |
| 180-270 | Beef meat Mutton |
| 240-300 | Hard fat cheese |
In terms of speed, food is digested in this order: carbohydrates, proteins, fats. Raw proteins of animal origin are processed much faster than boiled ones. The longer the heat treatment takes, the worse the process is underway digestion, which is why a soft-boiled egg is digested faster than a hard-boiled one. This table will help you in correctly compiling your menu. For example, potatoes are healthier to eat with lean fish, chicken meat with lentil porridge, etc. In addition, if you adhere to the rule that you cannot eat until your stomach is empty of food, you can lose weight without strict diets overweight and restore normal functioning of the gastrointestinal tract.
Principles of separate power supply
The ideal option for the stomach and the body as a whole is to eat foods with the same digestion time at one meal, and each next appointment should be carried out after complete absorption of the previous portion. An inconsistent diet containing dishes with many ingredients is not considered optimal and leads to cluttering of the intestines and increased decay processes in it, leading to the accumulation of toxins.
Having eaten food with certain time digestion, you must wait until this process is completed completely and the stomach and intestines are empty. During this time, the food will have time to go through a full decomposition cycle. Only after this is it allowed to consume foods that are digested slowly, and vice versa. If you do not follow the sequence of eating foods with different digestion times, then fruits, cooked and raw vegetables, starchy and protein food they begin to wander together. In this case, gases, acids and even alcohol molecules are released, causing indigestion and clogging.
The principles of separate nutrition are based on consuming only compatible products, and between meals you must wait at least 2 hours. The exception is fruits, after which you can eat other food within 20-30 minutes.
An important rule is that you must first eat liquid food, and avoid drinking drinks during and after meals. You need to chew food thoroughly, until it reaches a consistency close to liquid. Remember that the fewer types of food you mix, the better it is digested, and the less prone you will be to overeating.
Features of digestion in animals
The process of digestion and assimilation of food occurs differently in different animals, let's see this using the example of rabbits, birds, dogs and hamsters.
Rabbits are animals that need a large amount of fiber, and they can eat up to 30 times per day, while young animals are more voracious, for example, small month-old rabbits can eat up to 55 times per day. The structure of their gastrointestinal tract is also very interesting, since the cecum is 7-9 times larger in volume than the stomach. This feature allows you to process huge quantities plant fibers, because such a large appendix of rabbits contains microorganisms that decompose cellulose. Rabbits have high acidity of gastric secretions, and their production occurs constantly, even at night, and not just during meals. Another interesting feature is caprophagy - this is when rabbits eat their night feces, which differs from their daytime feces. Thanks to this phenomenon, the animals’ bodies receive more B vitamins. Time complete passage feed through the rabbit's gastrointestinal tract is up to 48 hours.
Birds are endowed with a two-chamber stomach, which is divided into two sections. Each performs its own function: the first produces gastric juice, and the second works like a millstone; it always contains a lot of small pebbles and grains of sand. In terms of time, grains take the longest to digest – 6-12 hours; insects take 30-60 minutes to process. For chicken, for example, grain can be digested for up to a day, and for sparrows - up to 6 hours.
But in ruminants, the digestive system is more complex, and the stomach consists of several chambers at once: the rumen, the mesh, the book and the stomach itself, which is called the abomasum. The rumen is the largest part, and individual species, for example, in cows, can reach incredible volumes - 110-145 liters. Digestion of food is also not complete without regurgitation, when food that has entered the rumen again enters the oral cavity for more thorough grinding. It takes up to 4-6 hours to digest the food.
What interesting things can you say about dogs? To completely process the food they eat, they need from 6 to 16 hours, depending on the type of food. These four-legged friends have a peculiarity, which is that the concentration of acid in the gastric juice will be different depending on what food you offer your pet. The secretion will be most sour when eating meat, less when eating bread. But the strength of the juice, due to a large number of enzymes, is higher when the dog eats bread, and for meat, although the acidity is the highest, there are fewer enzymes in the juice. It is also interesting that dogs produce thin saliva for bread, and thicker saliva for meat.
Animals with very sensitive digestion are everyone's favorite hamsters, which cannot be fed with just anything. For example, soybean caught in gastrointestinal tract hamster, can cause ascites, and the acid of citrus fruits is harmful to the gastric mucosa of these animals. Persimmons can cause diarrhea in your hamster, sweet foods often lead to diabetes, and salty foods impair kidney function. Vegetables and not very sweet fruits, raw nuts and corn, beans, water porridge and even baby food. Interestingly, hamsters’ teeth lack a protective layer of enamel, this is another reason why animals should not be given sweets. The hamster's stomach accepts raw apples, pears and carrots well. Also digestive enzymes the animal copes with protein food, and every three to four days the animal can be fed with protein chicken egg, lean boiled fish or beef without salt. For the assimilation of products in digestive system It takes a hamster 3-4 hours.
