Question

Describe the fate of aortic arches 1-6, the ventral aorta, and dorsal aorta for each of the following vertebrate groups:

a. Chondrichthyes

b. Actinopterygian (Teleost) fish

c. Sarcopterygian (Dipoan/Lungfish) fish

d. Anurans (larva and adult frogs)

e. Non-avian Reptiles

f. Birds

g. Mammals

When describing these fates, be sure to include whether blood is passing through a gill capillary, lung, or bypassing a respiratory organ altogether. Also mention important blood vessels that form from each aortic arch

Answer 1

Chondrichthyes-(e.g.Shark)-

The first arch does not form. Instead, the afferent and efferent spiracular arteries form from arch II.

The evolution of aortic arches and cardiac chambers in vertebrates. Primitive fishes, represented by sharks, have six paired gill arches. ... During air respiration, the blood is shunted through arches three and four, while the ductus arteriosus in arch six shunts oxygen-poor blood away from the gills and to the lungs

Actinopterygian Fishes:  Arches I and II are lost, and only four pairs of aortic arches develop.

Sarcopterygian:A small spiracle is generally present, and arch I is reduced. In the Australian lungfish, all gills are functional, but in the African and South American lungfishes, arches III and IV lack gills. In all lungfishes, a pulmonary artery breaks off from arch VI and connects to the lung.

Amphibians: (Anurans)-

In anurans (adult), only three pairs of aortic arches (III, IV and VI) are present. But in the tadpole the development of aortic arches cor­respond to the emergence of external and internal gills .it shows the fate of aortic arches in some amphibians.

In adult amphibians, the gill arches are lost and the aortic arch vasculature remains bilaterally symmetrical. Oxygenated and de-oxygenated blood enter the ventricle through the right and left atrium and leaves the heart through a single outflow tract containing a spiral valve. Anteriorly the bulbus arteriosus gives rise to three pairs of arteries (aortic arches) to each of the three pairs of external gills. ... In the frog there are no aortic (arterial) arches in either the mandibular or hyoid (first or second visceral) arches.

The first two arches are lost. Larval salamanders have gills on III, IV, and V. Arch VI has a pulmonary artery. As the salamander metamorphoses, the carotid duct between III and IV disappears. The internal carotid still is needed to provide blood to the brain, but it connects to the external carotid, and the part of the ventral aorta between III and IV is now called the common carotid artery.

Reptiles:(Non-avian)-e.g.Lizzard-

Arches III, IV, and VI are retained, but most of the additions and modifications occur on IV. The ventral aorta splits to form the left and right arches of the aorta and the pulmonary trunk, which incorporates the sixth arch and its connections to the lungs. The left aortic arch combines with the left half of arch IV and continues to the left dorsal aorta, forming the left systemic arch. The right systemic arch includes the right aortic arch, which combines with the right half of arch IV. These two arches unite behind the heart to form the common dorsal aorta.

Birds:  The left systemic arch does not develop, and all functions are carried out by the right systemic arch. The subclavians arise from the internal carotids instead of the dorsal aorta. Most of the blood goes into the arch IV. Arch III remains as a shunt between the external and internal carotids. VI is still joined with the pulmonary trunk to the lung.

Mammals:  Similar to birds, except that the left systemic arch develops and the right does not. The right subclavian leads off the dorsal aorta, and the left comes off the left systemic arch.