One of the large parts of protozoology is dedicated to single-celled microorganisms, and protozoan human parasites are considered one of the forms of existence of organisms.
From the standpoint of medical parasitology, which studies the ways and causes of disease, their symptoms (one of the individual signs, frequent manifestation of the disease, pathological condition or disorder of any life process) and treatment methods, protozoa occupy a leading position. This is followed by helminthology aimed at eliminating helminthic invasions and arachnoentomology - systemic methods in medicine that deal with arthropod parasites.
The animal world is abundantly represented by 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 creatures.
Among the free-living single-celled species, there are parasitic forms classified in a separate category that cause serious diseases - protozoonosis, and the corresponding symptoms, says a senior researcher at the medical center.
The simplest have several dozen species of parasites that live to the detriment of the human body. Amoebae are localized in the intestinal tract, causing symptoms (one of the individual signs, a frequent manifestation of any disease, pathological condition or disorder of any vital process) of amoebiasis. If it is a dysenteric form of the parasite, then it causes the development of dysentery, as well as Giardia, which causes giardia. The soft tissues of the internal organs can be affected by plasmodia and toxoplasmosis, which causes unpleasant symptoms of toxoplasmosis, which requires special treatment.
Structure of unicellular organisms
The body of a microorganism is just one cell, which includes the nucleus and cytoplasm. It is lined with a cytoplasmic membrane that contains organelles - endoplasmic reticulum, ribosomes, Golgi apparatus and mitochondria. They all provide the processes of nutrition, respiration, movement, metabolic processes and excretion.
The body of a single-celled organism has both a constant and a variable shape (it 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 line points). Some representatives of protozoa have symmetrical bodies, and some asymmetrical body shape. Representatives of flagellated parasites look like a spindle. Rhizomes of shape (can mean: shape of an object - mutual arrangement of boundaries (contours) of an object, object, as well as the relative position of straight points) do not have a body. in general.
Cells divide by simple mitosis, but in some species sexual reproduction occurs in the process of reproduction with the formation of the zygote. Almost all the simplest organisms are heterotrophs, but there are also autotrophic species of single-celled parasites.
Motor function is produced in the amoeba due to the pseudopodia, it seems to overflow, expelling the pseudopodia. Ciliates move because of the often shortening cilia that abundantly cover their body. The movement of the flagella is due to the movement of the flagella themselves, which is why they got their unpretentious name.
The process of feeding the amoeba is also associated with pseudopodia, wrapping food with pseudopodia and absorbing it. Some forms feed on cellular mouths. Digestion is done by phagocytosis - the internal process, as well as pinocytosis - the process of external absorption of food by the entire body surface.
The main characteristic of protozoa after the appearance of unfavorable conditions is the formation of cysts. The process of cyst formation for dysenteric amoeba is especially characteristic. It allows the parasite (one of the types of coexistence of organisms) to maintain its vital abilities during the period of prolonged anabiosis.
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-preservation of its structure and organization, and ability to reproduce them) are divided into four main classes:
The sarcode class includes one of the most common, dangerous to humans, single-celled parasite - dysenteric amoeba, which exists in the form of 4 different forms:
- The vegetative form is the largest and reaches a size of 20 microns. The finding of a parasite in a freshly excreted stool 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 amoebic intestinal mucosa occurs in a specific way.
- Translucent, or the main form of dysenteric amoeba that lives in the lumen of the colon. This form causes the characteristic symptoms of this disease. They are observed in the process of remission of the patient or in the phase of carrying. The presence of parasites was not determined in the stool of any nature.
- The precision form of the amoeba is fixed in the semi-formed feces of the human carrier of the disease or in the patient in the recovery phase.
The main symptoms of diseases caused by amoebic forms are manifested by constant sharp pains in the lower abdomen, frequent bowel movements with brown stools due to blood content and streaks of mucus. Body temperature remains within normal limits. A similar picture can periodically follow the patient for several years and leads 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 flagellate, or flagellate
A characteristic feature is equipping the body with the simplest organs of movement - one or more flagella. Pathogens of widespread microorganisms of this class are:
- trypanosomes, which cause African sleep sickness;
- leishmaniasis that causes urban or rural leishmaniasis;
- trichomonas - the cause of trichomoniasis, mainly of vaginal form;
- Giardia is the protozoan that causes giardia.
Typical representatives of sporozoans are malarial plasmodium, which causes symptoms of valaria and toxoplasmosis, causing noxoplasmosis.
For microorganisms of this class, the characteristic feature is the presence of cilia in the whole body of the microorganism. They perform a motor function, thanks to which ciliates have the ability to move quickly. The representative of the class is balantidia - the largest human parasite from the protozoan family. It causes a serious and severe disease, balantidiasis, on the background of the ulcerative process. The disease takes place in an acute subclinical form and can be fatal.