In fetal life, the lungs are not expanded, so most of the blood from the right ventricle is shunted from the pulmonary artery to the aorta through the patent ductus arteriosus. With a few breaths the lungs expand, and blood flows from right ventricle to pulmonary artery into the lungs. Withdrawal of circulating prostaglandin from the mother plus bradykinins released from the expanding lung of the infant cause the ductus to close over a few minutes to hours. The closed ductus remains as the ligamentum arteriosum.
Matter can be broken down into two categories: pure substances<span> and </span>mixtures.Pure substances<span> are further broken down into elements and compounds. ... A chemical </span>substance<span> is composed of one type of atom or molecule. A </span>mixture<span> is composed of different types of atoms or molecules that are not chemically bonded</span>
It can be classified in the phylum chordata.
Phylum : chordata
Sub-phylum: Vertebrata
Division: Gnathostomata
Superclass: pisces (respiration occurs typically by gills)
