TYPE STUDY OF FASCIOLA HEPATICA, DIFFERENT SYSTEMS

TYPE STUDY OF FASCIOLA

1. BY: DR.MANISHA YADAV
FASCIOLA HEPATICA

2. CLASSIFICATION

3. DEFINITION

6. HABITS
LOCOMOTION: Absent
RESPIRATION: Anaerobic
FEEDING: Bile, blood, lymph, epithelial cells of bile
duct in a holozoic manner. In ingestion is by sucking
action of muscular pharynx while digestion is
intercellular.
REPRODUCTION: Hermaphrodite. Fertilization is
internal. Oviparous, development is indirect
involving polyembryony.

7. Morphology
The morphology of Fasciola hepatica, also
known as the liver fluke, includes the
following characteristics:
 
Size
Fasciola hepatica is one of the largest
flukes in the world, measuring up to 30
mm long and 15 mm wide.
 
Shape
The body is oval, leaf-like, and
dorsoventrally flattened.
 The anterior end
is cone-shaped, while the posterior end is
pointed.
 
Color
The body is pinkish in color, while the
digestive system is dark due to ingested
bile.
 


8. External openings
The fluke has a mouth opening at the front end, a small
genital opening on the ventral side, and a small opening
of Laurer's canal on the dorsal side during the
reproducing season.
 
Suckers
The fluke has two suckers: an oral sucker near the mouth
and a ventral sucker on the ventral side.
 
Tegument
The outer surface of the fluke is called the tegument,
which is made of scleroprotein and protects the fluke
from the host's digestive system.
 

9. APERTURES
Genital aperture
Excretory
pore/Nephidipore
Opening of Laurer’s
canal
Spinnules or Scales

10. Body wall

11. FUNCTIONS OF BODY WALL
Protection
Adhesion
Locomotion
Definite shape
Packing material
Absorption
Respiration
Tegument also plays a key role

12. PARENCHYMA
It fills the space between internal organs
Formative cells form the gonads on sexual maturity
Gives turgidity which helps in a definite body shape
It is the seat of assimilation
It stores the reserve food as glycogen

13. DIGESTIVE SYSTEM
Mouth
Buccal cavity
Pharynx – Its wall has numerous
unicellular glands called pharyngeal
glands
Oesophagous
Instestine- It immediately divides
into rami/crura/limbs. Each ramus
gives rise to diverticulae. Much
branched intestine increases the
surface area of distribution of food.
Compensates the absence of
circulatory system

14. PHYSIOLOGY OF DIGESTION
FOOD- Bile, blood, lymph, and epithelial cells of bile
duct
Ingestion- Holozoic manner, Oral sucker and muscular
pharynx collectively form an effecient suctorial appartus.
Digestion- Completely intracellular or extracellular.
Glandular cells of intestinal caecae secrete digestive
enzymes
Absorption and Distribution- Digested food passes into
the parenchyma by diffusion and then distributed to
other organs. Glucose and fructose directly absorbed
through general body surface

15. RESPIRATORY SYSTEM
Anaerobic respiration
Glycogen break into CO2, fatty acids and energy
CO2 is lost through general body surface
Fatty acids are eliminated by protonephridia

16. EXCRETORY SYSTEM
Both excretion and
osmoregulation are
priorities for Fasciola
hepatica’s excretory
system.
 It is made up of several
flame cells, flame
bulbs, or
protonephridia/
solenocytes that are
connected by a network of
excretory channels.

17. It is formed of two parts:
Flame cells: The flame cells, which are thought to be modified
mesenchymal cells, are numerous, irregularly shaped bulb-like bodies
distributed throughout the mesenchyme of Fasciola’s body.
Each flame cell has a thin elastic wall with pseudopodia-like processes,
a
 
nucleus, and an intracellular cavity with a large number of
long
 
cilia 
originating from basal granules; these characteristics are
defining. The cilia in a living
 
organism 
vibrate like a wavering flame, hence
the name flame cell.
Longitudinal excretory canal: There is an excretory pore
at the posterior end from which arises a longitudinal excretory canal, from
which arise four main branches, two dorsal and two ventral, that subdivide
into numerous small capillaries that anastomose; the capillaries continue
into the intracellular cavity of flame cells. The longitudinal excretory canal
is not lined with cilia, but the capillaries are.

18. PHYSIOLOGY
The excretory byproducts, which are
typically fatty acids and ammonia ,
diffuse from the surrounding
mesenchyme into the flame cells ,
where they are subsequently accumulated
within their intracellular cavities.
By hydrostatic pressure, impurities
move from the intracellular cavities of
flame cells into the excretory ducts,
then into the main excretory canal, and
finally to the exterior through the
excretory pore, as a result of the
vibrating movement of the cilia.

19. NERVOUS SYSTEM
Centralized and
ladder-type nervous
system. It is formed of
2 parts
A) CNS- It is again
formed of 2 parts:
Cerebral-nerve
ring/Brain/Collar
Nerve cords
B) PNS- Nerve cords

20. SENSE ORGANS
Due to well protected endoparasitic habitat of the
host. It is not much affected by environmental
stimuli so it doesnot has special sense organs
Tango receptors over whole body surface and
especially in suckers
Each tangoreceptors is a group of nerve fibres with a
bulb like ending which gives a sensory hair to the
surface
Function: These are tactile receptors, so are sensitive
to touch