Cardiology Flashcards
(56 cards)
In developing fetus, pressure in R heart > pressure in L heart. Why?
Lungs (and thus pulmonary circulation) are not fully functional. This creates increased vascular resistance in pulmonary arterial circulation, and increased pressure in R heart (which supplies pulmonary arterial circulation).
Fetal erythropoiesis occurs in which 4 sites?
Yolk sac (3-8 wks)Liver (6 wks - birth)Spleen (10-28 wks)Bone marrow (18 wks - adult)”Young Liver Synthesizes Blood”
Primary site for O2 exchange in fetus?
Chorionic villi (Umbilical vein is derived from villus vessels)
Chorionic villi is derived from ___ (maternal/fetal) tissue?
Fetal tissue
Fetal circulatory shunt:Ductus venosus = ?
Oxygenated blood conducted via umbilical vein bypasses liver (hepatic circulation) via ductus venosus directly into IVC, which drains into RA
RV - Right acute/marginal artery LV anterior wall - LAD (LCA) LV posterior wall - PDA LV lateral wall - LCX (LCA) LV inferior wall - RCA LV anteroseptal wall - proximal LAD (LCA) LV anterolateral wall - LCX (LCA)
Anterior 2/3 of IV septum - LAD (LCA)
Posterior 1/3 of IV septum - PDA
Anterior (anterolateral) papillary muscle in LV
- LAD (LCA)
Posterior (posteromedial) papillary muscle in LV - PDA
b
Right-dominant coronary circulation?
Left-dominant coronary circulation?
Co-dominant coronary circulation?
PDA arises from RCA (80%)
PDA arises from LCX branch of LCA (10%)
PDA arises from both RCA and LCX branch of LCA (10%)
In fetal circulation, most blood that enters RA via SVC is conducted where?
SVC –> RA –> RV –> pulmonary artery –> PDA –> descending aorta Blood is conducted/shunted through patent ductus arteriosus into aorta
During fetal development, what maintains patency of ductus arteriosus?
PGE2, a vasodilator synthesized by placenta
In fetal circulation, most blood that enters RA via IVC is conducted where?
IVC –> RA –> LA –> LV –> ascending aortaOxygenated blood from umbilical vein enters RA via IVC and is conducted/shunted through patent foramen ovale to LA. Oxygenated blood is most important to enter ascending aorta to provide blood with highest O2 tension to head/neck.
Why is blood conducted from RV shunted away from lungs and instead conducted through ductus arteriosus?
Low PaO2 –> chronic vasoconstriction of pulmonary arteries –> fetal pulmonary arteries are HYPERTROPHIED (high fetal pulmonary arterial resistance)When baby is born, 1st breath –> increases PaO2 –> decreases pulmonary arterial resistance
What 2 physiologic changes occur at birth that close ductus arteriosus?
1st breath –> increases PaO2Separation of placenta –> decreases PGE2
Describe physiologic changes that occur with 1st breath leading to closure of foramen ovale.
1st breath –> increases PaO2 –> decreases pulmonary arterial resistance –> blood flows through pulmonary circulation and drains into LA –> increases pressure in LA –> pressure LA > pressure RA –> functionally closes foramen ovale
Drug administered to close a patent ductus arteriosus?
Indomethacin
Drug administered to maintain a patent ductus arteriosus?
PGE2
EMBRYONIC STRUCTURE:Umbilical veinPost-natal derivative?
Ligamentum teres hepatis (within falciform ligament)
EMBRYONIC STRUCTURE:Umbilical arteriesPost-natal derivative?
Medial umbilical ligaments (Not to be confused with MEDIAN umbilical ligament, a derivative of urachus)
EMBRYONIC STRUCTURE:Ductus arteriosusPost-natal derivative?
Ligamentum arteriosum
EMBRYONIC STRUCTURE:Ductus venosusPost-natal derivative?
Ligamentum venosum
EMBRYONIC STRUCTURE:Foramen ovalePost-natal derivative?
Fossa ovalis
EMBRYONIC STRUCTURE:NotochordPost-natal derivative?
Nucleus polposus of IV disc
EMBRYONIC STRUCTURE:Urachus (allantois)Post-natal derivative?
Median umbilical ligament(Not to me confused with MEDIAL umbilical ligaments, derivatives of umbilical arteries)
Anterior surface of heart is formed by?
R ventricle
Another name for anterior surface of heart?
Sternocostal surface
