Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Virology MCQs 1-25
Wed Oct 22, 2014 6:51 am by Johnsnow

» protozoa inactivation
Wed Jun 29, 2011 4:28 pm by Guest

» Contributions of louis pasteur
Sun Jun 07, 2009 6:52 pm by arsham

» Immuno prophylaxis of tetanus
Sat Jun 06, 2009 11:16 pm by sakia_fazal

» pathogenecity of CLOSTRIDIUM PERFINGES
Sat Jun 06, 2009 11:03 pm by sakia_fazal

» naglers reaction
Sat Jun 06, 2009 10:53 pm by sakia_fazal

» LABORATORY DAIGNOSIS OF SYPHILIS
Sat Jun 06, 2009 9:27 pm by sakia_fazal

» Trichomonas vaginalis
Sat Jun 06, 2009 6:31 pm by sakia_fazal

» instestinal ameobiasis
Sat Jun 06, 2009 4:49 pm by sakia_fazal

Shopmotion


Navigation
 Portal
 Index
 Memberlist
 Profile
 FAQ
 Search
Affiliates
free forum
 



The life cycle of S.haematobium

View previous topic View next topic Go down

The life cycle of S.haematobium

Post  sudheerkher on Fri Nov 14, 2008 8:35 pm

The life cycle of S.haematobium_Marwa

Schistosoma haematobium has a complex life cycle, which takes place in humans, and in an intermediate host of a freshwater snail. Schistosoma needs the right conditions to complete its life cycle, including both hosts (humans and snails) and freshwater. Humans become infected when they come into contact with the infective stage of the life cycle (the cercaria) in water, where the snail hosts are found.

1. Eggs are passed out with the urine. If this is into water (e.g. a pond or lake) the eggs will hatch into miracidia.
2. The miracidia enter a fresh water snail (Bulinis sp.).
3. In the snail the larvae go through further stages of development and multiplication.
4. The next stage of the schistosome development is cercaria, which are released from the snail.
5. If these come into contact with humans, e.g. when they are swimming, bathing or wading in the water, the cercariae can enter unbroken skin – often of the feet or ankles (shedding their tail as they do so).
6. Once inside a person, the larvae migrate through the blood system to the liver. In the veins of the liver, the schistosomes undergo further development, and mature into adults.
The adults leave the blood system of the liver to migrate again, finally ending up in blood vessels around the urinary bladder (and less often, other organs). Here eggs are released against the bladder wall. These eggs then penetrate into the inside of the bladder, where they are passed out with the urine – to begin the cycle again.

sudheerkher

Posts : 65
Join date : 2008-11-12
Age : 68
Location : Ajman, UAE

View user profile http://drsudheerkher.shutterfly.com/

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum