One of the great branches of protozoology is devoted to unicellular microorganisms and considers protozoan human parasites as one of the forms of existence of organisms.
From the point of view of medical parasitology, which studies the ways and causes of diseases, their symptoms (one of the individual signs, frequent manifestation of disease, pathological condition or disruption of any life process) and methods of treatment, protozoa occupy a leading position. This is followed by helminthology aimed at getting rid of helminth infestations and arachnoentomology - systemic methods in medicine that eliminate arthropod parasites.
The animal world is represented by an abundance of single-celled microorganisms that live everywhere - from the seabed to the upper atmosphere. They all belong to the sub-kingdom of protozoa or protozoa, which has more than 15, 000 representatives of unicellular beings.
Among the free-living single-celled species, there are parasitic forms classified as a separate category that cause a number of serious diseases - protozoa, and their corresponding symptoms, said a senior researcher at the medical center.
The simplest have several dozen species of parasites that live at the expense of the human body. Amoebae are localized in the intestinal tract, causing symptoms (one of the individual signs, frequent manifestation of any disease, pathological condition or violation of any life process) amoebiasis. If it is a dysenteric form of the parasite, then it provokes the development of dysentery, as well as Giardia, which causes giardiasis. The soft tissues of the internal organs can be affected by Plasmodium and Toxoplasma, causing unpleasant symptoms of toxoplasmosis that require specific treatment.
The structure of unicellular organisms
The body of the microorganism is only one cell, which includes the nucleus and cytoplasm. It is lined with a cytoplasmic membrane containing organelles - the endoplasmic reticulum, ribosomes, the Golgi apparatus and mitochondria. They all provide the processes of nutrition, respiration, movement, metabolic processes and excretion.
The body of a unicellular organism has both constant and variable shape (this can mean: the shape of an object - the relative position of the boundaries (contours) of the object, the object, as well as the relative position of the points on the line). Some protozoa have symmetrical bodies and some have asymmetrical body shapes. Representatives of whipworms look like a spindle. The rhizomes of the shape (this can mean: the shape of the object - the mutual arrangement of the boundaries (contours) of the object, the object, as well as the relative position of the points on the line) have no body at all.
Cells divide by simple mitosis, but in some species, in the process of reproduction, fertilization occurs sexually with the formation of a zygote. Almost all the simplest organisms are heterotrophs, but among them there are autotrophic species of single-celled parasites.
Motor function is produced in the amoeba due to the pseudopodia, it seems to overflow, expelling the pseudopodia. Eyelashes move due to the often shortening eyelashes that cover their body in abundance. The movement of the flagella is due to the movement of the flagella themselves, from which they got their unpretentious name.
The process of feeding the amoeba is also associated with pseudopodia, wrapping food with pseudopodia and assimilating it. Some forms feed on the cell mouth. Digestion takes place through phagocytosis - an internal process, as well as through pinocytosis - a process of external absorption of food from the entire surface of the body.
The main characteristic of protozoa in the occurrence of adverse conditions is the formation of cysts. The process of cyst formation is especially characteristic of the dysenteric amoeba. Allows the parasite (\ one of the species of coexistence of organisms) to maintain its viability during a period of prolonged anabiosis.
The main classes of protozoan parasites (one of the types of coexistence of organisms)
Representatives of unicellular organisms (a living body that has a set of properties that distinguish it from inanimate matter, including metabolism, self-sustaining its structure and organization, and the ability to reproduce them) fall into four main classes:
Sarcode class
The sarcoid class includes one of the most common, dangerous to humans, single-celled parasites - dysenteric amoeba, which exists in the form of 4 different forms:
- The vegetative form is the largest, reaching 20 microns in size. Finding a parasite in freshly sent feces confirms a disappointing diagnosis, the symptoms of which speak for themselves.
- Tissue or pathogenic form of the parasite leading a parasitic lifestyle in the lumen of the colon. The defeat of the amoeba of the intestinal mucosa is produced in a specific way.
- Transparent, or the main form of dysenteric amoeba, which lives in the lumen of the colon. This form causes characteristic symptoms of this disease. They are observed in the process of remission of the patient or in the stage of wearing. The presence of the parasite has not been detected in faeces of any kind.
- The pre-cystic form of the amoeba is fixed in the semi-formed stools of a person carrying the disease or in a patient in the recovery stage.
The main symptoms of diseases caused by amoebic forms are manifested by constant sharp pain in the lower abdomen, frequent bowel movements with brown stools due to blood content and streaks of mucus. Body temperature remains within normal limits. Such a picture can periodically accompany the patient for several years and lead to exhaustion, as well as the development of anemia. With complications caused by the tissue form of the amoeba, and without proper treatment, the patient may die.
Class flagellates or flagellates
A characteristic feature is the equipment of the body with the simplest organs of movement - one or more flags. Widespread pathogenic microorganisms of this class are:
- trypanosomes, which cause African sleeping sickness;
- leishmaniasis causing urban or rural leishmaniasis;
- trichomonas - causes of trichomoniasis, mainly in vaginal form;
- Giardia is a protozoan that causes giardiasis.
sporozoic class
Typical representatives of sporozoites are malarial plasmodium, which causes valaria symptoms, and toxoplasmosis, which causes noxoplasmosis.
ciliated class
For microorganisms of this class a characteristic feature is the presence of cilia in the whole body of the microorganism. They perform a motor function, thanks to which the lashes have the ability to move quickly. A representative of the class is balantidia - the largest human parasite of the protozoan family. Causes a serious and severe disease balantidiasis on the background of the ulcerative process. The disease occurs in an acute subclinical form and can be fatal.