Lesson 2 - Anatomical Structure of Nematode Flashcards
1
Q
body organization
A
a tube within a tube
2
Q
from ectoderm
A
body covering
3
Q
from mesoderm
A
muscle layer
4
Q
from endoderm
A
digestive tract
5
Q
composes the nematode body wall
A
assembly of
- cuticle
- hypodermis
- muscular layer
6
Q
main function of nematod ebody wall
A
hydrostatic-skeletal system
7
Q
provide the turgor-hydrostatic pressure for the animal as a whole
A
pseudocoelom (contains coelomocytes)
8
Q
function of pseudocoelom
A
- lubricant between tissues
- provides a medium for intercellular signaling and nutrient support
- may play a role in storage of vitamin B12, protein synthesis and secretory functions
9
Q
- filled with fluid
- exceptionally high hydrostatic pressure
A
hemocoel
10
Q
esophagus
A
triradiate pharynx
11
Q
is the distance from the extreme anterior end to the base of the lips
A
lip or cephalic region
12
Q
body distance from theb ase of the lips to the posterior end of the pharynx/esophagus
A
esophageal or pharyngeal region
13
Q
region of teh junction of the esophagus and intestine
A
cardial region
14
Q
denotes the distance between the base of the esophagus/pharynx to the level of the vulva
A
prevulval region
15
Q
denotes the area near the vulva
A
postvulval region
16
Q
denotes the area anterior to the cloaca or anus
A
precloacal or preanal region
17
Q
indicates the area near the anus or cloaca
A
anal/ adanal/ cloacal region
18
Q
dentoes the tail region
A
caudal region
19
Q
- covered by a carbohydrate rich surface coat epicuticla
- with aging, its thickness increases due to expansion of the basal zone
A
cuticle
20
Q
covers cuticle
A
epicuticle
21
Q
function of epicuticle
A
important in evasive immune mechanism
22
Q
chief openings of teh nematode that are also cuticle-lined
A
- buccal cavity
- pharynx
- rectum
- excretory duct
- pore
23
Q
zones where cuticle is formed
A
- cortical zone
- median zone
- basal zone
24
Q
contains hihgly resistant protein stabilized by dityrosine cross links
A
cortical zone
25
highly resistant protein
cuticulin
26
stabilizes cuticulin
dityrosine cross links
27
- contains as a minimum inconsistent types of structures
- may serve to strengthen the pore and to keep it open
pharyngeal cuticle
28
inconsistent tyeps of structures
1. bridging cuticle
2. flaps
3. grinder
4. sieve
5. channel
29
well-developed wing-like structures present along entire length of body
lateral alae
30
cuticle may be ornamented with?
- rings
- longitudinal striations
- spikes
- lateral alae
31
wing-like structures found on the anterior part of the body
cervical alae
32
wing-like structures on the tail end of some males
caudal alae
33
- outer most layer of the cuticle
- 6-10 nm thick
- consists of 2 dark lamellae separated by a darker inter space
- contains mitochondria and ER especially at the regions of the cords
epicuticle (hypodermis)
34
thickness of epicuticle
6-10 nm
35
what does the epicuticle consist
2 dark lamella separated by darker inter space
36
what does the epicuticle contain at regions of the cords
- mitochondira
- endoplasmic reticulum
37
2 types of muscles
1. somatic
2. specialized muscles
38
related to the body structure
somatic
39
related to certain parts of the body for particular purpose
specialized muscles
40
two main types of muscle fibers architecture in ?
1. nematodes
2. platymyarian
3. coelomyarian
41
- rather ovoid in cross section
- contains contractile fibers at one side, adjacent to the hypodermis and has a myocyton of about the same width bulging into the pseudocoel
- contains the nuclei, large mitochondria, numerous cristae, ribosomes, ER, glycogen and lipids
platymyarian muscle cell
42
non-contractile cell body of platymyarian muscle cell
myocyton
43
- more spindle shaped with the contractile portion at the distal end of a narrow U
- distal end of the U is placed against the hypodermis
coelomyarian cell
44
nervous system of roundworms
- anterior nervous tissue surrounding the pharynx
- forms dorsal and ventral nerve cords that go from end to end
45
called the circumpharyngeal commissure encircles the isthmus of the pharynx
nerve ring
46
where does the nerve ring encricle
isthmus of pharynx
47
represent chemoreceptors and mechanoreceptors
- sensilla (small sense organs)
- cephalic and caudal papillae
48
- highly variable chemosensory organ
- situated laterally on the head
amphid
49
two kinds of amphid
- spiral
- non-spiral
50
pocket-like structure where the external opeing is in the form of a transverse slit leading to a cavity filld with a gelatinous substance
non-spiral amphid
51
external opening
aperture
52
cavity
fovea
53
gelatinous substance
corpus gelatum
54
fovea is open and elongated, normally turning ventrally (from the nerve) although in a few cases the amphid may be dorsally wound
spiral amphid
55
- observed in male nematodes
- aid in copulation
caudal papillae
56
- paired sense organs, positioned in a bilateral manner close to the point of the tail
- bear unicellular glands opening into a depression in addition to sensory nerve endings
phasmids
57
- male nematode cuticular copulatory organs
- inserted in the female's vulva to attach tot he male to the female and to widen the vulva against the inner body pressure for sperm transfer
spicules
58
copulatory spicules have been shown to contain nerve axons and to posses cholinesterase activity associated with these axons
1. Heterakis gallinarum
2. Nippostrongylus brasiliensis
59
what do the copulatory spicules of _Heterakis_ _gallinarum_ and _Nippostrongylus_ _brasiliensis_ have
- nerve axons
- posses cholinesterase activity
60
what do the position of the nerve axons indicate
spicule is a tactile organ capable of acting as sensory probe during copulation
61
composition of the digestive system
1. stomodeum
2. mesenteron
3. proctodeum
62
consists of the stoma, esophagus, and cardia
stomodeum
63
- known as the midgut
- intestine proper
mesenteron
64
- known as the hind gut
- is the rectum
proctodeum
65
- anterior-most portion of the digestive system
- greatly variable in shape and size in different nematode groups and hence is of extreme importance in taxonomy
stoma
66
two basic types of S-E systems
1. glandular
2. tubular
67
most freeliving nematodes
glandular types
68
found in parasitic nematodes
tubular types
69
- cuticularized structure present in posterior-dorsal side of spicules
- it may be simply trough-like or plate-ike, having the form of a groove
- some free-living forms may have filamentous, ringlike structure
- guide structure of spicule to move
gubernaculum
70
filamentous, ringlike structure through which the spicules move
distal sleeve
71
- helps in proper alignment of sperm transfer
- paired, wing-like cuticular expansion in the region of the tail
- present in most tylenchid nematodes and in some free-living forms
bursa
72
small bursa present in the cloacal region only
adanal
73
large bursa but not covering the tail tip
- leptorderan or
- subterminal
74
bursa covering the entire tail
- peloderan or
- terminal
