Biological mapping experiments on earthworm-like roundworm nematodes (Ascaris lumbricoides)
Biological mapping experiments on earthworm-like roundworm nematodes (Ascaris lumbricoides)
Application: (1) Observe the appearance of adult Ascaris lumbricoides and identify male and female; (2) Master the morphological characteristics of Ascaris lumbricoides eggs; (3) Observe Ascaris lumbricoides pathological specimens to deepen the understanding of Ascaris lumbricoides pathogenicity.
Operation method
morphological observation
Principle
The specimen is viewed under the mirror with the left eye, while the right eye looks out of the mirror and draws. Dots and lines drawn in pencil are usually used to form an outline drawing (dot and line drawing), without the use of underlining. Some parts (e.g. Plasmodium) can be drawn with red or blue pen. The drawing should be based on the characteristics of the specimen, be accurate, true, have the necessary characteristics, and can reflect the proportion of the size of the specimen. The drawing should be neat and tidy, and each part of the drawing should be annotated (with the name of the structure), the annotation should be on the right side, and the annotation should be clear and accurate. The lines should be parallelized as far as possible.
Materials and Instruments
Ascaris lumbricoides Move I. Adult Caveat If the protein membrane of Ascaris lumbricoides eggs is detached, the egg shell becomes colorless and transparent, and care should be taken to distinguish it from other nematode eggs. Common Problems 1. Faecal examination of Ascaris lumbricoides eggs (fertilized and unfertilized) The physiological saline direct smear method can meet the diagnostic requirements. Physiological saline direct smear method can meet the diagnostic requirements, precipitation method and floating polymerization method can also be used, with better detection effect, but the effect of unfertilized Ascaris lumbricoides eggs detection is poor. 2. 2. Detection of Ascaris lumbricoides in sputum is used for the diagnosis of pulmonary ascariasis or allergic pneumonia caused by Ascaris lumbricoides larvae. 3. 3. Deworming therapeutic diagnosis According to the morphologic characteristics of adult worms for identification. For more product details, please visit Aladdin Scientific website.
physiological saline
microscope
1. Liquid-immersed macroscopic specimen (visual observation, manipulation):
Large nematode parasitizing the human body, long cylindrical, resembling an earthworm, yellowish or creamy white after fixation. The body surface has obvious fine transverse lines, and there are two longitudinal lateral lines and a dorsal line and a ventral line. Female worm tail bluntly rounded, anatomical specimens, reproductive organs for the two-tube type, in addition to the intestinal tubes are reproductive system; therefore, strong reproductive capacity to produce a large number of eggs. In males, the tail is curved toward the ventral surface, and in anatomical specimens, the reproductive organs are of the single-tube type, and the digestive tract is simple. Sometimes a pair of sickle-shaped symphysis spines can be seen.
2. Adult Ascaris lumbricoides slide specimen (demonstration):
The three lumbricoides are arranged in a zigzag shape, with a larger one on the dorsal side, and the orifice is located in the center.
3. Male Ascaris lumbricoides slide specimen (demonstration):
A pair of sickle-shaped symphysis spines protrudes out from the cloaca.
4. Ascaris lumbricoides cross-section slide specimen (manipulation):
Ascaris lumbricoides has a three-layered body wall: the outer layer is the corneal cortex, the middle one is the hypodermis, and the inner one is the muscularis propria. The body wall is divided into three layers: an outer layer of cuticle, a middle layer of subcutis, and an inner layer of muscle. The subcutaneous layer is thickened along the dorsal, ventral and lateral sides of the body cavity, forming four longitudinal cords. The dorsal and ventral longitudinal cords contain nerve trunks; the lateral cords are thick and contain excretory ducts. The muscular layer consists of a single longitudinal row of myocytes. The numerous and long myocytes are called polymyxoid. In the center is a section of the intestinal tube. Between the intestinal canal and the body wall is the genital canal section, and the eggs can be seen in the uterine section of the female.
II. Fertilized egg slide specimen (microscopic observation, manipulation):
1. Fertilized egg: broadly oval, usually with an uneven protein film on the surface, often stained brownish-yellow by bile; size 45-75x35-50um, thick and transparent eggshell; inside the egg there is a large, round, undivided oocyte, with crescent shaped spaces between the ends of the oocyte and the eggshell. If the oocyte has divided and developed, the gap will disappear.
The protein membrane of the fertilized egg can sometimes be completely detached or partially retained. In this case, the protein membrane is removed from the fertilized Ascaris lumbricoides eggs, which are often colorless and transparent, and should be distinguished from other eggs.
2. Unfertilized eggs: long oval, with thin protein membrane and eggshell; the size of 88-94x39-44 um, the eggs contain a lot of refractive particles of varying sizes with strong reflectivity (yolk particles). Sometimes the protein membrane can also be detached, at this time colorless.
[Lab Report]
Draw a line drawing of the dots of a fertilized and unfertilized egg.