Human roundworm. Ascaris human Ascaris human representative of roundworms presentation

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to develop knowledge about the structure, life processes, lifestyle and adaptability of roundworms to their habitat; develop the ability to highlight the main points, compare, and work independently with a textbook; carry out hygiene education. Tasks:

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Life cycle of the liver fluke The liver fluke lives in the ducts of the liver cattle. Its development includes a change of owners and alternation of generations. The fluke eggs leave the liver into the host's intestines and then, with feces, out. Moreover, for their development, they must certainly get into water, which, obviously, does not always happen. In the water, a larva with cilia emerges from the egg, which further development must penetrate the body of the pond snail. Here the larva not only grows, but also reproduces, producing several more larvae of the next generation. These second generation larvae emerge from the pond snail's body into the water. They can actively swim using their tail. Spreading throughout the pond, they eventually attach to the leaves aquatic plants, become covered with a membrane and become motionless, that is, they turn into a cyst. They can remain in this state for a long time. Livestock becomes infected with liver fluke by drinking water or eating grass with its cysts. In the intestine, the cyst bursts, the young fluke comes out and penetrates the liver. Thus, the development of the fluke depends on many accidents. Therefore, the fluke produces a huge number of eggs. Its reproduction also occurs in the larval stage.

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Habitat and external structure roundworms. Roundworms are white or yellowish worms that live in the small intestine of the human body - roundworms. The body of the female reaches: (20–40 cm) males (15–20 cm), the anterior and posterior ends are pointed. With them, the roundworm rests against the intestinal wall and is held there. They do not have special attachment organs like flatworms. At the anterior end of the body is the mouth, and at the posterior end is the anus. The integument of the roundworm is devoid of cilia, its body is covered with a dense cuticle. It protects against mechanical damage and prevents its digestion in the human intestine.

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Internal structure roundworms 1 – ectoderm 2 – longitudinal muscles 3 – ovary 4 – endoderm 5 – intestinal lumen 6 – body cavity 1 2 3 4 5 6

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“Smile” - Teeth. Changing teeth is a natural process that occurs in all people. How to take care of your teeth? Smile! Course for junior schoolchildren on health education. Toothbrush located along the gum line. “If you just laugh, then miracles will happen - From smiles, both your eyes and the skies will become clear. The brush movements are from top to bottom. 2. Clean the inner surface of the tooth.

“Biosocial Man” - Thinking. A condition, a prerequisite for human existence. Biosocial nature of man. Process individual development a person is based on two types of information. Instincts. Photos and pictures used. The essence of man. Biological in man. The ability for conscious, purposeful activity.

“Influence on the human body” - Brain. Digestive system. Why is the material I studied valuable to me? Fatty degeneration of the heart Dilatation of blood vessels Increased heat transfer by the body. The effect of ethanol on human organ systems. The cardiovascular system. At the heart of the work nervous system lies the reflex mechanism.

“Human Sciences” - Founders of immunology. Increase in brain volume and development of mental activity. Differences between humans and animals. William Harvey 1587-1657. Hippocrates 460-377 BC C. Darwin 1809-1882. Lesson topic: The formation of human sciences. The founders of immunology E. Jenner (1749-1823) Louis Pasteur (1822-1895.

“Human height” - Number of births. Energy progress in evolution follows the allometric growth law y = 16203x-1.5 R2 = 0.94. But are there any examples of growth according to the hyperbolic law in biology? The number of animal species depending on the mass of individuals. Micrograms! “Our great-grandchildren will die not from hunger, but from stampede” (von Foester joke).

Ascariasis may be second only to enterobiasis in its distribution. Ascariasis is caused by worms - parasites that can be found in the human intestines. At the same time, the length of a male roundworm is 25 centimeters, a female is 40 centimeters. Roundworms have absolutely no organs of attachment, they simply move towards food - this is how they are retained in the intestines. The roundworm has a fusiform body; on top it is covered with a rather dense cuticle, which protects the parasite from mechanical influences, for example, it prevents the parasite from being digested in the human gastrointestinal tract. Roundworms reproduce sexually. The fertilized female at the border of the anterior and middle third of the body has an annular depression - a constriction.

Human roundworm Full development Ascaris infection passes without a host at all: the eggs reach maturity perfectly in the soil. The larvae appear on the 1st day. They, unlike adults, need oxygen. Eggs enter the human intestines from the soil, through water, dirty vegetables and fruits. There the larvae pass through the intestinal wall and enter the blood vessels, and then migrate throughout the body. Together with the blood flow, they can penetrate into the liver, right atrium, ventricle of the heart, and from there into the pulmonary artery and capillaries of the pulmonary alveoli. Actively moving, they literally drill into the walls of the capillaries and enter the cavity of the alveoli, bronchi and trachea. As a result, a person develops a cough. And when you cough, the larvae enter the throat. Upon secondary ingestion by the host, they enter the small intestine, where they reach sexual maturity. This entire process takes two weeks. And the roundworm turns into an adult in a matter of days. In total, adults live for months.

