Medical leech type. The external and internal structure of the leech. The internal structure of a leech

Names: medicinal leech, common leech.

Area: Central and Southern Europe, Asia Minor.

Description: medicinal leech - a ringed worm of the class of leeches. Respiration is cutaneous, gills are absent. The muscles are well developed (about 65% of the body volume). The outer integument is called the skin, which consists of a single layer of signet-shaped cells that form the epidermis. Outside, the epidermal layer is covered with a cuticle. The cuticle is transparent, has a protective function and continuously grows, being periodically updated during the molting process. Shedding occurs every 2-3 days. The shed skin resembles white flakes or small white sheaths. The body of the leech is elongated, but not whip-like, and consists of 102 rings. On the dorsal side, the rings are covered with many small papillae. On the ventral side, the papillae are much smaller and less visible. The head end is narrower than the rear end. There are special suction cups at both ends of the body. The anterior sucker surrounding the oral opening is the sosal circle. It is triangular in shape with three strong jaws, each of which has up to 60-90 chitinous teeth arranged in the form of a semicircular saw. There is an anal opening (powder) near the posterior sucker. There are ten small eyes on the head of the leech, located in a semicircle: six in front and four on the back of the head. With their help, a medical leech saws through the skin to a depth of one and a half millimeters. At the edges of the jaws, the ducts of the salivary glands open. Saliva contains hirudin, which prevents blood clotting. There are no kidneys. Two genital openings are located on the ventral side of the body, closer to the head end.

Color: medical leech is black, dark gray, dark green, green, red-brown. On the back there are stripes - red, light brown, yellow or black. The sides are green with a yellow or olive tint. The belly is motley: yellow or dark green with black spots.

The size: length 3-13 cm, body width up to 1 cm.

Lifespan: up to 20 years old.

Habitat: fresh water bodies (ponds, lakes, quiet rivers) and damp places near water (clay, damp moss). Leeches love clean, running water.

Enemies: fish, desman.

Food/food: the medical leech feeds on the blood of mammals (humans and animals) and amphibians (including frogs), however, in the absence of animals, it eats the mucus of aquatic plants, ciliates, mollusks, insect larvae living in the water. It gently bites through the skin and sucks out a small amount blood (up to 10-15 ml). It can live for more than a year without food.

Behavior: if the reservoir dries up, the leech burrows into the moist soil, where it waits out the drought. In winter, it hibernates, hiding in the soil until spring. Does not withstand freezing soil. The characteristic posture of a hungry leech is that, having stuck its back sucker to a stone or plant, it stretches the body forward, making circular movements with its free end. Responds quickly to many irritants: splash, temperature and smell. When swimming, the leech strongly stretches and flattens, acquiring a ribbon-like shape and curving in waves. The rear sucker in this case performs the function of a fin.

Reproduction: hermaphrodite. After fertilization, the leech crawls ashore, digs a small depression in the moist soil, in which it makes a foamy mass from the secretion of the oral glands. It lays 10-30 eggs in this depression, after which it returns to the water.

Season/breeding period: June August.

Puberty: 2-3 years.

Incubation: 2 months.

Offspring: newborn leeches are transparent, similar to adults. They spend some time inside their cocoons, feeding on nutrient fluid. Later, they crawl into the water. Before reaching puberty, young leeches feed on the blood of tadpoles, small fish, earthworms or snails. If after three years the leech never drinks the blood of mammals, then it will never reach puberty.

Benefit / harm to humans: The first information about the use of leeches for medical purposes dates back to Ancient Egypt. The medical leech is used for bloodletting for medicinal purposes. In modern medicine, leeches are used to treat thrombophlebitis, hypertension, pre-stroke conditions, etc. Leech saliva that enters the human body has healing unique properties - it contains more than 60 biologically active substances.

Literature:
1. Great Soviet Encyclopedia
2. Vladislav Sosnovsky. Magazine "In the world of animals" 4/2000
3. Yan Zhabinsky. "From Animal Life"
4. D.G. Zharov. "Secrets of hirudotherapy"
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leeches(lat. Hirudinea) - a subclass of annelids from the class of belt worms (Clitellata). Most representatives live in fresh water. Some species have mastered terrestrial and marine biotopes. About 500 species of leeches are known, 62 species are found in Russia. The Russian word "leech" goes back to the Proto-Slavic *pjavka (cf. Czech. pijavka, Polish. pijawka), formed from the verb *pjati, a multiple form verb from *piti "drink".

general information

Leeches can move both in water and on land using the contraction of the muscles of the body. In water, it swims, making wave-like movements, on land it moves with the help of suction cups and crawling, like other worms. Both suction cups are used to move along the substrate and attach to it. Due to the strong muscular body, active leeches can, freely held by the posterior sucker, lift the body and make prowl searching movements with the anterior end of the body. During the rest, it prefers to climb under stones, snags and lie, partially leaning out of the water.

Leeches are able to respond to light, as well as to temperature, humidity and water fluctuations. They have a reflex reaction to the shadow, which may indicate the approach of potential food. The sensitivity of leeches decreases sharply during sucking and mating, to the point that when the posterior end of the body is cut off, the leech does not show a reaction and continues its behavior.

Nutrition

On average, a hungry leech weighing 1.5–2 g is capable of sucking up to 15 ml of blood at a time, while increasing by 7–9 times in mass.

Under natural conditions, hungry leeches wait for their prey, attaching to plants or other substrate with both suckers. When signs of an approaching victim appear (ripples, shadows, water vibrations), they unhook and swim in a straight line towards the source of vibrations. Having found an object, the leech fixes on it with its back sucker, while the front one makes prowl movements in search of a suitable bite site. Usually this is the place with the thinnest skin and superficial vessels.

The duration of bloodsucking varies depending on the activity of the leech, the properties of the blood of the animal and other conditions. On average, a leech that has been starving for 6 months is saturated in 40 minutes - 1.5 hours.

Reproduction and development

Wild leeches reach puberty in 3–4 years, feeding up to this age only 5–6 times. In captivity, maturation occurs faster, in 1–2 years.

Reproduction occurs once a year during the summer period from June to August. Copulation takes place on land, two leeches wrap around each other and stick together. Despite the fact that leeches are hermaphrodites, and cross-fertilization is possible, each individual, as a rule, acts in only one capacity. Fertilization is internal, immediately after it, leeches look for a place on the shore near the coastline to lay a cocoon.

Leech cocoon

One leech can lay up to 4-5 cocoons, they are oval in shape and covered with a spongy shell on the outside. Inside the cocoon there is a protein mass for feeding embryos, the number of which can be up to 20-30, their development to hatching takes 2-4 weeks. The hatched little leeches are miniature copies of adults and are ready to feed on blood. They feed mainly on frogs, as they cannot yet bite through the skin of mammals.

