Biology of the schizont: Difference between revisions
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'''Navigation'''</br> | '''Navigation'''</br> | ||
<span style="font-size: | <span style="font-size:90%">>[[Malaria_Index|Main Malaria Index]]''</span></br> | ||
<span style="font-size:90%">[[Malaria Index | <span style="font-size:90%">>>[[Malaria_Biology|Malaria Biology Index]]''</span></br> | ||
<span style="font-size:90%">> | <span style="font-size:90%">>>>Current page: '''Schizont Biology'''</span> | ||
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<span style="font-size:160%; color:navy">Biology of the Schizont</br></span> | |||
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The stage begins with the first cycle of '''asexual replication''' forming a recognisable “schizont” then concludes when the individual “merozoites” are released to infect new erythrocytes. | The stage begins with the first cycle of '''asexual replication''' forming a recognisable “schizont” then concludes when the individual “merozoites” are released to infect new erythrocytes. | ||
<gallery mode="nolines" widths=300px heights=300px> | <gallery mode="nolines" widths=300px heights=300px> | ||
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(2) This is followed by further cycles of replication </br> | (2) This is followed by further cycles of replication </br> | ||
(3) In this case this results in the formation of 8 daughter parasites </br> | (3) In this case this results in the formation of 8 daughter parasites </br> | ||
(4) The daughter parasites mature and the red cell ruptures to | (4) The daughter parasites mature and the red cell ruptures to release the “merozoites” </br> | ||
(5) The released merozoites very rapidly infect new red cells (so rapid that free merozoites will not usually be seen in blood). | (5) The released merozoites very rapidly infect new red cells (so rapid that free merozoites will not usually be seen in blood). | ||
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|colspan="1" style = "font-size:100%; color:black; background: | |colspan="1" style = "font-size:100%; color:black; background: gainsboro|'''Morphological features and relevance''' | ||
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(1) '''The number of replication cycles differs between species:''' the typical number of merozoites formed differs between species with as few as 8 (in P.malariae) up to a possible 32 (in P.vivax)</br> | (1) '''The number of replication cycles differs between species:''' the typical number of merozoites formed differs between species with as few as 8 (in P.malariae) up to a possible 32 (in P.vivax)</br> | ||
(2) '''This stage may not always occur in blood:''' schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe | (2) '''This stage may not always occur in blood:''' schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe | ||
</br> | </br></br> | ||
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File:Schizontreal4.jpg|Mature schizont releasing merozoites|link={{filepath:Schizontreal4.jpg}} | |||
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<span style="font-size:10%"></span> The progressive maturation of this parasite stage means that they have a wide range of morphological forms. However, these can be readily recognised on blood films by reference to their biology | |||
-------- | [ [[Images of schizont morphology|See clinical images illustrating schizont development]] ] | ||
Relevance of schizonts to | |||
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|colspan="1" style = "font-size:100%; color:black; background: gainsboro |'''Relevance of schizonts to clinical biology''' | |||
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The release of merozoites from schizonts exposes the body to large amounts of free parasite antigens no longer contained within the erythrocytes - the result is an immune response causing high fever and illness symptoms. In some cases the development of parasites is synchronous so that all schizonts mature and release their merozoites at the same time - although rarely seen now, this pattern of development may produce a pattern of remitting fever with a distinct periodicity depending on species: underlying the older descriptive terms tertian or quartan malaria. | |||
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Latest revision as of 18:02, 6 November 2024
Navigation
>Main Malaria Index
>>Malaria Biology Index
>>>Current page: Schizont Biology
Biology of the Schizont
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The stage begins with the first cycle of asexual replication forming a recognisable “schizont” then concludes when the individual “merozoites” are released to infect new erythrocytes.
The progressive maturation of this parasite stage means that they have a wide range of morphological forms. However, these can be readily recognised on blood films by reference to their biology [ See clinical images illustrating schizont development ]
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