عين النسر
المدير العام
رقم العضوية : 1
 عدد المساهمات : 2247
نقاط : 15980
تاريخ التسجيل : 25/02/2010
 |  موضوع: البوم لبويضات ال Trichuris trichiura  السبت 10 أبريل - 16:35:19 | |
| Trichuris
trichiuraT. trichiura
eggs.
Trichuris trichiura eggs are 50-55
micrometers by 20-25 micrometers. They are barrel-shaped, thick-shelled
and possess a pair of polar “plugs” at each end. The eggs are
unembryonated when passed in stool.
 |  |
A
| B |
A: Egg of T. trichiura in an iodine-stained wet mount.
B: Egg of T. trichiura in an unstained wet mount.
 |  |
C
|
D |
C: Egg of T. trichiura
in an unstained wet mount.
D: Eggs of T. trichiura in a wet mount, showing
variability in size in the species.
 |  | | E |
F |
E: Egg of T. trichiura
viewed with UV microscopy.
F: Egg of T. trichiura in an unstained wet mount of stool.
Notice also the presence of a cyst of Entamoeba coli (arrow).
Life cycle of T. trichiura  <table border="2" cellspacing="2"><tr>
</tr>
</table>
The unembryonated eggs are passed with
the stool
 . In the soil,
the eggs develop into a 2-cell stage
 ,
an advanced cleavage stage
 ,
and then they embryonate
 ;
eggs become infective in 15 to 30 days. After ingestion
(soil-contaminated hands or food), the eggs hatch in the small
intestine, and release larvae 
that mature and establish themselves as adults in the colon
 . The adult worms (approximately
4 cm in length) live in the cecum and ascending colon. The adult worms
are fixed in that location, with the anterior portions threaded into the
mucosa. The females begin to oviposit 60 to 70 days after infection.
Female worms in the cecum
shed between 3,000 and 20,000 eggs per day. The life span
of the adults is about 1 year.
| | |
|
.jpg)