The history of the use of leeches in medicine

Hirudotherapy(lat. hirūdō - "leech", other Greek. θεραπεία - "treatment") - a method of alternative medicine, one of the areas of naturopathy, the treatment of various human diseases using a medical leech. Leech therapy was previously used in conventional medicine, but fell into disuse in the 20th century due to the advent of synthetic anticoagulants, including hirudin.

Hiruda, a medicinal leech native to Europe, has been used for bloodletting for hundreds of years. Hippocrates, Galen, Avicenna wrote about the treatment with leeches. On the walls of Egyptian tombs, drawings of the use of leeches were found. The medicinal properties of the medicinal leech have been known to people for thousands of years. A description of the methods of treating various diseases with the help of a leech can be found in the medical collections of most ancient civilizations: Ancient Egypt, India, Greece. The use of leeches was described by Hippocrates (4th-5th centuries BC) and Avicenna (Ibn Sina, 980-1037).

Medicinal leeches were most widely used in the 17th-18th centuries in Europe for bloodletting in connection with the concept of "bad blood", which then dominated medicine. In order to release bad blood, doctors sometimes put up to 40 leeches at the same time to one patient. Preference over vein bloodletting was given to them in case of need for bloodletting from hard-to-reach or tender places (for example, gums). In the period from 1829 to 1836, 33 million leeches per year were used in France for the treatment, in London - up to 7 million with a population of 2.3 million inhabitants. Russia supplied Europe with about 70 million leeches a year. After a paradigm shift in the middle of the 19th century, bloodletting was abandoned, and the use of leeches in Europe practically ceased.

Scientific studies of the mechanisms of action of leeches on humans began at the end of the 19th - beginning of the 20th century with the work of John Haycraft, who discovered the anticoagulant effect of leech extract. In 1884, he discovered an enzyme from the saliva of a leech - hirudin, and in 1902 preparations were obtained from hirudin. These studies marked the beginning of the scientific use of leeches in medicine. In our time, treatment with the help of medicinal leeches is experiencing a rebirth.

Features of the therapeutic effect

Live leeches are attached directly to the human body according to specially designed schemes. The choice of the place of attachment is determined by many factors: the disease, the severity of the process, the condition of the patient. The sucking process lasts from 10–15 minutes to an hour, after which the leeches are removed with alcohol, iodine, or, if fed to the full, they are released on their own. Well-fed leeches must be destroyed by placing them in a solution of chloramine, their reuse is not allowed. The therapeutic effect of exposure to live leeches is due to several factors:

• Dosed bloodletting (from 5 to 15 ml of blood for each leech, depending on the mass of the leech and the duration of the attachment). It is used to treat arterial hypertension, glaucoma, congestion in the liver, general intoxication of the body.
• The action of biologically active substances in leech saliva, the main of which is the anticoagulant hirudin, which reduces blood clotting. Used to treat angina and myocardial infarction, thrombophlebitis, vein thrombosis, hemorrhoids.
• A complex of body responses to a bite, biologically active substances of leech saliva and subsequent blood loss.

A reliable guarantee of protection against the transfer of infectious agents by a leech is the use of animals grown under artificial conditions and starving for a sufficient time, in the intestines of which there is no pathogenic flora. The use of leeches in therapy was revived in the 1970s: in microsurgery, they are used to stimulate blood circulation in order to save grafted skin and other tissues from postoperative venous stasis.

Other clinical uses for medicinal leeches include the treatment of varicose veins, muscle spasms, thrombophlebitis, and arthrosis. The therapeutic effect comes not only from the flow of blood through the tissues while feeding on leeches, but from further and steady bleeding from the wound left after the detachment of the leeches. The saliva of leeches has analgesic, anti-inflammatory and vasodilating properties.

What leeches can treat?

Of several dozen types of medicinal, there are only three:

• pharmacy;
• medical;
• eastern.

We hasten to upset lovers of self-treatment with leeches. Caught in a local reservoir, at best they will be useless, at worst they will bring irreparable harm, rewarding a person with a number of unpleasant diseases that they can carry. Leeches intended for hirudotherapy are grown in the complete sterility of special laboratories and are used only once.

Indications for use

There are a number of diseases in which treatment with leeches significantly improves the patient's condition:

• Problems with blood vessels, blood formation, tendency to form blood clots, blood stasis.
• Diseases of connective tissues and joints.
• Violation of the functions of the genitourinary system.
• Diseases of a neurological nature.
• Menstrual disorders, inflammation of the genital organs, ovarian dysfunction, endometriosis.
• Neurosis, epilepsy, migraine, sleep disorders.
• diseases associated with disorders of the thyroid gland.

The benefits of leeches in the treatment of blood vessels and blood

With varicose veins, treatment with leeches stimulates blood formation, helps to strengthen the walls of blood vessels. Hirudin, secreted by a leech with saliva, is a natural biologically active substance that improves metabolism and prevents the formation of blood clots. In the early stages of the disease, it is possible to completely cure or stop its development with the help of hirudotherapy.

Treatment for arthrosis and osteochondrosis

Non-inflammatory lesions of the joints and cartilaginous tissues, caused by circulatory or metabolic disorders, large or improperly distributed loads, injuries, are successfully treated with leeches. Treatment is aimed at reducing pain, increasing the motor work of the joints and stopping the progression. The secret secreted by leeches when bitten contains a natural analgesic enzyme that improves the patient's condition. No wonder a couple of centuries ago, military doctors put soldiers of these bloodsuckers in the wound area to prevent pain shock.

Treatment of diseases of the spine

Hirudotherapy plays an important role in the complex treatment of spinal ailments. It contributes to the restoration of normal physiological processes occurring in the deep tissues surrounding the spinal column. As an effective remedy that complements the main one, treatment with leeches for spinal hernia is used. In the absence of the desired result from conservative treatment, one has to resort to surgical intervention. During the period of postoperative rehabilitation, leeches can bring a lot of benefits to the patient. Their use helps to prevent postoperative complications. Thanks to hirudotherapy sessions, cicatricial adhesions in ligaments and tendons are reduced, the likelihood of new hernias is reduced due to the redistribution of loads, congestion in the vertebral veins disappears.

Treatment with leeches is also effective in osteochondrosis. The cause of this pathology is degeneration of the intervertebral discs, ligaments that lose water, become thinner, covered with microcracks. As a result, the distance between the vertebrae decreases, there is pressure on the nerve roots, causing them to be pinched, spasms and inflammation in the paravertebral muscles.

The benefits of leeches for weight loss

Medical leeches are actively used in aesthetic medicine for weight loss and cellulite treatment. This effect occurs due to the influence of substances in the saliva of annelids on metabolism and blood circulation. Biologically active substances of leeches have a lipolytic effect - they burn fat. In addition, the process of microcirculation is being established and the supply of cells with oxygen is enhanced, the stagnation of lymphatic fluid in adipose tissue is eliminated. All this contributes to the reverse development of pathological changes in cellulite and a decrease in body volume.

The effect after using leeches for weight loss will be even more noticeable if you combine hirudotherapy with a balanced diet and regular exercise.

Acne treatment with leeches

Acne treatment with medicinal leeches is very effective. Already after several sessions of putting leeches on the face, the rash is significantly reduced, and after the entire course it completely disappears. The result of such treatment lies in the amazing and varied properties of these animals on the skin.

First of all, saliva of leeches has a powerful bacteriological and antiseptic effect. It destroys all pathological pyogenic microorganisms, which cause the formation of acne. Secondly, substances that leeches transmit with a bite have a pronounced anti-inflammatory effect, due to which the inflamed areas heal quickly. Thirdly, due to the mechanical and biological action of animals, the blood supply to the skin increases, which plays an important role in establishing the normal functioning of the sebaceous glands.

As you can see, hirudotherapy in cosmetology has a wide range of applications. Do not refuse such treatment just because you are disgusted with leeches. You just have to be patient a little and, perhaps, you will get rid of the cosmetic problem that has tormented you for many years forever.

Contraindications

Contraindications are:

• diseases accompanied by bleeding due to reduced blood clotting;
• hemolysis;
• anemia (anemia);
• weakening or exhaustion of the body;
• intolerance to the body of leech enzymes (allergic reactions);
• tuberculosis of various localizations;
• oncological diseases.

Harm of leeches

Due to its specific structure and diet, the use of leeches for medicinal purposes may be associated with the following risks:

• The digestive tract of the medicinal leech constantly contains the bacterium Aeromonas hydrophila, which protects it from infections when it feeds on the blood of sick animals and contributes to the proper absorption of nutrients. In humans, it can cause gastrointestinal disorders, poisoning, and even diseases of the mucous membranes. Although hirudotherapists deny the possibility of bacteria getting into the jaws of leeches, this hypothesis has not been definitively refuted.
• With the blood of infected animals, pathogens of various dangerous diseases enter the body of a leech. Settling on the jaws, they can be transmitted by bite to other people and animals. The use of leeches grown in artificial conditions made it possible to get rid of this problem.
• Leech saliva contains substances that thin the blood, and after removing it, the wound can bleed for a long time. In addition, in some cases, these substances can severely irritate the skin.

The process of breeding leeches is simple and accessible to anyone. In order to organize a leech farm, you need to find a room with several rooms, since leeches at various stages of their growth: cocoon, fry, adult, should be kept separately. As an option, you can adapt one room by dividing it into sectors. The main condition for breeding leeches is to maintain a favorable microclimate for them: the air temperature is from 25 to 27º C.

Although wild leeches in their natural environment live in colder waters, the reproduction and development of their medical relatives in the heat is much better. The temperature of the water in which the leeches are located should be at room temperature, that is, the same 25-27º C. The air humidity in the room should be at least 80%.

Containers for leeches are ordinary 3-liter jars filled with water purified through special filters. Aquariums can also work, but it will be much more expensive. It is necessary to carefully monitor all stages of the growth of leeches and “transfer” animals to other premises (sectors) in time when they reach the next “age”.

By the way, all work on feeding leeches, purifying water in containers, transplanting leeches, etc., is carried out only manually. Even on large leech farms. Leeches feed on blood, which can be obtained from livestock farms, from private farmers, at a slaughterhouse, having concluded appropriate agreements with them.

Breeding leeches on an industrial scale is carried out by special biofactories. Currently, there are only four such factories in Russia: two in the Moscow region, one in St. Petersburg and one in Balakovo, Saratov region. In total, they grow 5-5.5 million leeches per year, which makes Russia the world leader in the production of leeches in the world: only 0.5 million per year are grown in France and the United States.

A leech is a worm that has a kind of "brain". Nietzsche's Zarathustra tried to assert that he was familiar with the mental, or rather mental, activity of the leeches of these interesting worms. Researchers, of course, have not yet found the “brain” of leeches, but it is quite possible to assert that the leech has a fairly branched nervous system, consisting of a peripheral section and a sympathetic autonomic system.

There is an opinion that a leech "loves" a person. Researchers of this "crawling world" have long wondered if any senses are possible in leeches or any other worms. Well, animals, of course, cannot love like people. But some species of mammals are characterized by certain emotional experiences associated with devotion, friendliness, affection.

Sources

https://ru.wikipedia.org/wiki/Leechs http://www.pijavki.com/o_pijavkah.html http://polzovred.ru/zdorovie/piyavki.html#i-2 http://pomogispine.com /lechenie/girudoterapiya.html http://www.aif.ru/health/life/1188201

The leech has many amazing qualities. It's hard to imagine, but this little worm has a sense of smell, taste and touch, and also distinguishes between heat and light.

The leech is hermaphrodite by nature, that is, it has the characteristics of both sexes. When they meet, the leeches fertilize each other.

The leech lives only in fresh water. It can be found in large quantities in the waters of Central and Southern Europe and Asia Minor. Under natural conditions, leeches feed on the blood of animals that come to drink.

Not every leech can heal a person. Of the more than 400 species of leeches found in nature, only one species is used in medical practice. This is a medical leech. This species has two subspecies - pharmaceutical (Hirudina officinalis) and medicinal (Hirudina medicinalis) leeches. Both subspecies are used for medicinal purposes. In order to understand this issue and distinguish a useful leech from the rest, it is absolutely not necessary to know the characteristics of these animals, and even more so to go to reservoirs with a net. Medicinal leeches must be purchased only in pharmacies, in addition, they must be licensed, like any medicine.

Leeches, which are used for medicinal purposes, have not been caught in swamps and ponds for a long time. They are grown in special biofactories under artificial conditions under the careful supervision of biologists. This is necessary so that the leeches are sterile and cannot become a source of infection for the people who use them.

medical leech

A medical leech is a special, thoroughbred leech, which differs sharply from the pond one. It is grown precisely in order to serve a person only once. The leech is used as a disposable syringe, which is absolutely sterile. After the procedure, the leech is killed. It is believed that now she can be potentially dangerous, as she dealt with a sick person, which means sick blood. Sterilizing a leech is a very troublesome business.

However, there is one circumstance in defense of the leech. Her saliva contains the strongest bactericidal substance that kills microbes contained in the blood. Therefore, the leech disinfects its food and cannot itself be a source of infection. But you cannot be sure that this substance will cope with any bacteria that can enter the body of a leech, for example, with the blood of infected animals (if it is a pond leech). This is why it is easier to grow a new sterile leech than to risk using an old one. For such economic benefits and our health, this blood-sucking creature pays with its life.

