Question

describe evolution of Auritic Arches in various groups of vertebrates​

Answer 1

The ventral segments are responsible for the formation of the pulmonary arteries bilaterally. The left ventral arch also contributes to the formation of the pulmonary trunk. The right dorsal arch regresses. The left dorsal arch forms the ductus arteriosus, which later closes and is termed the ligamentum arteriosum.

Answer 2

Answer:

ans

Explanation:

The evolution of aortic arches and cardiac chambers in vertebrates. (A) Primitive fishes, represented by sharks, have six paired gill arches. (B) In teleosts, the gill arch arteries are reduced to form four pairs in the caudal branchial arches. (C) Lungfish have both gills and a pulmonary circulation with the gill arches corresponding to arches two, five, and six. 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. (D) 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. (E) In mammals, the fourth aortic arch arteries become bilaterally asymmetrical and the outflow tract separates into two distinct outflow vessels. (F) Birds also have a completely divided outflow tract with asymmetrical aortic arch arteries. (G) In reptiles such as the turtle, aortic arch artery four remains bilateral but is divided at the base of the outflow tract. The outflow tract is divided into three arteries: right and left aortic arch arteries and the pulmonary artery. In all figures cranial is to the top and caudal is to the bottom.

2.The cardiac neural crest cells (CNCCs) have played an important role in the evolution and development of the vertebrate cardiovascular system: from reinforcement of the developing aortic arch arteries early in vertebrate evolution, to later orchestration of aortic arch artery remodeling into the great arteries of the heart, and finally outflow tract septation in amniotes. A critical element necessary for the evolutionary advent of outflow tract septation was the co-evolution of the cardiac neural crest cells with the second heart field. This review highlights the major transitions in vertebrate circulatory evolution, explores the evolutionary developmental origins of the CNCCs from the third stream cranial neural crest, and explores candidate signaling pathways in CNCC and outflow tract evolution drawn from our knowledge of DiGeorge Syndrome. Birth Defects Research (Part C), 2014. © 2014 Wiley Periodicals, Inc.