Parasitic protozoa. Prasit: description, examples

Among the dangerous organisms that inhabit the human being and harm its health, a significant place is occupied by parasitic protozoa. These are unicellular animals that have adapted to existence at someone else's expense. They are quite numerous, in all, there are about 30 different species of individuals that specialize specifically on humans. Even more occurs in the organisms of other vertebrates and invertebrates.

Parasitic protozoa: structural features

Externally and internally, these organisms have exactly the same structure as all other unicellular organisms. They have only one structural unit, but it is capable of performing all the vital functions necessary for normal life. Namely:

• Grows and develops;
• Multiplies;
• Eats;
• Breathes;
• Has excitability and irritability;
• Moves.

Therefore, we can say with confidence that parasitic protozoa are completely independent, whole living organisms. Their differences from all other unicellular ones are that they lost the digestive vacuole in connection with the parasitic way of life, and also the contractile one. In addition, organoids of movement are most often deprived.

Propagate quickly enough, asexually. The maternal cell simply, upon reaching maturation, breaks up into several daughter cells. They lead an independent lifestyle immediately after education.

How do parasites feed in the host? It depends on the individual characteristics of each species, but mostly their food is blood or intestinal contents. Absorb substances they entire surface of the body due to the reduction of the vacuole.

Classification and representatives of simple parasites

Classify the various representatives of the organisms under consideration in the following way.

All these organisms are the cause of protozoal diseases of man. All of them are very parasitic protozoa, very dangerous for life and health. The table includes only the most common representatives. In fact, there are more rare, there are a lot of them.

Leishmania

To date, the figure that reflects the number of people affected by this parasite is simply terrible - 12 million. This oval form of immobile intracellular protozoan representative has a small flagellum. However, it moves very slowly and for short distances.

Settling inside the host cells, which for leishmania is an insect and a mammal, including a man, they cause a gradual withering away of the structure. At the person on a skin, in that place where leishmanias live, the open yawning ulcer forms, constantly decaying. This disease is called a rubber ulcer or Baghdad ulcer. It is treated very difficultly and for a long time, with surgical intervention.

One-celled mosquitoes carry this group, so the centers of leishmaniasis are found in the countries of the tropics and subtropics.

Ljambley

The class of parasitic protozoans, which include Giardia - Flagellar. The most dangerous representative for people is the intestinal lamblia, which causes a dangerous disease - giardiasis.

Adult individuals parasitize in the upper part of the intestine. It is here that they absorb all the nutrients that people consume with pinocytosis. Also this organism is able to form cysts. In this state, they may experience exposure to ultraviolet radiation and exposure to toxic substances. However, low and high temperatures are deadly for them.

Cysts are located in the large intestine, therefore they are excreted with solid products of vital activity. Infection occurs through dirt, water. Therefore, personal hygiene rules are especially important in the prevention of giardiasis.

What is dangerous about this parasite? In the process of life, lamblia secretes toxic decomposition products, which strongly poison the body from the inside.

Parasitic rhizomes

This class includes different types of amoeba:

• Intestinal;
• Dysentery;
• Oral.

These parasitic protozoa cause dangerous diseases in people who in some cases can end even with death.

Dysentery amoeba is a representative of hot countries. It is in them that it is the most common parasite. Its feature, like all amoebaids, is the absence of shell and skeletal formations. Therefore, it moves by means of pseudopods. Propagated by simple division. It is able to form cysts, also living in the human body. Within this structure, multiple division occurs.

Causes a disease amebiasis. Affected internal walls of the intestine, on which amoeba leave bleeding ulcers. A person has a bloody liquid stool, pain inside the body. Diagnosing a dysenteric amoeba is difficult. Therefore, she is a very dangerous representative of parasites.

Unlike the considered form, intestinal amoeba is present in the body of almost every person and lives with it in harmony. Does not emit toxic substances and does not penetrate the walls of the intestine. Therefore, special discomfort and harm to health does not cause.

Oral amoeba is the inhabitant of plaque and caries formations. Feeds on bacteria, can use red blood cells. Its exact meaning for man is not yet clear.

Balantidium coli

This organism is a representative of the class of the Infuzoria. A fairly large oval single-celled organism that settles in the intestines of people. It is here that he digs and digs the wall of the organ, causing the appearance of bleeding, suppurating wounds. Cysts of this protozoon easily fall into the bloodstream. So there is a resettlement throughout the body.

How do parasites of this species feed? In the same way as other representatives. Absorb nutrients in the human intestine with the entire surface of the body. Propagates by asexual division into several cells. Forms cysts that also parasitize a person.

Cyst infection of the simplest occurs when contact with mucous membranes with dirty hands, when drinking raw water. The disease caused by these creatures is called balantidiosis. It is accompanied by vomiting with blood, diarrhea, weakness, severe colic in the abdominal cavity.

Trichomonases

Parasitic protozoans are organisms that live in the genitourinary system of women and men. They can not harm themselves, but they are a hiding place for pathogenic bacteria and other pathogenic organisms. Capable of disguising themselves as human cells, so the immune system itself can not destroy them.

The disease that causes the trichomonas directly, is called trichomoniasis. It is sexually transmitted and threatens infertility to both men and women.

Symptoms of the disease in children

The worst thing is when there are parasites in children. Symptoms of their occurrence are as follows:

• General weakness;
• Fatigue;
• pallor;
• headache;
• Decreased appetite;
• Poor sleep;
• irritability;
• Loose stools;
• Vomiting and others.

The most important thing is to pay attention to them and do not let things go by themselves. Moreover, according to recent reports, in the first place among diseases are parasites in children. Symptoms - a sure sign that you should think about and see a doctor.