The most valuable thing in a medical leech is its secret, which is excreted with saliva. Leech saliva contains more than a hundred biologically active substances containing the entire periodic table. Therefore, the impact of a leech on a person can replace any medicine prepared chemically and therefore having a lot of side effects. In the process of treatment with leeches, all biologically active substances enter the bloodstream and have a beneficial effect on our organs, systems and well-being. At the same time, the leech secret is completely harmless, because it is used in minimal doses and strictly as needed.

The nature of the action of this healer - leeches - is unique. Medical beer is a very sensitive organism. It recognizes a diseased organ in a special way and unmistakably finds biologically active points corresponding to this organ. Therefore, leeches are not only a therapeutic, but also a diagnostic tool. Many doctors allow leeches to determine the sites of bites themselves, checking their diagnosis against them with the “diagnosis of a leech”. That is why hirudotherapy is successfully used in any field of medicine for a wide range of diseases.

Another interesting characteristic feature of the leech is its cleanliness. The human body must be very clean and without foreign odors, only then the leech will stick to it.

Interestingly, the leech is very sensitive to the bad habits of humans. She will never treat a drunk patient, she ignores a heavy smoker who smells of tobacco. And if the patient has not washed for a long time, the leech will immediately crawl away, no matter how hungry she may be. These natural healers are very picky!

The structure of a leech

The leech is an annelids averaging 12 to 15 cm in length. It has a greenish back with orange stripes and black dots. The medicinal leech lives in fresh water bodies of Central and Southern Europe and Asia Minor. It feeds on the blood of large mammals entering the water during a watering place.

The leech is a digestive tube covered with sensitive skin. The leech breathes through the skin, and the skin protects it from external irritants. The skin performs another function - it is the sensory organ of the leech. The leech has a very developed muscular system, which consists of ring muscles that cover the entire body of the leech and form its suckers, longitudinal muscles that stretch along the body, and dorsal-abdominal muscles located from the back to the abdomen. This structure of the muscular system allows the leech to be very mobile, to make the most diverse and fast movements.

On the head of a medicinal leech there are five pairs of eyes, and in the mouth there are three jaws with chitinous teeth, of which there are about 260 pieces. With their help, the leech cuts through the skin to a depth of 1.5-2 mm and sucks up blood in a volume of 5-15 ml, the same amount flows out of the bite site over the next 3-24 hours. This is due to the fact that the secret of leech saliva envelops the walls of the affected vessels, as a result, the blood loses its ability to coagulate. But such bleeding is absolutely harmless to human health and is easily tolerated by the patient. 5-7 individuals are usually attached to the session. Even one session of hirudotherapy is very healing, as a whole complex of biologically active substances and enzymes enters the human blood, which cause anti-inflammatory, analgesic, decongestant effects, reduce the likelihood of blood clots, improve blood microcirculation, and also activate the human immune system.

The oral cavity of the leech passes into the pharynx, which has thick muscular walls, they act as a pump when pumping out blood.

The stomach of a leech is a gut with 10 pairs of lateral processes. In length, the stomach occupies 2/3 of the body length of the leech and can hold from 5 to 15 ml of blood. And what is especially important: the intestines of the leech contain special bacteria that disinfect harmful substances, so the saliva of the leech is always sterile. Therefore, the medical leech is actively used for thrombophlebitis, hypertension, in pre-stroke states and other diseases. Due to the fact that the leech stimulates blood circulation in tissues, affects the walls of blood vessels and increases blood oxygen saturation, it has a beneficial effect on the entire body as a whole.

How to distinguish a real medical leech from a fake one?

They are not medical: leeches are one-colored, without stripes on the back. In addition, take a close look at the shape and other external signs of the leech. It should not be covered with hairs, have a cylindrical body and a blunt head. A real medical leech is smooth, almost flat, with a sharp head.

The healing effect of leeches

The mechanism of the therapeutic effect of leeches is very multifaceted, so the effect itself occurs in a complex. Bloodletting gives a kind of impetus to the immune system of the body. Thanks to this, there is an influx of "fresh" blood and renewal of the whole organism, in which the healing processes are launched. In addition, a small loss of blood lowers blood pressure. A special substance hirudin, which prevents blood clotting, stimulates the blood supply to all organs. But this is not all the functions of leech saliva. Consider each type of therapeutic effect of a leech in detail.

So, the therapeutic effect of hirudotherapy consists of several factors: reflex, mechanical and biological.

reflex action

This action lies in the fact that the leech bites through the skin only at biologically active points, which are also called acupuncture points. These points are used in acupuncture. They are inextricably linked with all organs and systems. By acting on certain points, the doctor starts the process of self-healing of the organ, enhancing its energy. The mechanism of the reflex action of leeches is exactly the same as with acupuncture. In addition, the leeches themselves feel the points that need to be acted upon, that is, they choose the bite sites. Thanks to this, even a person who does not know acupuncture can put leeches. But it is better, of course, if this medical manipulation is carried out by a doctor.

mechanical action

It consists in the fact that after a leech bite, lymph continues to ooze with an admixture of capillary blood under the influence of hirudin and destabilase injected with saliva. Due to the long expiration of lymph (from 5 to 24 hours), mechanical irritation of the lymph nodes occurs and the production of natural protective cells - lymphocytes - is stimulated. This leads to an increase in local and general immunity. In addition, local blood flow is unloaded, which contributes to blood renewal and greater blood flow to the diseased organ.

Biological action

This is the most valuable and most important effect, which is provided by the leech saliva itself, which contains a huge amount of useful substances. The most valuable of them are: hirudin, destabilase complex, bdellins, eglins, hyaluronidase, antibacterial and analgesic substances.

Hirudin- the most studied leech hormone. It slows down blood clotting and flushes blood clots from blood vessels, preventing thrombosis. Hirudin is the best remedy in the treatment and prevention of intravascular coagulation syndrome.

Hyaluronidase- an enzyme that is found in the venoms of snakes, spiders, extracts of human testes and some bacteria. This substance is necessary for the fertilization process, so hirudotherapy successfully copes with such a problem as infertility.

Bdellins trypsin and plasmin inhibitors.

Eglins- substances that the body needs, suffering from rheumatoid arthritis, gout, emphysema. Eglins act in such a way that they prevent further damage to the joints and lungs, curing an existing pathology. Eglins penetrate into the blood and, connecting with other components, prevent the process of tissue degradation. This property allows the use of leeches in the treatment of skin diseases and injuries, surgical treatment.

In addition to the secretion of saliva, the symbiont bacterium Aeromonas hydrophilia contained in the intestinal canal of the medical leech, which provides a bacteriostatic effect, has a healing effect.

