PRE FI: INTESTINAL NEMATODES

Question 1

 NON - SEGMENTED elongate, cylindrical worms with a well -developed digestive tract and reproductive system.
 The adult worms have separate sexes, with the male generally SMALLER than the female.
 Have very diverse life cycles providing different routes of transmission as well as disease symptoms.

Answer 1

INTESTINAL NEMATODES

Question 2

 Causes ASCARIASIS in humans
 The MOST COMMON intestinal nematode
 “GIANT ROUNDWORM”
 Is a soil-transmitted helminth (STH)
 STH infections are diseases of poverty, and contribute to malnutrition and impairment of cognitive performances
 Primary hosts: Humans and Swine
* has a so-called “POLYMYARIAN TYPE” of somatic muscle arrangement
- CAPABLE OF HEART LUNG MIGRATION
- MOT: Contaminated food and water  Hand to mouth route contaminated with

Answer 2

Ascaris lumbricoides

Question 3

INFECTIVE STAGE OF Ascaris lumbricoides

Answer 3

FULLY EMBRYONATED EGG

Question 4

Ascaris lumbricoides produce ________ that PROTECTS WORMS FROM DIGESTION and phosphorylcholine that suppresses lymphocyte proliferation.

Answer 4

pepsin inhibitor 3 (PI-3)

Question 5

• Color: creamy white color with a tint of pink
• tapered – end; 1 to 35 cm in length
• female are larger in size and have a genital girdle
• Have a terminal mouth with three lips and sensory papillae

Answer 5

Ascaris lumbricoides ADULT WORM

Question 6

• 22 to 35 cm in length
• smooth striated cuticles
• have paired reproductive organs in the posterior two-thirds

FEMALE OR MALE?

Answer 6

Ascaris lumbricoides FEMALE ADULT WORM

Question 7

• 10 to 31 cm
• ventrally curved posterior end with two spicules
• Single, long, tortuous tubule.

FEMALE OR MALE?

Answer 7

Ascaris lumbricoides MALE ADULT WORM

Question 8

Ascaris lumbricoides SHAPE OF OVA/EGG
- no chitin/shell
o Infective stage
o Contains larvae
o can survive in moist shaded soil

Answer 8

EMBRYONATED EGG

Question 9

Embryonation taks about?

Answer 9

2 - 3 weeks

Question 10

Ascaris lumbricoides SHAPE OF OVA/EGG

o measure 88 to 94 μm by 39 to 44 μm,
o longer and narrower than fertile eggs
o THIN SHELL and irregular mammilated coating filled with refractile granules

Answer 10

UNFERTILIZED EGG

Question 11

Ascaris lumbricoides SHAPE OF OVA/EGG

o spherical mostly
o Mammilated
o thick, transparent, hyaline shell with a thick external layer
o UNEMBRYONATED
o measure 45 to 70 μm by 35 to 50 μm
o have an ovoid mass of protoplasm, which will develop into larvae in about 14 days

Answer 11

FERTILIZED EGG

Question 12

eggs of Ascaris lumbricoides can live up to?

Answer 12

10 years

Question 13

eggs are removed by ______ and killed by ______.

Answer 13

removed by FILTRATION and killed by BOILING

Question 14

developing larvae are destroyed by?

Answer 14

SUNLIGHT AND DESSICATION

Question 15

life span of Ascaris lumbricoides FEMALE ADULT WORM?

Answer 15

1 YEAR

Question 16

Ascaris lumbricoides LIFE CYCLE
- larvae undergo molting in the ____ before migrating to the larynx and oropharynx to be swallowed into the digestive tract

Answer 16

LUNGS

Question 17

hepato-tracheal migration phase takes about how many days?

Answer 17

14 days

Question 18

development of egg-laying adult worms takes about________ after egg ingestion.

Answer 18

9 to 11 weeks

Question 19

A female Ascaris produces about ____ eggs per day, but this number decreases with __________ worm load.

Answer 19

200,000 egg per day; increasing