The roundworm development cycle As a rule, this stage of roundworm development ends within a day, when a mature larva is formed in the egg and it becomes invasive, that is, dangerous to humans. As soon as an infective egg enters the human body (with food, through unwashed hands, contaminated water, etc.), under the influence of a chemical environment gastrointestinal tract human egg shells dissolve and the larva enters the intestines, its favorite place a habitat. Sometimes the microscopic larva does not remain in the intestine, but migrates along circulatory system. It is not uncommon for roundworms to large quantities found in the ventricle of the patient’s heart, in the alveoli, bronchi and trachea, in the liver and even in the brain. Since the human roundworm, like all nematodes, does not have intermediate host, larval development occurs directly in external environment. All she needs is access to oxygen, sufficient humidity and a temperature close to room temperature.

Human roundworm Roundworms poison the human body with the products of their metabolism - they are poisonous to humans. This poisoning manifests itself in indigestion, pain in the intestines, loss of appetite, and decreased performance. Almost all stages of development of roundworm in the human body cause allergic reactions and damage to liver and lung tissue. To prevent ascariasis, you must follow basic rules of personal hygiene: wash your hands, wash vegetables and fruits, and also protect food from cockroaches, flies and other insects.

Pinworm The disease caused by pinworms is called “enterobiasis”. This is a very common disease, most often found in children. Many parents are familiar with small round worms (8-10 cm), which they have more than once found on their child’s skin and clothes. Enterobiasis is a disease of dirty hands. The pinworm is a small worm white. The length of the female reaches 10 cm, the male 5 mm. The posterior end of the body of the male is twisted on the ventral side, in the female it is awl-shaped and pointed.

Pinworm At the anterior end of the body of pinworms there is a swelling that surrounds the mouth opening and is called a “vesicle”. With its help, the pinworm attaches to the intestinal wall. Reproductive system pinworms are typical of the entire class of nematodes. Worms feed on intestinal contents and are able to ingest blood. Pinworm eggs are oval, with a colorless shell. One side of the oval is flattened, the other is convex. Pinworms live in the cecum and appendix of humans without causing any painful symptoms. When an inflamed appendix is ​​removed, these helminths are sometimes found in it, but there is no evidence of their participation in inflammatory process still no.

Enterobiasis A person experiences severe itching and scratches his skin, and pinworm eggs get on his hands and under his nails. After this, they are easily transferred to toys and other things, and also enter the person’s mouth. For further development of eggs, a special microclimate is required with a temperature of 34-36 ° C and high humidity(70-90%). Suitable conditions for this are in the human perineum and perianal folds. There, the eggs mature within 4-6 hours. Once under the owner’s nails, the eggs also find optimal conditions there for further development. In the intestines, larvae mature inside the eggs, which develop into adults within 2-4 weeks. Then the whole cycle repeats again.

Pinworm It is clear that in human infection with pinworms main role perform with dirty hands. Therefore, children most often suffer from enterobiasis. younger age, visiting preschool institutions. The main sign of the presence of pinworms in the body is itching in the anus. This phenomenon occurs most often in the evening and at night. Parents should carefully monitor the child's sleep and, if this sign occurs, immediately take measures to carry out deworming. It must be remembered that stool examination does not provide results for diagnosing enterobiasis, since pinworms lay eggs outside the exit from the rectum. An accurate diagnosis can only be made by examining a scraping from the skin near the anus. Females usually die after laying eggs.

The life cycle of the pinworm Enterobiasis, the disease of dirty hands, begins with the fertilization of the female in the intestine of the host. Most often, pinworms appear in young children, but this does not mean that adults cannot get sick. The female pinworm crawls out of the anus and lays eggs (up to a dozen) on the skin of the buttocks and thighs, gluing them.

Whipworm This helminth ranks third in frequency of distribution. Infestation with whipworm causes trichuriasis. The body length of the female whipworm reaches 5.5 cm, the male 4-5 cm. The body shape of this helminth is quite peculiar: the head end is sharply narrowed and looks like a thread or hair, and the rear end is thickened.

Whipworm development cycle The life cycle of this helminth is simple. The fertilized female lays eggs directly in the intestine, from where they are released along with feces. Larvae develop from eggs directly in the external environment. At optimal conditions(temperature 26-28° C) eggs mature within 4 weeks. The whipworm does not have an intermediate host. Classic ways of infection with trichuriasis: unwashed fruits and vegetables, dirty hands, unboiled water.

Whipworm Helminths enter the human body through dirty hands, unwashed vegetables and fruits and water. The eggs enter the intestines, reach the cecum and develop into mature individuals. Whipworms can live in the human body for 5 years. The occurrence of symptoms of trichuriasis depends on the degree of infection. Single helminths do not cause any symptoms. With mass infection, the functioning of the digestive tract is disrupted, loss of appetite occurs, pain, diarrhea and constipation appear. Disruptions in the activity of the nervous system also begin, manifesting themselves in dizziness and convulsive seizures. In places of traumatic damage to the intestinal walls during trichocephalosis, a secondary infection can develop, and appendicitis can occur as a complication.

