Nematoda & Acanthocephala

Question 1

Class nematoda belongs to phylum:

Answer 1

Nemathelminthes (roundworms)

Question 2

Class Acanthocephala belongs to phylum:

Answer 2

Acanthocephales

Question 3

Describe class Acanthocephala:

Answer 3

Thorny-headed worms or spiny-headed worms

Question 4

Name subclasses of class Nematoda:

Answer 4

Adenophorea
Rhabditida
Strongylida
Ascaridida
Oxyurida
Spirurida

Question 5

Describe class Nematoda:

Answer 5

Cuticle with circular striations causes pseudosegmentation
Cuticle lines the esophagus and rectum
Epicuticle is a thin layer of lipids and proteins
Hypodermis is a thin layer of tissue immediately underneath the cuticle
Lateral hypodermal cords contains cells and nuclei of hypodermis, and extrude into the pseudocoelom
Dorsal and ventral chords are formed by extensions of the hypodermis

Question 6

What is the pseudocoelom of Nematoda?

Answer 6

It arises from embryonic blastocoel and is where the lateral hypodermal chords extrude into

Question 7

Describe the digestive system of Nematoda:

Answer 7

Straight tube consisting of the buccal cavity (stoma, mouth), esophagus, esophago-intestinal valve, intestine and rectum (cloaca in males).

Question 8

Head region of nematodes is:

Answer 8

adapted to its lifestyle

Question 9

Different types of nematode oesophageus:

Answer 9

1. Rhabditiform
2. Strongyliform
   - bulb-shaped, large posterior swelling
3. Filariform
   - simple and slightly thickened posteriorly
4. Trichuroid
   - single column of cells (stichosome)

Question 10

Describe the nervous system of Nematoda:

Answer 10

Consists of:
* Circumesophageal nerve ring
* 2 or 4 longitudinal nerve rings
Anterior, ventral and dorsal nerve trunks

Question 11

Excretory system of nematodes consist of:

Answer 11

Excretory pores and excretory tubules

Question 12

Female reproductive system of nematodes:

Answer 12

Oviduct
Receptaculum seminis
Ovary
Uterus
Vulva
Vagina
Eggs

Question 13

Male reproductive system of nematodes consists of:

Answer 13

Testis
seminal vesicle
Vas deferens
Ejaculatory duct
Cloaca
Spicula

Question 14

Nematode males are smaller/bigger than females?

Answer 14

Smaller

Question 15

Which nematode does not reproduce sexually?

Answer 15

Strongyloides

Question 16

Cuticula of nematode consists of:

Answer 16

Anterior end - cuticle modification:
* Cephalic vesicle
* Cervical vesicle
* Cervical papilla
* Cervical alae
Posterior end - copulatory bursa
* Spicula
* Gubernaculum (guide for spicules)
* Lateral and dorsal lobe
* Bursal rays
* Dorsal ray
* embraces the female during copulation

Question 17

What are accessory organs in nematodes?

Answer 17

Spicules and gubernaculum

Question 18

Example of nematoda bursata:

Answer 18

Ancylostomaa

Question 19

Example of nematoda non-bursata:

Answer 19

Trichuris

Question 20

Life cycle of nematoda - describe moulting:

Answer 20

4 moulting
Cuticle detach from the hypodermis and is discarded

Question 21

Types of life cycles for nematodes:

Answer 21

Geohelminthes - direct life cycle
Biohelminths - indirect life cycle with intermediate host
Paratenic parasitism

Question 22

What is the infective (larval stage) of nematodes?

Answer 22

L3

Question 23

What are 3 types of nematodes?

Answer 23

Ovipara (eggs placed outside mother’s cavity)
Ovivipara (eggs develop inside the mothers cavity)
Vivipara (offspring is born alive)

Question 24

Describe the life cycle of Strongyles (fam. Trichostrongylidae)

Answer 24

• Direct
• Eggs are passed with feces, release L1
• Moults to L2 and L3
• L3 is ingested by host with herbage
• L3 enter mucosa of small intestine, caecum or colon
• Moult to L4-L5 - adult

Question 25

Describe the life cycle of lungworms:

Answer 25

• Indirect
• L1 passed in feces
  IH: L2–>L3
  Host ingest L3
  –> bloodstream –> lung –> L4-L5 in bronchi and trachea

Question 26

L1 of Trichuris spp. develop inside eggs in:

Answer 26

environment

Question 27

Genus Toxocara and Toxascaris belongs to order:

Answer 27

Ascaridida

Question 28

Describe the egg of Toxocara canis

Answer 28

Medium
3 thick shells
Pitted shell
Unembryonated
1 blastomer
Dark brown

Question 29

Toxocara canis and cati have what migration:

Answer 29

Entero-hepato-pulmonal

Question 30

Infection of T. canis and cati is by:

Answer 30

Peroral
Transplacental (not T. cati)
Transmammary
Paratenic host

Question 31

Toxocara is a:

Answer 31

zoonosis

Question 32

Toxocara causes:

Answer 32

Larva migrans ocularis
Larva migrans cervicalis
Brain and heart leading to death

Question 33

Ancylostoma braziliensis and N. americanus in human causes:

Answer 33

Dermatitis (larva migrans cutanea)

Question 34

Name species of order Rhabditida:

Answer 34

Strongyloides stercoralis
Str. westeri
Str. suis (ransomi)
Str. papillosus
Str. fuelleborni