So, we list all types of therapeutic effects of leeches on the human body:

Anticoagulant;

thrombolytic;

Anti-ischemic;

Antihypoxic;

Hypotensive (more precisely, normotensive);

Decongestant;

Draining;

Restoration of microcirculation;

Lipolytic;

Restoration of neuromuscular transmission of impulses;

General reflex;

Restoration of the permeability of the vascular wall;

Bacteriostatic;

Immunostimulating;

Analgesic.

A leech bite is often much more effective than a drug injection. The fact is that when the drug is injected, the medicinal substances are distributed evenly throughout the body, and the leech acts only on the diseased organ. In the zone of influence is 70-80% of all biologically active substances introduced by the leech into the patient's blood.

Hirudotherapy session lasts from 40 minutes to one hour. Leeches should not be removed, they themselves determine the end of the session. Depending on the complexity of the disease, treatment requires 5 to 10 sessions 1-3 times a week.

Hirudotherapy can be used as an independent method of treatment, and can be combined with other methods of naturopathy, most often with herbal medicine, as well as with homeopathy and physiotherapy. This combination is determined by the doctor, depending on the nature of the disease, the patient's condition and the characteristics of his body.

How a leech "works"

With the help of sharp jaws, the leech bites through the skin to a depth of 1.5-2 mm and sucks blood in a volume of 5-15 ml. The same amount of blood flows from the bite site subsequently (over the next 3-24 hours). This is because leech saliva contains hirudin, which prevents blood clotting. You don't need to stop the bleeding. In one treatment session, usually 5 to 7 leeches are applied.

The medical leech itself chooses the bite site - the warmest area, the richest in blood. Here it reveals biologically active points through which it acts on blood vessels and internal organs and systems of a person.

Gradually, as it becomes saturated, the leech noticeably increases in size. The volume of blood that she drinks is 3-5 times her own weight, that is, it can be up to 15 ml. Feeding on blood, the leech injects into the bite site, that is, into the bloodstream of the vessel, its healing saliva - a unique balanced complex of biologically active substances. Almost immediately after a leech bite, its therapeutic effect begins. Valuable substances of saliva under the influence of its special enzymes quickly penetrate into the tissues. And already 20 minutes after the removal of the leech, the components of its secret are carried with the bloodstream throughout the body.

A leech bite resembles a mosquito bite or a nettle sting. Then there is a purely mechanical unloading of the blood flow, that is, a person practically does not feel how the leech sucks blood. The blood itself flows to her mouth and stomach. Having sated, the leech itself disappears, and the blood (mainly lymph) continues to flow out in a very thin stream. For a period of 3 to 24 hours, it can flow out as much as the leech drank, that is, about 12-15 ml. And in total, a person loses no more than 30 ml of capillary blood along with lymph from one leech. This process is also healing, so you can not stop it. Such a small loss of blood triggers the mechanism of stimulation of the immune system and eliminates swelling.

The probability of infection of people through leeches during hirudotherapy sessions is practically excluded. Leeches are bred in special biofactories by the canning method, they are kept in sterile conditions. Leeches feed on the tested blood of animals. Ready-to-sell leeches are tested and certified. After treatment, leeches are destroyed and not reused.

Independent use of leeches

You can choose different ways to treat the disease: drink pills, be treated with herbs, use physiotherapy or turn to hirudotherapy. Each method has its pros and cons. But treatment with leeches stands out from the general list of treatment methods in that there are much more pluses than minuses. And the cons themselves are only in the presence of a small number of contraindications, which are quite rare. Therefore, there are more and more adherents of hirudotherapy today. A serious problem is the choice of a qualified hirudotherapist - such specialists can only be found in large cities, in large clinics or specialized hospitals. Leeches are much easier to acquire.

The doctor using this method must know the human anatomy perfectly, find an individual approach to each patient, taking into account his diseases, physical and mental condition. It is the doctor who determines how many sessions the patient will need and how many leeches to put during each session.

However, the procedure for installing a leech is quite simple, so you can use leeches on your own, but subject to certain conditions.

Firstly, before self-treatment with leeches, you should still consult a specialist. Remember the contraindications to hirudotherapy: although there are few of them, they are very serious. In addition, it is necessary to agree on the number of leeches and procedures. And remember that everything is in moderation. Your well-being will tell you when to stop the procedures, which should be no more than ten.

Secondly, only an experienced specialist should install leeches on the mucous membranes and genitals - it is extremely dangerous to do it yourself!

Thirdly, you can put leeches on diseased organs only if you know exactly your diagnosis and the location of the diseased organ. You can go the other way: put the leech on its back and give it the right to choose the right point on its own. Be sure - the leech will not be mistaken.

Since the leech is a living being, it has its own characteristics. A leech may refuse to treat you, that is, to stick, if there is a change of weather on this day, magnetic storms or other jumps in biorhythms, to which leeches are very sensitive. In addition, leeches do not like to eat at night, so hirudotherapy sessions are held only in the morning and afternoon, at least not late in the evening.

How to put a leech at home

So, you bought leeches in a pharmacy. They should be stored in a jar of tap water, the neck of which is covered with gauze, in a bright place at a temperature of 10–15 °C. Water should be changed daily. Only healthy and hungry leeches, moving quickly in water, are suitable for treatment. Sluggish, with nodules, with a sticky surface, leeches are not suitable for consumption.

Leeches can "work" only once. After using the leech, it is thrown away. Usually put five leeches, at an advanced stage of the disease, you can put seven leeches. To enhance the effect of leeches put on acupuncture points used in reflexology. But if you have never encountered acupuncture, then you can arrange the leeches arbitrarily - they themselves will choose the places of the strongest impact on the body.

They put leeches on the heart area (to cleanse blood vessels), the liver (to cleanse the liver), on the limbs (for thrombophlebitis and varicose veins), behind the ears (for atherosclerosis and heart failure), on the back of the head (for hypertension and for general cleansing of blood vessels), on back (for general cleansing of blood vessels). You can not put leeches on those places where there are distracting veins (eyelids, temples, scrotum).

Do not be afraid of the sensations that may arise during the suction of a leech - this is normal. You may feel a slight burning sensation, like an ant sting, and even severe itching, especially if the leech is placed in a place where the skin is thin. These discomforts pass in a couple of minutes. After a skin puncture, a characteristic trace of small leech teeth remains on it.

In the first ten minutes, the leech lets its saliva into the wound, containing about one hundred and fifty healing substances. At this time, the blood becomes homogeneous, that is, homogeneous, due to the dissolution of small cholesterol plaques and blood clots. Then the leech begins to suck blood, continuing to secrete saliva, but in smaller quantities.

One leech sucks up to 5-10 ml of blood. When the leech fills its stomach, it will fall off on its own. But with incomplete exposure, it is carefully removed.

