title: Third coronary artery: its development and function.
abstract: The third coronary artery arises directly from the aorta and forms anastomoses by the fetal stage. In this study, we used the stereoscope to investigate 622 normal human hearts (from fetuses to adults) and determine the origin of the third coronary artery and variations in positions of origin, bearing in mind the age. The orientation of the third coronary artery orifice is classified into 3 types: 10, 9 and 8 o'clock. There is not significant relative incidence in the 3 types. In connection with multiple third coronary artery orifices, pathologic hearts had a higher incidence than normal hearts but there is no relation to age. Regarding the size of the third coronary artery orifice, a normal heart is smaller than a pathologic heart. The existence of multiple third coronary artery orifices and the fact that pathologic hearts have a higher incidence than normal hearts suggest that the third coronary artery develops and contributes to the collateral circulation after birth.
authors.affiliation: 2nd Department of Anatomy, Toho University School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Miyazaki
authors.forename: M
authors.initials: M
authors.lastname: Kato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries; D002648:Child; D002675:Child, Preschool; D003097:Collateral Circulation; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000196:embryology / Q000254:growth & development* / Q000502:physiology; D005260:Female; D006321:Heart / Q000033:anatomy & histology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged