b. Visceral aorta:
It passes through the visceral mass
and supplies blood to the
visceral organs by following branch:
(i) A pericardial branch
(ii) A
gastric branch
(iii) A number of
small intestinal arteries
(iv) A large digestive branch
(v) many renal arteries
2.
Sinuses:
The ultimate branches of the arteries open into wide space without
walls and called blood sinuses. In
Pila
there are four sinuses
(1) Perivisceral
(2) Peri intestinal
(3) Branchio renal
(4) Pulmonary
3.
Veins:
The vein carry venous blood from various part of body to auricle.
(1)Afferent ctenidial vein (2) Efferent ctenidial vein (3) afferent renal vein (4)
Efferent renal vein (5) the pulmonary vein
(III) Blood:
Thin, watery, almost colorless
liquid containing floating
colorless
ameobocytes
. The color of blood is white when it is deoxygenated and faintly
bluish when it is oxygenated. This is due to the presence
of respiratory pigment
haemocyanin
.