Rules for setting leeches

Before setting up leeches, you need to stock up on the following supplies:

Healthy, mobile leeches;

Bank with clean water;

Beaker or test tube;

Sterile tray with sterile dressing material;

A bottle of hydrogen peroxide;

Ampoule with glucose or sweetened water;

A jar of salt water to place the leech after removal.

This procedure is best done with an assistant. If you put leeches on another person, do it in this order.

1. Lay the person comfortably on a bed or sofa.

2. Expose the part of the body where the leeches should be placed. If there is hair, it must be shaved off.

3. Rinse the skin well with warm water and dry it dry.

4. Moisten the skin with sweet water or glucose for a better suction of the leech.

5. Grab the tail end of the leech with tweezers and place it in a test tube.

6. Attach the tube to the desired location on the skin.

7. Wait for the leech to suck on. Having sucked, it will fall off the skin itself.

8. Remove the leech and place it in a jar of salted water, then flush it down the drain.

9. Apply a sterile napkin to the places where the leeches are sucked. After the procedure, microbleeding is possible for 6-24 hours, so a volume bandage is necessary, which should be removed only the next day.

10. In the presence of severe bleeding, a pressure bandage should be applied to the wounds.

11. If you need to remove the leech earlier, then the skin under it is moistened with salted water.

12. Leeches can only be used once!

It is necessary to monitor the well-being of a person during the setting of leeches and for some time after the end of the procedure. It is strictly forbidden to tear off a leech by force, as it can cause significant bleeding.

You can re-put leeches only after 5-6 days.

Warning!

After the procedure, itching around the wound may appear at the places where leeches are placed. It is necessary to lubricate the skin around the wound with a mixture of ammonia and vaseline oil in equal amounts. The itch will pass.

Acquisition and storage of leeches

Leeches should be purchased only in specialty stores and pharmacies. They sell certified medical leeches grown in biofactories. These leeches are under control from the moment of their birth, so they are a guarantee of effective and safe treatment. In no case should wild leeches be used, because it is impossible to know what the leech fed on and what infections it is a source of. Despite the fact that the leech has a unique set of disinfectants, it cannot be tested for the entire range of infections found in the world. Therefore, one should not take risks, especially since buying a leech is not a problem today.

Leeches are sold in glass jars with clean water in which they live. Such water must be maintained constantly. Water should be well settled and at room temperature, and the jar itself should be in a room with an air temperature of +8 to +20 ° C. Sudden changes in air or water temperature are detrimental to leeches. They do not like leeches and strong odors; upon contact with odorous substances, they get sick and die. They can go without food for half a year, so all this time you only need to change the water and feed the leeches with sugar syrup, which they love very much.

When purchasing leeches, monitor their condition. A healthy leech is active: it swims, resists when it is touched or tried to be placed in a bubble. Watching leeches is extremely interesting, because they are living barometers. In clear weather, leeches crawl out onto the walls of the jar in which they live, and in bad weather they stay under water.

pijawka) formed from the verb *pjati, multiple verb from *piti"drink". At the same time, in Russian the form would be expected *leech(cf. Ukrainian p᾽yavka), and and in this case, they explain it by a secondary rapprochement with the verb "drink" according to folk etymology.

In Latin hirūdō find the same suffix as in testūdō"tortoise", however, the etymologization of the root causes difficulties. As possible relatives are called hīra"small intestine" and haruspex"haruspex".

Structure

The body length of different representatives varies from a few millimeters to tens of centimeters. The largest representative Haementeria ghilianii(up to 45 cm).

The anterior and posterior ends of the body of leeches bear suckers. At the bottom of the anterior there is a mouth opening leading to the pharynx. Proboscis leeches (detachment Rhynchobdellida) the pharynx is able to move outward. In jaw leeches (for example, medicinal leeches), the oral cavity is armed with three movable chitinous jaws that serve to cut through the skin.

Nutrition

Biology of the body

The body is elongated or oval, more or less flattened in the dorsal-abdominal direction, clearly divided into small rings, which in number 3-5 correspond to one segment of the body; numerous glands in the skin that secrete mucus; at the posterior end of the body there is usually a large sucker, often at the anterior end there is a well-developed sucker, in the center of which the mouth is placed; more often, the mouth is used for suction. At the anterior end of the body there are 1-5 pairs of eyes arranged in an arc or in pairs one after another. Powder on the dorsal side above the rear suction cup. The nervous system consists of a two-lobed supraesophageal ganglion, or brain, connected to it by short commissures of the subpharyngeal ganglion (derived from several merged nodes of the abdominal chain) and the abdominal chain itself, located in the abdominal blood sinus and having about 20 nodes. The head node innervates the sense organs and the pharynx, and 2 pairs of nerves depart from each node of the abdominal chain, innervating the body segments corresponding to them; the lower wall of the intestine is equipped with a special longitudinal nerve that gives branches to the blind sacs of the intestine. The digestive organs begin with a mouth armed with either three chitinous toothed plates (maxillary P. - Gnathobdellidae), which serve to cut through the skin when sucking blood in animals, or a proboscis capable of protruding (in proboscis P. - Rhynchobdellidae); numerous salivary glands open into the oral cavity, sometimes releasing a poisonous secret; the pharynx, which plays the role of a pump during sucking, is followed by an extensive, highly extensible stomach, equipped with lateral sacs (up to 11 pairs), of which the posterior ones are the longest; the hindgut is thin and short. The circulatory system consists partly of real, pulsating vessels, partly of cavities - sinuses, representing the remainder of the cavity (secondary) of the body and interconnected by annular channels; blood in proboscis P. is colorless, in jawed - red due to hemoglobin dissolved in the lymph. Special respiratory organs are available only in the river. Branchellion, in the form of leaf-like appendages on the sides of the body. The excretory organs are arranged according to the type of metanephridia, or segmental organs of annelids, and most P. have a pair of them in each of the middle segments of the body. P. - hermaphrodites: the male genital organs consist of most of the vesicles (testes), a pair in 6-12 middle segments of the body, connected on each side of the body by a common excretory duct; these ducts open outwards with one opening lying on the ventral side of one of the anterior rings of the body; the female genital opening lies one segment behind the male and leads into two separate oviducts with saccular ovaries. Two individuals copulate, each simultaneously playing the role of a female and a male. P. during laying of eggs allocates with glands lying in the genital area, thick mucus surrounding the middle part of P.'s body in the form of a cover; eggs are laid in this sheath, after which P. crawls out of it, and the edges of its holes come together, stick together and thus form a capsule with eggs inside, usually attached to the lower surface of the algae leaf; the embryos, leaving the facial membrane, sometimes (Clepsine) keep for some time on the underside of the mother's body. All P. are predators, feeding on the blood of mostly warm-blooded animals or mollusks, worms, etc.; they live mainly in fresh water or in wet grass, but there are also marine forms (Pontobdella), just like terrestrial forms (in Ceylon). Hirudo medicinalis - medical P. up to 10 cm long and 2 cm wide, black-brown, black-green, with a longitudinal patterned reddish pattern on the back; the belly is light grey, with 5 pairs of eyes on the 3rd, 5th and 8th rings and strong jaws; distributed in the swamps of the South. Europe, South. Russia and the Caucasus. In Mexico, Haementaria officinalis is used in medicine; another species, H. mexicana, is poisonous; in tropical Asia, Hirudo ceylonica and other related species living in humid forests and in the grass are common, causing painful bleeding bites to humans and animals. Aulostomum gul o - horse P., black-green in color, with a lighter bottom, has a weaker armament of the mouth and therefore unsuitable for therapeutic purposes; the most common species in the north. and central Russia. Nephelis vulgaris is a small P. with a thin narrow body, gray in color, sometimes with a brown pattern on the back; equipped with 8 eyes located in an arc at the head end of the body; related to her original Archaeobdella Esmonti, pink, without posterior sucker; lives on the silt bottom in the Caspian and Azov seas. Clepsine tessel ata - Tatar P., with a wide oval body, greenish-brown in color, with several rows of warts on the back and 6 pairs of triangular eyes, located one after the other; lives in the Caucasus and Crimea, where it is used by the Tatars for medicinal purposes; the transitional place to the order of bristle-legged (Chaetopoda Oligochaeta) worms is occupied by Acanthobdella peledina, found in Lake Onega.

