Cardiovascular Flashcards
Where do the following heart structures come from?
- Ascending aorta and pulmonary trunk
- smooth parts of left and right ventricles
- trabeculated left and right ventricles
- trabeculated left and right atria
- coronary sinus
- smooth part of right atrium
- SVC
- Truncus arteriosus –> ascending aorta and pulmonary trunk
- Bulbus cordis –> smooth part of left and right ventricles
- Primitive ventricle –> trabeculated L and R ventricle
- Primitive atria –> trabeculated L and R atria
- Left horn of sinus venosus –> coronary sinus
- Right horn of sinus venosus –> smooth parts of right atrium
- Right common cardinal vein and right anterior cardinal vein –> SVC
How does the ascending aorta and pulmonary trunk form?
Neural crest migrates to form the truncal and bulbar ridges that spiral and fuse to form the aorticopulmonary septum
What forms due to failure of the AP septum to spiral?
Transposition of great vessels
What happens when you have a skewed AP septum?
tetraology of Fallot
What happens when you have a partial AP septum development?
persistent Truncus arteriosus
What are the steps for IV septum development of the heart?
- muscular ventricular septum forms. opening is called the interventricular foramen
- AP septum rotates and fuses w/ muscular ventricular septum to form membranous interventricular septum closing the foramen
- Growth of endocardial cushions separates atria from ventricles and contributes to both atrial separation and membranous portion of the IV septum
What are the steps for interatrial septum development?
- foramen primum narrows as septum primum grows toward endocardial cushion
- Perforations in septum primum form foramen secundum (foramen primum disappears)
- Foramen secundum maintains R to L shunt as septum secundum begins to grow
- Septum secundum contains a permanent opening (foramen ovale)
- Foramen secundum enlarges and upper part of septum primum degenerates
- Remaining portions of septum primum forms valve of foramen ovale
- Septum secundum and septum primum fuse to form the atrial septum
- Foramen ovale usually closes soon after birth b/c of increased LA pressure
Where does fetal erythropoiesis occur?
Yolk sac - 3- 10 wks Liver - 6 wk to birth Spleen - 15 to 30 wks Bone marrow - 22 wk to adult * Young liver synthesis blood
What fetal vessels have more oxygentaed blood?
- umbilical vein is 80% saturated w/ O2 and a PO2 of 30 mmHg
What is the flow of blood in a fetus?
- umbilical vein from placenta carries oxygenated blood to Ductus Venosus into the IVC to bypass the hepatic circulation
- Most oxygenated blood reaching the heart via the IVC is diverted thru the foramen ovale and pumped out the aorta to the head and body
- Deoxygenated blood entering the RA from the SVC enters the RV, is expelled into the pulmonary arteries and then passes thru the ductus arteriosus into the descending aorta.
What happens when an infant takes its first breath?
- decreased resistance in pulmonary vasculature b/c of decreased intrathoracic pressure = increased left atrial pressure vs right atria pressure
- foramen ovale closes
- increase in O2 leads to decreased in PGs causing closure of ductus arteriosus
What can help close the Patent ductus arteriosus?
Indomethacin - blocks PGs
What helps keep PDA open?
PG E1 and E2
What are the remnants of the following fetal-postnatal derivatives?
- umbilical vein
- umbilical arteries
- ductus arteriosus
- ductus venosus
- foramen ovale
- allantois
- notochord
- umbilical vein –> ligamentum teres hepatis (contained in falciform ligament)
- umbilical artery –> medial umbilical ligament
- ductus arteriosus –> ligamentum arteriosum
- ducuts venosus –> ligamentum venosum
- foramen ovale –> fossa ovalis
- allantois –> urachus-medial umbilical ligament
- notochord –> nucleus pulposus of IV disc
What artery supplies the SA and AV nodes?
RCA