Vertebrates generally have a ventral aorta and dorsal aorta, with six pairs of aortic arches that branch off and pass through gill arches. In fishes, the six pairs of arches each pass blood through the gills. Over time, some arches reduce or disappear, with sharks having five pairs and most fish having four functional pairs. In land vertebrates like reptiles, amphibians, birds and mammals, the number of arches reduces further to three pairs or less as lungs replace gills and the circulatory system evolves to separate oxygenated and deoxygenated blood.

3. In vertebrate major arterial
channels include a ventral aorta
and a dorsal aorta and usually 6
pairs of aortic arches .
Blood leaves the heart through
ventral aorta and through the
external carotid arteries into head.
Ventral aorta gives off 6 pairs of
aortic arches running through the
visceral arches.
Each aortic arch having afferent
branchial artery carrying venous
blood to capillaries in a gill.

4. A dorsal efferent branchial arteries
taking arteriole blood from the gill.
 All efferent branchial arteries of
the same side dorsally join a lateral
dorsal aorta which extend into head
as the internal carotid artery.
 each lateral aortae units to form a
single median dorsal aorta which
continue into tail region as caudal
artery.
Branches from these main arteriole
channels supply all parts of the
vertebrate body

5.  Fishes having 6 pair of aortic
arches each passes through gill.
Adults no is reduced to 4 or 5.
In shark only 5 pairs (II, III, IV, V,
VI) are functional.
In teliost fish I, II are tend to
disappears so 4 arches are functional.
Fishes

6.  Lives in water and remain the
extarnal gill in addition lungs.
4 pairs of aortic arches (III to VI)are
present.
Same cases V arch is incomplete.,
reduces or absent.
III arech is carotid arch, IV are
systemic arch, V ductus caroticus, VI
arch pulmocuteneaous atrey or arch
supplying to blood to skin and lung.
Amphibia

7. Reptiles Reptile are fully terrestrial in which gill
are replaced by lung.
3 functional arches are present.
 Entire ventral aorta and conus split
forming only 3 trunk- two aortic or
systemic and one pulmonary.
 Right systemic arch (IV) leads to right
ventricle carrying the deoxygenated blood
or mixed blood.
 Ductus caroticus and ductus arteriosus
are absent .

8.  Warm blooded animal and ventricle
completely divide so no mixing of
oxygenated and deoxygenated blood.
6 arches are develop in the embryo but 3
arches are (III, IV, VI) present in adults.
Ventral aorta is replaced by two
independent aortae or trunks, systemic and
pulmonary.
Arch IV is single systemic aorta, right in
birds and left in mammals, emarging from
left ventricle and carring oxygenated blood.
Birds and Mammals

9. Arch III with remain part of the other lost
systemic arch is represented by a subclavian
artery left side in birds and right side in
mammals.
Arch VI with remnants of lateral and
ventral aortae represents carotid arteries,
which arise from systemic aorta.
Arch VI forms a single pulmonary trunk
taking deoxygenated blood from right
ventricle to the lungs.