History of medical use

Medical leech ( Hirudo officinalis) - found in the north of Russia, so especially in the south, in the Caucasus and Transcaucasia, in Poti, Lankaran. In the 19th century, leeches were a profitable export item: Greeks, Turks, Italians, and others came to the Caucasus for them. In addition, artificial breeding of leeches was carried out in special pools or parks according to the Sale system in Moscow, St. Petersburg, Pyatigorsk and Nizhny Tagil. Based on the laws in force, catching leeches during their breeding season - in May, June and July - is prohibited; when fishing, only those suitable for medical use should be selected, that is, not less than 1 1/2 inches in length; leeches are small, as well as too thick, should be thrown back into the water when catching. To supervise the observance of these rules, the provincial medical departments are entrusted with the duty to testify the stocks of leeches from barbers and other merchants who trade them. Since medicine expelled leeches from use, the leech trade has fallen completely.

Notes

Sources

• Ruppert E.E., Fox R.S., Barnes R.D. Invertebrate zoology. Vol. 2: Lower coelomic animals. M., "Academy", 2008.

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See what "Leech" is in other dictionaries:

- (Hirudinea), a class of annelids. Length from several mm up to 15 cm, rarely more. Descended from small-bristle worms. The body is usually flattened, rarely cylindrical, with two suckers (oral and posterior); consists of a head blade, 33 rings ... ... Biological encyclopedic dictionary

Leeches, a class of worms. Length 0.5-20 cm. Body usually flattened, with 2 suckers. About 400 species live in fresh and marine waters. Most leeches are bloodsuckers, the salivary glands of which secrete the protein substance hirudin, which prevents ... ... Modern Encyclopedia

Class of annelids. Length 0.5-20 cm. They have front and back suction cups. 400 species. In fresh and marine waters. Most leeches are bloodsuckers whose salivary glands secrete hirudin, which prevents blood clotting. Medical leech ... ... Big Encyclopedic Dictionary

- (Hirudinei) detachment of the class of annelids. The body is elongated or oval, more or less flattened in the dorsal-abdominal direction, clearly divided into small rings, which in number 3 5 correspond to one segment of the body; Numerous glands in the skin... Encyclopedia of Brockhaus and Efron

External structure

Medical leech

The body of leeches is noticeably flattened in the dosoventral direction. At the anterior end there is a muscular anterior sucker, in the center, which fits the mouth opening. At the posterior end there is a second, very strongly developed posterior sucker, above which the anus opens on the dorsal side.

Leeches do not have any appendages or parapodia. The bristles are preserved only in a primitive species - the bristle leech. It has four pairs of setae on five anterior segments.

leeches very mobile, crawling and floating animals . Attached by the posterior oral sucker, the leech pulls the body forward, then attaches with the oral sucker, while the posterior sucker is pulled away from the substrate and the body is pulled to the head end, bending into a loop. Then the leech is sucked again by the back sucker, etc. Thus, the leeches make "walking" movements. Leeches swim, producing wave-like movements with their whole body, in which their body bends in a dorsoventral direction.

The external ringing of leeches is false, secondary, it does not coincide with the true internal segmentation. Each real segment in different leeches corresponds to 3 to 5 outer rings. The external ringing of leeches is an adaptive trait that provides body flexibility with a powerful development of the skin-muscle sac.

The body of leeches is formed by 33 segments (with the exception of the bristle leech, which has 30 segments), of which a weakly separated head lobe - the prostomium - and four head segments are part of the anterior sucker. The trunk section is represented by 22 segments. The posterior sucker is formed by the fusion of the last seven segments.

Skin-muscular sac

The skin-muscular sac of leeches is formed by a single-layer epithelium, which secretes a dense layered cuticle, and powerfully developed muscles. The skin of leeches is rich in glandular cells that secrete mucus and is permeated with a network of lacunar capillaries. Under the epithelium there are numerous pigment cells that cause a peculiar pattern of leeches.

Leeches are characterized by the presence of three continuous layers of musculature of the skin-muscular sac, like in flatworms: the outer annular, diagonal, and the most powerful longitudinal. The dorsoventral muscles, which are not part of the skin-muscular sac, are also strongly developed.

Body cavity and circulatory system

In almost all leeches, the entire space between the organs is filled with parenchyma, like in flatworms. Only in leeches does the parenchyma fill the secondary body cavity, while in flatworms it fills the primary.

In another order - proboscis leeches (Rhynchobdellida) - a stronger growth of the parenchyma is observed. This leads to a partial reduction of the coelom. However, the coelomic cavity is preserved as a whole system of lacunae. Four main coelomic lacunae run along the entire body: two on the sides, one above the gut, surrounding the dorsal blood vessel, and one below the gut, containing the ventral blood vessel and the ventral nerve cord. These gaps communicate with each other, forming a network of smaller gaps. Thus, proboscis leeches have both a circulatory system and a lacunar system, which is a modified coelom.

In the third order - the higher jawed leeches (Gnathobdellida), which include the medical leech and many other freshwater leeches - the process of development of the parenchyma goes as far as in the proboscis leeches. The blood vessels lying inside coelomic lacunae in proboscis leeches are reduced in jaw leeches. The function of the circulatory system is performed by the lacunar system, which originates from the coelom. Such a process of functional replacement of one organ by another, different in origin, is called substitution or replacement of organs.

excretory system

The excretory organs of leeches are represented by segmental organs of metanephridial origin. However, the number of pairs of pephrindia does not correspond to the number of segments. The medicinal leech has only 17 pairs. In connection with the transformation of the coelom into a system of lacunae, the structure of the metanephridia of leeches also changed. Funnels of metanephridia open into the ventral lacuna (general), but not directly into the nephridial canal. They are separated from the nephridial canal by a septum, so the secreted substances diffuse from the funnel into the nephridium.