Trichinella Trichinosis can threaten lovers of brisket, pork hams and other types of half-cooked pork meat. In infected pork meat you can find small oval capsules containing small (0.5 mm) Trichinella (or Trichina) worms twisted into a spiral. Their life cycle can occur in the intestines and muscles. Pork meat can contain up to 15 thousand Trichinella per 1 kg. Trichinas retain their viability under these conditions for up to 20 years or more.

Trichinella Mature Trichinella individuals live in the small intestine for about 4 weeks. The capsules, entering the human intestine, are transformed into young Trichinella, which, as they grow older, fertilize the females and die. Females penetrate the lymphatic vessels through the intestinal epithelium and give birth there to up to 2000 live larvae each. Trichinella larvae are carried through the bloodstream throughout the body and stop in the skeletal muscles in certain groups muscles. Most often, the larvae infect the diaphragm, masticatory, intercostal and deltoid muscles. Even the muscles of the eyes can become their habitat.

Trichinella The capsule shell dissolves in the animal's intestines, and within 2-3 days the larvae are released and very quickly reach sexual maturity. Then the males fertilize the females and a new generation of larvae is born. Thus, each organism infected with Trichinella becomes their definitive host, and for larvae born by females, intermediate Trichinosis is a severe disease with high percentage mortality (up to 30% of infected people). The main symptoms of this helminthiasis are similar to the symptoms of typhoid fever: headache, diarrhea, swelling of the face, aches throughout the body, fever up to 40 ° C. The fight against trichinosis consists of exterminating rats living in pigsties and checking the meat going on sale. You should not buy meat products from dubious sellers; you must pay attention to the presence of brands on carcasses and hams

Strongyloidiasis Infection with strongyloidides can also occur in two different ways: actively and passively. In the first case, the filariform larvae themselves penetrate into the human body, “biting” through the skin, and in the second they enter the gastrointestinal tract. intestinal tract along with water and food (unwashed vegetables, fruits, etc.). Depending on the method of penetration, the duration of migration of larvae along to the human body can range from 17 to 27 days. After a month, they usually turn into adults and begin to actively reproduce. The lifespan of adult strongloidids does not exceed several months. However, due to constant self-infection, treatment of strongyloidiasis is an extremely difficult task: parasites remain in the host’s body for years and decades, during which they continuously destroy all its organs and tissues. Strongyloidiasis At the initial stage (with a small number of helminths in the body), the disease is practically asymptomatic. Skin rashes, slight swelling, and allergic reactions are possible. Very often, a characteristic “linear urticaria” appears on the body, in the place where clothing fits closely to the skin, redness and swelling suddenly form in the form of a cord, which disappears without a trace after hours.

Human roundworm.

The full development of the roundworm takes place without a host at all: the eggs reach maturity perfectly in the soil. Larvae appear on the 16th-17th day. They, unlike adults, need oxygen. Eggs enter the human intestines from the soil, through water, dirty vegetables and fruits. There the larvae pass through the intestinal wall and enter the blood vessels, and then migrate throughout the body. Together with the blood flow, they can penetrate into the liver, right atrium, ventricle of the heart, and from there into the pulmonary artery and capillaries of the pulmonary alveoli. Actively moving, they literally drill into the walls of the capillaries and enter the cavity of the alveoli, bronchi and trachea. As a result, a person develops a cough. And when you cough, the larvae enter the throat. Upon secondary ingestion by the host, they enter the small intestine, where they reach sexual maturity. This entire process takes two weeks. And the roundworm turns into an adult in 70-75 days. In total, adults live 10-12 months.

The roundworm development cycle As a rule, this stage of roundworm development ends on the 16-17th day, when a mature larva forms in the egg and it becomes invasive, that is, dangerous to humans. As soon as the invasive egg enters the human body (with food, through unwashed hands, contaminated water, etc.), under the influence of the chemical environment of the human gastrointestinal tract, the egg shells dissolve and the larva enters the intestines, its favorite habitat. Sometimes the microscopic larva does not remain in the intestine, but migrates through the circulatory system. It is not uncommon for roundworms to be found in large quantities in the ventricle of a patient’s heart, in the alveoli, bronchi and trachea, in the liver and even in the brain. Since the human roundworm, like all nematodes, does not have an intermediate host, the development of the larvae occurs directly in the external environment. All she needs is access to oxygen, sufficient humidity and a temperature close to room temperature.

Pinworm Female pinworm. 1 mouth; 2 esophagus; 36 parts of the reproductive system; 7 anal hole. Pinworm: adult and eggs

At the anterior end of the body of pinworms there is a swelling that surrounds the mouth opening and is called a “vesicle”.

Enterobiasis

Life cycle of pinworm

Whipworm and female whipworm; b male whipworm; 1 front end of the body; 2 rear end. adults and egg

Whipworm.

Whipworm development cycle

Trichinella A) female B) male Trichinella larva encapsulated in muscle fiber

Trichinella

Trichinella.

Trichinella. Trichinella larvae in muscle cells.

Life cycle of Trichinella

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