Login

Please Explain Life Cycle of Plasmodium(Including Exo Erythrocytic, Erythrocytic and sporogonic Cycle) In Complete Detail.

Dear student.
 

Plasmodium is a pathogenic parasitic protozoan belonging to the genus Plasmodium and containing over 200 species. The most common species being the malarial pathogen. It causes malaria in humans.

Life cycle of Plasmodium- 
Plasmodium requires two hosts to complete its life cycle.  * When female Anopheles mosquito bites a healthy human being, it releases Plasmodium, which lives in its body as sporozoite (infectious form).  * The parasites multiply (asexual reproduction) in the liver cells and finally burst the liver cells. Sporozoites are released in blood.  * Parasites enter RBCs and further multiply (asexual reproduction) here and finally burst RBCs also.  * Bursting of RBCs is accompanied by release of a toxic substance called haemozoin (associated with fever and chills).  * In the RBCs, only sporozoites change into gametocytes (sexual stage). Gametocytes multiply. * When the diseased person is bitten by a female Anopheles mosquito, gametocytes are introduced into the mosquito.  * Gametocytes fertilise and develop inside the intestine of mosquito to form sporozoites.  * Sporozoites are stored in the salivary glands of mosquito and are released into the healthy person who is bitten by this mosquito.

Exo-erythrocytic cycle,  erythrocytic cycle and the sporogonic cycle are the three phases of the life cycle of Plasmodium. Exo-erythrocytic cycle and erythrocytic cycle take place in the human while sporogonic cycle occurs in the mosquito vector.
The post erythrocytic cycle of Plasmodium is also called as sporogenic cycle.

Regards.

  • 0
View Full Answer
This is done in chapter why do we fall ill
plasmodium need two hosts to complete its life cycle

 
  • 0


The natural ecology of malaria involves malaria parasites infecting successively two types of hosts: humans and female Anopheles mosquitoes. In humans, the parasites grow and multiply first in the liver cells and then in the red cells of the blood. In the blood, successive broods of parasites grow inside the red cells and destroy them, releasing daughter parasites (“merozoites”) that continue the cycle by invading other red cells.

The blood stage parasites are those that cause the symptoms of malaria. When certain forms of blood stage parasites (“gametocytes”) are picked up by a female Anopheles mosquito during a blood meal, they start another, different cycle of growth and multiplication in the mosquito.

After 10-18 days, the parasites are found (as “sporozoites”) in the mosquito’s salivary glands. When the Anopheles mosquito takes a blood meal on another human, the sporozoites are injected with the mosquito’s saliva and start another human infection when they parasitize the liver cells.

Thus the mosquito carries the disease from one human to another (acting as a “vector”). Differently from the human host, the mosquito vector does not suffer from the presence of the parasites.
  • 1
Pls explain sporogonic cycle, and about schizont too
  • 0
What are you looking for?