Such a structure of the metanephridia of leeches (separation of the infundibulum from the nephridial canal) is explained by the functional transformation of the lacunae into the main circulatory system, which replaces the circulatory one. The metanephridia of leeches are characterized by the presence of a special expansion - the bladder.

Digestive system

The mouth is placed on the bottom of the front sucker. It leads to the anterior part of the digestive system, lined with ectoderm and consisting of the oral cavity and muscular pharynx. The structure of the oral cavity and pharynx in proboscis and jaw leeches is different.

In proboscis leeches, the oral cavity, growing back, surrounds the pharynx in the form of a vagina. A very muscular pharynx turns into a proboscis, protruding and retracting with the help of special muscles. The proboscis can penetrate into the thin covers of various animals (for example, mollusks), and in this way the leech sucks out blood.

In jawed leeches (medical leeches, etc.) in the oral cavity there are three longitudinal muscular ridges that form jaws directed with their crests towards each other. Muscular rollers are covered with chitin, serrated along the edge. With these jaws, leeches incise the skin of an animal or person. In the throat of blood-sucking jaw leeches, glands open that secrete a special substance - hirudin, which prevents blood clotting.

Next, food enters the endodermic midgut, which consists of the stomach and posterior midgut. The stomach forms paired lateral protrusions, of which the last pair is usually especially developed, extending to the posterior end of the body. The stomach serves as a reservoir for long-term storage of blood. The blood that fills his pockets does not clot for weeks and months.

The posterior midgut is represented by a relatively short straight tube in which the final digestion and absorption of food takes place. It passes into a short, often enlarged posterior ectodermic gut, which opens with an anus above the posterior sucker.

Nervous system and sense organs

The nervous system of leeches consists of a paired supraoesophageal ganglion connected by circumoesophageal connections with the suboesophageal ganglionic mass. The latter is formed by the fusion of the first four pairs of ganglia of the abdominal nerve chain. This is followed by 21 ganglia of the ventral nerve chain and a ganglionic mass (of eight pairs of ganglia) that innervates the posterior sucker.

The sensory organs of leeches are represented by sensitive kidneys, or goblet organs. Each such organ consists of a bundle of spindle-shaped cells located under the epithelium. The outer end of sensitive cells forms a sensitive hair. Nerves from the ventral nerve cord approach the inner ends of these cells.

Some of the goblet organs perform the functions of chemical sense organs, others - tactile. The eyes of leeches have a similar structure to the goblet organs described above. There may be several pairs. The eye consists of vesicle-shaped photosensitive cells with large vacuoles inside, to which the nerves that make up the axial part of the eye approach. The eye is surrounded by dark pigment.

Reproductive system, reproduction and development

According to the structure of the genital organs and the method of reproduction, leeches have much in common with oligochaetal rings. They are hermaphrodites, and their genitals are concentrated mainly in the region of the 10th and 12th body segments. Leeches have a girdle section, which, unlike oligochaetes, coincides in position with the penis. The girdle becomes noticeable only during the breeding season.

The male reproductive apparatus consists of several pairs (4-12 or more) of the testes. The medicinal leech has 9 pairs of testes located inside the seed sacs. Short vas deferens depart from them, opening into longitudinal paired vas deferens. The latter in the area of ​​the 10th segment form dense balls - appendages of the testes, in which sperm accumulates. Then they pass into the ejaculatory (paired) canals, which open in the copulatory organ, which can protrude forward through the unpaired male genital opening on the 10th segment. Not everyone has a copulatory organ. In many leeches, spermatozoa are enclosed in spermatophores. Spermatophores are either introduced into the female genital opening or stuck into the skin, and the spermatozoa penetrate the body of the leech and make their way to the female reproductive tract.

The female reproductive apparatus consists of a pair of ovaries located in egg sacs. They pass into short and wide uterus, which are interconnected and form an unpaired oviduct, which flows into a wide vagina, which opens on the 11th segment with a female genital opening.

Fertilized eggs are laid in a cocoon secreted by a girdle. The cocoon is either attached to aquatic plants, or is located at the bottom of the reservoir. Some leeches lay single eggs.

The development of leeches is not direct, since larvae emerge from the eggs, remaining, however, in a cocoon. The larvae have cilia and protonephridia. In the cocoon, the transformation of larvae takes place, and already formed leeches emerge from the cocoon into the water. The laying of eggs in relatively strong cocoons, which protect eggs and larvae well, causes a small number of eggs. It is measured in various leeches in units, in extreme cases, in tens.

Classification

The class of leeches is divided into three orders: 1. Bristle-bearing (Acanthobdellida); 2. Proboscis (Rhynchobdellida); 3. Jaw (Gnathobdellida).

Order Bristle-bearing leeches (Acanthobdellida)

A very primitive relic form bearing four pairs of sharp, curved setae on five anterior segments. The anterior sucker is absent, only the posterior one is present. The parenchyma is poorly developed, there is a coelomic cavity and a circulatory system.

Squad Proboscis leeches (Rhynchobdellida)

Proboscis leeches are remarkable for breeding and caring for offspring. The leech lays eggs that remain attached to the ventral side of its body. At this time, the leech is not very mobile: it sits, attached with suckers, on some plant and makes oscillatory body movements. When juveniles hatch from the eggs, the leech does not change its position and the young leeches remain attached to the ventral side of the mother with their suckers, usually for several days, and then spread and begin to lead an independent existence.

Squad Jawed leeches (Gnathobdellida)

Most jaw leeches in the oral cavity have the jaw apparatus described above.

In addition to the medicinal leech (Hirudo medicinalis), common in the southern part of Russia, this order includes the ubiquitous false horse leech (Haemopis sanguisuga). This is a large dark-colored leech, has weak jaws and is not able to bite through the skin of humans and mammals. It feeds on worms, mollusks and other invertebrates. The cocoons of the false-horse leech are buried in the coastal strip, above the water level.

Some jawed leeches (especially those found in southern latitudes) can be human parasites, for example, from the genus Limnatis. One of them - L. turkestanica - is found in Central Asia. When drinking raw water from a reservoir, it can enter the human nasopharynx, where it settles and sucks blood. In addition to severe irritation, it causes bleeding. In the jungles of Sri Lanka, India, Indonesia, land animals from the genus Haemadipsa live. They hide in damp places, in grass and under foliage, and attack animals and humans, causing very sensitive bites.