SHARK - Digestive system of Scoliodon notes

Digestive system of Scoliodon

Functions:

1. Intake of the food
2. Digestion of the food
3. Absorption & assimilation of digestive
4. Component of the food
5. Excretion of undigested food

1. Unit IV
TYPE STUDY: SHARK (Scoliodon)
Asst. Prof. Komal Gaikwad
B.N. Bandodkar College of Science

2. Circulatory system of Scoliodon
Shark’s heart
2 chambered
1 Auricle 1 Ventricle
Type of circulatory system : Closed type

3. A)Components of circulatory system
1.Blood
Colourless plasma & corpuscles


RBC
Nucleated oval cells
Contain respiratory pigment as
haemoglobin
WBC
Defensive ameboid cells

4. 2. Heart
Muscular & tubular heart
Works on principle of suction
Known as venosus or branchial heart, because only
deoxygenated blood is circulated through it

LOCATION: On the ventral side of the body between two series
of gill pouches

6. 2 chambered heart consists of :
1 auricle & 1 ventricle
and
Two accessory chambers (sinus arteriosus and sinus venosus)
Openings of all chambers of heart have guarding muscular valves
Valves prevent any backward flow of the blood

7. Function of heart
To receive the deoxygenated blood from the body and to pump it to the gills for
purification and further supply to the body

HEART GILLS

BODY

8. Receiving parts of the heart

Sinus venosus Auricle

9. Forwarding parts of the heart

Ventricle Conus arteriosus

10. Receiving parts of the heart
1.Sinus venosus
Triangle shaped & thin walled chamber
Tubular & highly contractile
LOCATION: at the base of pericardial cavity
Beating activity originates from this chamber

11. Sinus venosus
has two large veins
Ductus cuveiri
Enter venosus from the
lateral side
&
Two hepatic sinuses

Enter chamber on
posterior side

12. Sinus venosus
Opens into
Auricle by an aperture
Known as Sinu- auricular aperture
Aperture is guarded by membranous valves
Function of valves: Prevent backflow of blood from auricle into
venosus

13. 2. Auricle Known as Atrium
large , triangular & thin walled chamber as well as elastic
Walls thicker than sinus venosus
LOCATION: In Front of venosus & dorsal to ventricle
Auricle receives blood from sinus venosus
It opens in ventricle by a slit like aperture called as - Auriculo- Ventricular aperture
Guarded by a valve made up of two lip like muscular flaps- bilabiate valve
Auricle receives venous blood from all parts of the body

15. Forwarding parts of the heart

1.Ventricle
Thick walled
Oval organ - prominent feature of heart
Ventral side- supported by Coracoid cartilage
Inner surface of ventricle gives many muscular strands, which gives that surface a
spongy texture

16. 2. Conus arteriosus
Stout muscular tube like structure arising from the ventricle
Lumen is facilitated with two transverse rows of semilunar valves
Valves are held in position by fine tendinous threads known as
chordae tendinae
Arises from anterio-posterior free ends of the valves & extend to join the ventricular
wall
Conus arteriosus continues forward as the ventral aorta

17. Ventral aorta and its branches
Arterial system has two distinct categories of arteries
Afferent branchial arteryEfferent branchial artery
Arise from Ventral aorta originate from gills
Bring deoxygenated blood to gills
for oxygenation
Pass oxygenated blood to
different parts of the body
5 pairs of afferent branchial
arteries
9 pairs of efferent branchial
arteries

18. Afferent branchial arteryEfferent branchial artery
Aorta first divides on its anterior end into 2
branches known as innominate arteries
1st to 8th pair of these arteries compose a
series of 4 complete loops around the first 4
gill slits.
3rd, 4th and 5th arteries arise laterally from
the ventral aorta
The blood from 5th gill pouch is collected
by 9th efferent branchial artery
4 complete loops are connected with each
other by a specific short longitudinal
connective.

19. Dorsal aorta & its branches
Dorsal aorta formed by - union of epibranchial arteries
LOCATION: ventral side of vertebral column runs posteriorly till
the end of the vertebral column & continues in the tail as a
caudal artery till the tip of the tail

20. Dorsal aorta gives rise to few branches
1.Buccal & vertebral arteries
2.Pair of small sub-clavian arteries

Branchial artery antero lateral artery dorso lateral artery
To to to
Pectoral girdle body musculature dorsal musculature
& pectoral fin

21. 3. Large coeliaco mesentric artery

Smaller coeliac artery larger coeliac mesentric artery
4. Lieno- gastric artery

ovarian / posterior intestinal posterior gastric splenic
spermatic arteryartery artery artery

22. Venous system (complicated system)
Formed of a network of different veins
Veins- blood capillaries that bring deoxygenated blood from diff parts of body to heart
of animals
Veins in Scoliodon form irregular blood sinuses - a characteristic feature of the venous
system of scoliodon

24. Venous system

Cardinal system Hepatic system ventral system
Anterior Posterior Anterior Posterior
Cardinal cardinal ventral ventral
System system veins veins

25. THANK YOU!