Cardiology Flashcards
(162 cards)
Truncus Arteriosus gives rise to…
Ascending Aorta and pulmonary trunk
Bulbus Cordis gives rise to…
smooth parts (outflow tract) of left and right ventricles
Primitive ventricle gives rise to…
trabeculated left and right ventricles
Primitive atria gives rise to…
trabeculated left and right atria
Left horn of sinus venosus gives rise to…
coronary sinus
Right horn of sinus venosus gives rise to…
smooth part of right atrium
right common cardinal vein and right anterior cardinal vein gives rise to…
SVC
Embryology of truncus arteriosus
1) neural crest migration
2) truncal and bulbar ridges that spiral and fuse to form the aorticopulmonary (AP) septum
3) Ascending aorta and pulmonary trunk
Pathology of Truncus Arteriosus
1) transposition of great vessels- failure to spiral
2) tetralogy of Fallot- skewed AP septum development
3) persistent Truncus Arteriosus- partial AP septum development
Interventricular septum development
1) Muscular ventricular septum forms. Opening is called interventricular foramen.
2) AP septum rotates and fuses with muscular ventricular septum to form membranous interventricular septum, closing interventricular foramen.
3) Growth of endocardial cushions separates atria from ventricles and contributes to both atrial separation and membranous portion of the interventricular septum
Pathology of interventricular septum
1) improper neural crest migration into the truncus arteriosus (TA) can result in transposition of the great arteries or a persistent TA
2) membranous septal defect causes an initial left to right shunt which later reverses to a right to left shunt due to the onset of pulmonary hypertension (Eisenmenger’s syndrome)
Interatrial Septum development
1) Foramen Primum narrows as septum primum grows toward endocardial cushions.
2) Perforations in septum primum form foramen secundum (foramen primum disappears)
3) Foramen secundum maintains right to left shunt as septum secundum begins to grow
4) Septum secundum contains a permanent opening (foramen ovale)
5) Foramen secundum enlarges and upper part of septum primum degenerates
6) Remaining portion of septum primum forms valve of foramen ovale.
7) Septum secundum and septum primum fuse to form the atrial septum
8) Foramen ovale usually closes soon after birth because of increased left atrial pressure.
Pathology of Interatrial Septum
Patent foramen ovale caused by failure of the septum primum and septum secundum to fuse after birth
Fetal Erythropoiesis
1) Yolk Sac: 3-10 weeks
2) Liver: 6 weeks to birth
3) Spleen: 15-30 weeks
4) Bone Marrow: 22 weeks to adult
Fetal Circulation (shunts)
1) blood entering the fetus through the umbilical vein is conducted via the ductus venosus into the IVC to bypass the hepatic circulation
2) Most oxygenated blood reaching the heart via the IVC is diverted through the foramen ovale and pumped out the aorta to the head and body
3) Deoxygenated blood entering the RA from the SVC enters the RV, is expelled into the pulmonary artery and then passes through the ductus arteriosus into the descending aorta.
Umbilical Vein
Ligamentum teres hepatis, contained in falciform ligament
Umbilical arteries
medial umbilical ligaments
ductus arteriosus
ligamentum arteriosum
ductus venosus
ligamentum venosum
foramen ovale
fossa ovalis
allantois
urachus-median umbilical ligament; the urachus is part of the allantoic duct between the bladder and the umbilicus. Urachal cyst or sinus is a remnant.
Notochord
Nucleus pulposus of intervertebral disc
SA and AV nodes are supplied by…
Right coronary artery (RCA)
Right dominant circulation
85%; posterior descending artery (PD) arises from RCA