Can you complete this task: "List the human digestive glands"? If you doubt the exact answer, then our article is exactly for you.
Classification of glands
Glands are special organs that secrete biologically active substances - enzymes. They are biological catalysts that speed up the process of chemical reactions, but are not part of its products. They are also called secrets.
Distinguish glands of internal, external and mixed secretion. The first release secrets into the blood. For example, the pituitary gland, which is located at the base of the brain, synthesizes growth hormone that regulates this process. The adrenal glands secrete adrenaline. This substance helps the body cope with stressful situations, mobilizing all its forces. The pancreas is mixed. It produces hormones that enter both the blood and directly into the cavity of internal organs (in particular, the stomach).
Digestive glands such as salivary glands and liver are exocrine glands. In the human body, they also include lacrimal, milk, sweat and others.
Human digestive glands
These organs secrete enzymes that break down complex organic substances into simple ones that can be absorbed by the digestive system. Passing through the tract, proteins are broken down into amino acids, complex carbohydrates into simple ones, lipids into fatty acids and glycerol. This process cannot be carried out due to the mechanical processing of food with the help of teeth. Only the digestive glands can do this. Let's consider the mechanism of their action in more detail.
Salivary glands
The first digestive glands at their location in the tract are salivary. A person has three pairs of them: parotid, submandibular, sublingual. When food enters the oral cavity, or even when it is seen, saliva begins to flow into the oral cavity. It is a colorless mucus-sticky liquid. It consists of water, enzymes and mucus - mucin. Saliva has a slightly alkaline reaction. The enzyme lysozyme is able to neutralize pathogens and heal wounds of the oral mucosa. Amylase and m altase break down complex carbohydrates into simple ones. This is easy to check. Put a piece of bread in your mouth, and after a short time it will turn into a crumb that can be easily swallowed. Mucus (mucin) coats and moisturizes food pieces.
The chewed and partially digested food is transported through the pharynx through the esophagus to the stomach, where it is further exposed.
Digestive glands of the stomach
In the mostThe glands of the mucous membrane of the expanded part of the digestive tract secrete a special substance into its cavity - gastric juice. It is also a clear liquid, but with an acidic environment. The composition of gastric juice includes mucin, the enzymes amylase and m altase, which break down proteins and lipids, and hydrochloric acid. The latter stimulates the motor activity of the stomach, neutralizes pathogenic bacteria, and stops putrefactive processes.
Different foods are in the human stomach for a certain time. Carbohydrate - about four hours, protein and fat - from six to eight. Liquids do not linger in the stomach, except for milk, which turns into curd here.
Pancreas
This is the only digestive gland that is mixed. It is located under the stomach, which determines its name. It secretes digestive juice into the duodenum. This is the external secretion of the pancreas. It releases the hormones insulin and glucagon directly into the blood, which regulate carbohydrate metabolism in the human body. In this case, the organ works as an endocrine gland.
Liver
Digestive glands also perform secretory, protective, synthetic and metabolic functions. And it's all thanks to the liver. It is the largest digestive gland. Bile is constantly produced in its ducts. It is a bitter greenish-yellow liquid. It consists of water, bile acids and their s alts, as well as enzymes. The liver secretes its secret into the duodenum, in whichthere is a final splitting (emulsification) of fats and disinfection of substances harmful to the body.
Since the breakdown of polysaccharides begins already in the mouth, carbohydrate foods are the most easily digestible. However, everyone can confirm that after a vegetable salad, the feeling of hunger comes very quickly. Nutritionists advise eating protein foods. It is energetically more valuable, and the process of its splitting and digestion lasts much longer. Remember that nutrition must be balanced.
Now can you list the digestive glands? Can you name their functions? We think so.