This is interesting
The process of digesting food begins before it enters the stomach, since the salivary and digestive glands are activated when you are hungry or feel the aroma delicious dish or see him. This phenomenon is based on conditioned reflexes.
The human salivary glands produce more than 1.5 liters of saliva per day. Incredibly, the average person consumes up to half a ton of food per year. The total surface area of the small intestine is 250 m2.
The main percentage of the hormone responsible for joy and high spirits is produced in the stomach, and it is called serotonin. Digestive juices are unable to digest chewing gum, therefore, when passing through the stomach and intestines, it remains unchanged, and can cause blockage of the intestinal lumen.
Video about separate meals from the Malakhov+ program
Digestion- This is the process of chemical and mechanical processing of food, during which it is digested and absorbed by the cells of the body. Digestive pigments process incoming food and break it down into complex and simple food components. First, proteins, fats and carbohydrates are formed in the body, which in turn become amino acids, glycerol and fatty acids, monosaccharides.
The components are absorbed into the blood and tissues, contributing to the further synthesis of complex organic substances necessary for the proper functioning of the body. Digestive processes important for the body for energy purposes. Through the digestion process, calories are extracted from food, which improves performance. internal organs, muscles, central nervous system. The digestive system is complex mechanism, which involves the human oral cavity, stomach and intestines. If the products are not digested correctly, and minerals will remain unchanged, it will not benefit the body. In a healthy person, all stages of the digestive process last for 24 to 36 hours. Let's study the physiology and features of the digestive process in order to understand how the human body works.
To understand what digestion is, it is necessary to consider the structure and functions of the digestive system.
It consists of organs and departments:
- oral cavity and salivary glands;
- pharynx;
- esophagus;
- stomach;
- small intestine;
- colon;
- liver;
- pancreas.
The listed organs are structurally interconnected and represent a kind of tube, 7–9 meters long. But the organs are laid out so compactly that with the help of loops and bends they are located from the oral cavity to the anus.
Interesting! Disturbances in the digestive system lead to various diseases. To ensure proper digestion, avoid Not rational nutrition, fatty foods, strict diets. Also, the organs are adversely affected by poor ecology, regular stress, alcohol and smoking.
The main function of the digestive process is to digest food and gradually process it in the body to form nutrients that are absorbed into the lymph and blood.
But besides this, digestion performs a number of other important tasks:
- motor or motor is responsible for grinding food, mixing with the secretions of the digestive glands and further movement through the gastrointestinal tract;
- secretory ensures the breakdown of nutritional components into mucous membranes, electrolytes, monomers and final metabolic products;
- absorption promotes the movement of nutrients from the tract cavity into the blood and lymph;
- protective consists of creating barriers using the mucous membrane;
- excretory removes from the body toxic substances and foreign bodies;
- endocrine produces biologically active substances to regulate digestive functions;
- Vitamin-forming ensures the production of vitamins B and K.
Digestive functions include sensory, motor, secretory and absorption. Among non-digestive tasks, scientists distinguish protective, metabolic, excretory and endocrine.
Features of the digestion process in the oral cavity
Stages of digestion in humans in the oral cavity, where the grinding of food for further processing begins - important processes. Products interact with saliva, microorganisms and enzymes, after which the taste of food appears and starchy substances are broken down into sugars. The processing process involves teeth and tongue. During coordinated swallowing, the uvula and palate are involved. They prevent food from entering the epiglottis and nasal cavity. The body analyzes incoming food, softens and grinds it. After this, it enters the stomach through the esophagus.
Digestive processes in the stomach
The stomach is located in the human body in the left hypochondrium under the diaphragm and is protected by three membranes: external, muscular and internal. The main function of the stomach is to digest food due to abundant capillary shunting blood vessels and arteries. It is the widest part of the digestive tract and can expand in size to absorb large amounts of food. During the processing of food in the stomach, the walls and muscles contract, after which it mixes with gastric juice. The process of chemical and mechanical treatment in the stomach lasts for 3 to 5 hours. Food is affected by hydrochloric acid, which is contained in gastric juice and pepsin.
