The life cycle of a human roundworm

The life cycle of a human roundworm has characteristic features, because its sole owner is a man. Therefore, changing the place of parasitization of this worm and contributes to certain symptoms and changes in internal organs. To fully diagnose and predict the development of a clinical picture in an ascarid attack, it is necessary to know certain features of its life cycle.

The sequence of events in the life cycle of ascarids

Ascaride belongs to the class of flatworms, it affects some features of its structure and life. First of all, it must be emphasized that the human ascaris is a heterozygous parasite, and this division into males and females requires special conditions not only for vital activity, but also for reproduction.

The sequence of events in the life cycle of ascarids starts from the moment eggs enter the human body. Further, according to the different forms of maturity of this worm, there are also different stages of development. Egg further in the process of growth turns into a small larva, then into a large larva, and only then into an adult.

All these stages are consistent and vary according to the place of stay in the human body. Therefore, several stages are isolated: intestinal, systemic (blood), parenchymal (hepatic and pulmonary) and then the entire cycle is repeated again after reinfection.

In general, the life cycle of a human roundworm takes about a year, but this is the case if one individual passes through all these stages. But most often several eggs fall and at the same time at each stage there can be several parasites, which leads to a long persistence of ascarids in the human body - this can last for years. At this time, ascaris releases its products of vital activity into the lumen of the intestine, which leads to the development of clinical symptoms.

When the female lays eggs, some of them undergo new development cycles, and some are excreted with feces, which can be determined in the analyzes. Given that the parenchymal phase of the life cycle can be in the form of an encapsulated larva, then there may not be any significant symptomatology. Therefore, when confirming the diagnosis of ascaridosis, it is necessary to take into account that in the human body this parasite can be at different stages of development, including parenchymal forms.

Characteristics of the life cycle of a human roundworm

The intestinal phase of the ascarid development begins when the pathogen enters the human body, namely into the small intestine. There is an activation of the eggs and they come out of their shell. Then a small form of larva forms, which is fixed to the inner wall of villi of the small intestine and penetrates into the blood vessels, namely the veins. Further, the life cycle scheme of the human roundworm consists in migration.

The small form of the larva entering the blood, is fed by serum of blood plasma, and then by red blood cells. The larva grows and grows in size. With blood flow, the larva passes through the portal vein system from the intestine to the liver, where the parasite can be screened in the form of encapsulated larvae. In the liver, the ascarid larvae can be located around the hepatic beams and squeeze the intrahepatic bile ducts.

Then there are symptoms from the liver in the form of violations of the outflow of bile. But this arrangement may not affect the bile duct and symptoms may not be. Further, larvae with blood flow from the liver migrate along the inferior vena cava to the right ventricle of the heart and enter the lungs through the system of pulmonary arteries.

Ascaride has its own characteristics, since for life it needs oxygen. That is why the lungs of a person are one of the intermediate organs that the ascaris goes through during its life. Lungs can also be encapsulated in the lungs, but with this localization the asymptomatic flow is more typical. This is due to the fact that the lungs do not have pain receptors, there may be only minor painful sensations in the localization of the larvae near the parietal pleura. Such an arrangement can cause a reflex cough, which in turn facilitates further migration of the parasite.

With the cough of ascarid falls into the pharynx, and then again into the intestine - so the intestinal phase repeats. But in this case, the individuals are fully mature forms, these are worms that reach several dozen centimeters and can reproduce. So the whole life cycle of the roundworm repeats itself and the number of individuals increases every time. Therefore, taking into account the difficult way of migration of the roundworm, it is recommended that ultrasound of the liver and lungs be used in establishing the diagnosis, which makes it possible to identify the pathogens of the pathogen and to conduct adequate treatment.

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