A.Lumbricoides Flashcards
(23 cards)
What is the common name for Ascaris lumbricoides?
Giant roundworm
What is the primary habitat of Ascaris lumbricoides in humans?
Small intestine
Describe the general morphology of Ascaris lumbricoides adult worms.
Large, broad, light pinkish/whitish, cylindrical body, tapering at the anterior end and somewhat less at the posterior end. Mouth opens at the anterior end with 3 finely toothed lips.
What two substances do Ascaris lumbricoides produce to protect themselves or suppress host immunity?
P13 pepsin inhibitor 3 (protects worm from digestion) and phosphorylcholine (suppresses lymphocyte proliferation).
Describe the morphology of an adult male Ascaris lumbricoides.
15-30 cm in length, 3-4 mm in diameter. Posterior end is curved ventrally to form a hook. Presence of a pair of copulatory spicules of equal size.
Describe the morphology of an adult female Ascaris lumbricoides.
25-40 cm in length, 5 mm in diameter. Tail is straight and conical. Lays nearly 200,000 eggs daily.
What is the mode of transmission for Ascaris lumbricoides?
Ingestion
What is the infective stage of Ascaris lumbricoides?
Embryonated egg
What are the diagnostic stages of Ascaris lumbricoides?
Larvae, fertilized & unfertilized egg
Describe the typical shape, size, and color of a fertilized Ascaris egg.
Round/oval, measures 60-70 um in length and 40-60 um in breadth. Bile-stained and brown in color.
Describe the layers of a fertilized Ascaris egg.
Surrounded by a thick, transparent shell consisting of a non-permeable innermost lipoidal vitelline membrane; a thick, transparent middle layer; and an outermost coarsely mammillated albuminoid layer.
Do fertilized Ascaris eggs float in saturated common salt solution?
Yes, they float.
Describe the typical shape, size, and appearance of an unfertilized Ascaris egg.
Narrower & longer, measures 90 um in length & 55 um in breadth. Bile-stained & brown in color. Contains a small, atrophied ovum & a thin shell with an irregular coating of albumin.
What layer is typically absent in unfertilized Ascaris eggs compared to fertilized eggs?
Innermost lipoidal vitelline membrane of the parasite shell.
Do unfertilized Ascaris eggs float in saturated common salt solution?
No, they do not float.
What general term describes the disease caused by Ascaris lumbricoides?
Ascariasis
How do Ascaris lumbricoides infections affect the nutritional status of individuals?
Affect the nutritional status, leading to malnutrition.
What specific intestinal problems can Ascaris lumbricoides cause?
Loss of appetite & obstruction of the intestinal tract.
What substance released by Ascaris lumbricoides can lead to allergic manifestations?
Toxic body fluid (ascaron)
Name some laboratory diagnostic methods for Ascaris lumbricoides infection.
Demonstration of adult worms; demonstration of larvae (detected in sputum during migration); demonstration of both fertilized & unfertilized eggs (DFS & Kato-Katz); Serodiagnosis; Eosinophilia (seen in larval invasion stage).
What is the migration route of Ascaris lumbricoides larvae in the human body?
Heart-lung migration
Name some common anthelmintic drugs used to treat Ascaris lumbricoides infection.
Pyrantel pamoate, Albendazole, Mebendazole, Piperazine citrate.
What are some key prophylactic measures against Ascaris lumbricoides infection?
Proper disposal of feces; avoidance of eating raw meat or vegetables; periodic treatment with an effective anti-helminthic; WASHED (implies proper hygiene and sanitation).