Following the logical flow of the digestion process, proteins are processed into amino acids and low molecular weight peptides. Carbohydrates in the stomach stop being digested, so amylases lose their activity in an acidic environment. In the stomach cavity, due to hydrochloric acid, proteins swell and also provide a bactericidal effect. Peculiarity gastric process digestion is that foods rich in carbohydrates are processed briefly and after 2 hours they move on to the next process. Proteins and fats remain in the compartment for up to 8 – 10 hours.
How does digestion occur in the small intestine?
Partially digested food, along with gastric juice, moves in small portions into the small intestine. This is where more important digestive cycles take place. Intestinal juice consists of an alkaline environment due to the intake of bile, secretions of the intestinal walls and pancreatic juice. The digestion process in the intestines may slow down due to a lack of lactase, which hydrolyzes milk sugar. In the small intestine, more than 20 enzymes are consumed as a result of the digestion process. The work of the small intestine depends on the uninterrupted functioning of three sections that smoothly transform into each other: the duodenum, jejunum and ileum.
During digestion, the duodenum receives bile formed in the liver. Due to the compounds of bile and pancreatic juice, proteins and polypeptides are broken down into simple particles: elastase, aminopeptidase, trypsin, carboxypeptidase and chymotrypsin. They are absorbed into the intestines.
Liver functions
It should be noted the invaluable role of the liver, which produces bile during the digestion process. The work of the small intestine would not be complete without bile, as it helps emulsify fats, activate lipases and absorb triglycerides into the stomach. Bile stimulates perilstatics, enhances the absorption of proteins and carbohydrates, increases hydrolysis and promotes the inactivation of pepsin. Bile plays an important role in the absorption and dissolution of fats and fat-soluble vitamins. If there is not enough bile in the body or it is secreted into the intestines, then the digestive processes are disrupted, and fats are released in their original form when feces are released.
Importance of the Gall Bladder
In the gallbladder of a healthy person, reserves of bile are deposited, which the body uses when processing a large volume. The need for bile disappears after the duodenum is empty. But the liver's work does not stop when food is eliminated. It produces bile, storing it in the gallbladder so that it does not spoil and is stored until the need for it arises again.
If the gallbladder is removed from the body for some reason, its absence is easily tolerated. Bile is stored in the bile ducts and from there it is easily and continuously sent to the duodenum, regardless of the fact of food intake. Therefore, after surgery, you need to eat often and in small portions so that there is enough bile to process it. This is due to the fact that there is no more space to store leftovers, which means that the reserve stock is extremely small.
Features of the large intestine
Residues enter the large intestine undigested food. They stay in it for 10–15 hours. During this period, water absorption and microbial metabolization of nutrients occur. Thanks to the microflora of the large intestine, dietary fiber, which is classified as indigestible biochemical components, is destroyed in this section.
Among them are:
- wax,
- resin,
- gum,
- fiber,
- lignin,
- hemicellulose.
Forms in the large intestine feces. They consist of residues that have not been digested during digestion, mucus, microbes and dead cells of the mucous membrane.
Hormones that affect digestion
In addition to the main sections of the gastrointestinal tract, the quality and speed of the digestion process are influenced by biologically active substances.
| Name | Which department are they in? | Function |
| Gastroenteropancreatic endocrine system | endocrine system | produces peptide hormones |
| Gastrin | pyloric region | increased secretion of gastric juice, pepsin, bicarbonates and mucus, inhibition of gastric emptying, increased production of prostaglandin E |
| Secretin | small intestine | increased stimulation of bile production, increased alkali in pancreatic juice, provides up to 80% of bicarbonate secretion |
| Cholecystokinin | duodenum, proximal jejunum | stimulation of relaxation of the sphincter of Oddi, increased bile flow, increased pancreatic secretion |
| Somastostatin | pancreas, hypothalamus | decreased secretion of insulin, glucagon, gastrin |
As we see, the process of digestion in the human body is a complex system, without which human life is impossible. Proper absorption of food contributes to the quality of the body. Each organ that makes up the gastrointestinal tract plays an important role. To maintain health, it is necessary to adhere to the principles of rational nutrition and exclude bad habits. Then the mechanisms will work like clockwork.
Top 7 best drugs for weight loss:
| Name | Price |
| 990 rub. | |
| 147 rub. | |
| 990 rub. | |
| 1980 rub. 1 rub.(until 03/19/2019) | |
| 1190 rub. | |
| 990 rub. | |
| 990 rub. |
Also read:
