Morphological observation experiments on earthworm-like roundworm nematodes
Morphological observation experiments on earthworm-like roundworm nematodes
This experiment is from the official website of Parasitology, School of Medicine, Shandong University.
Operation method
Morphological observation experiments on earthworm-like roundworm nematodes
Principle
Ascaris lumbricoides, or roundworm for short, is the largest of the intestinal nematodes that parasitize the human body, and the adult worms parasitize the small intestine of humans, causing ascariasis (roundworm disease). Canine bowhead nematode (Tosocaracanis), short for canine roundworm, is a common parasite of canines, but its larvae are able to migrate in the human body, causing visceral larva migrans (VLM). Roundworms parasitize the small intestine in humans. The eggs are casually discharged and develop into infective eggs in the outside world. After being swallowed, the larvae hatch in the small intestine, migrate to the lungs through the blood circulation, and then enter the digestive tract and develop into adult worms, which are cylindrical in shape, flesh-red in color when they are alive, and grayish-white when they are dead. Both ends are pointed and thin, and the body surface is smooth and finely grained. The females are larger, with a thin, pointed posterior end, while the males have a curved posterior end. Move 1, their own observation: take roundworm egg slide specimen, use low magnification to find roundworm eggs, find the eggs will be moved to the center of the field of vision. Then change the high magnification lens to observe. Fertilized egg Unfertilized egg adult roundworm (Ascaris lumbricoides), a human parasite petal For more product details, please visit Aladdin Scientific website.
(1) Fertilized egg: broadly oval, yellow, average size 60×45 microns. The egg shell is thick, with a rough and uneven protein film on the exterior of the shell. The egg contains a round oocyte, and in fresh specimens there is a crescent-shaped space between each end of the oocyte and the oocyte shell.
(2) Unfertilized egg: long oval, thin shell, also with a rough and uneven protein film on the outside of the shell, no oocyte is visible in the egg, only the yolk granules which are highly reflective. 
(1) Adult Ascaris lumbricoides: Observe with the naked eye, noting its shape, size, color, and the difference between male and female.
Adult roundworms are long cylindrical, yellowish-red when alive and grayish-white when dead. There is a white lateral line on each side of the body of the insect. The head has three labellums, arranged in a "zigzag" shape. Males are smaller, with the tail curved towards the ventral surface. Females are larger, with a vertical tail, a genital ring at the junction of the first 1/3 of the body, and a genital pore opening on the ventral surface of the ring. 
(2) Ascaris lumbricoides life history (bottled specimen) Note the site of parasitism, stage of infection and mode of infection of the adult worms.
(3) Ascaris larva-containing eggs: the infective stage of Ascaris lumbricoides, note that the eggs contain a coiled larva.
(4) Ascaris lumbricoides head labellum (lateral and apical view), note the arrangement of the three labellums. This is one of the characteristics of Ascaris lumbricoides and is an important basis for identifying Ascaris child worms.
(5) A case of ocular ascariasis (child worm burrowing out of the tear sac)
The child, ×××, a one-year-old female, was admitted to the Municipal Children's Hospital with fever and cough for three days.
During hospitalization, one morning, the parents found that a small white worm was exposed and wriggling in the child's right tear duct, so she went to the emergency ophthalmology department of the Second Municipal Children's Hospital.
Past history: The child had vomited some white thread-like worms a few days before, and at that time there were several of them in the nasal cavity in addition to the oral cavity.
Examination: The child was conscious and there was a white worm at the right tear duct, with one end exposed, about 1 to 2 mm thick, and the exposed part was about 5 mm long, and it kept swinging.
Treatment: Two small white worms about 7-8 mm long and 1.5 mm thick were successively removed from the lacrimal sac with two forceps in a relay fashion.
Diagnosis: Child worms identified as Ascaris lumbricoides (drilled into the lacrimal sac)
(6) A large vat of Ascaris lumbricoides (304 worms) was removed from the intestine of a 6-year-old child with Ascaris lumbricoides intestinal obstruction as a specimen.
(7) Ascaris remnants in the gallbladder: note the remnants of the roundworm's skin after the roundworm has been digested in the gallbladder.