Cardiology - Embryo and Anatomy

gazuwofu's version from 2017-05-10 19:12


Embryonic structureGives rise to
Truncus arteriosus (TA)Spirals up to yield ascending aorta and pulmonary trunk
Bulbus cordisSmooth parts (outflow tract) of left and right ventricles
PRimitive ventricleTrabeculated left and right ventricles
Primitive atriaTrabeculated left and right atria
Left horn of sinus venosusCoronary sinus
Right horn of sinus venosusSmooth part of right atrium
Right common cardinal vein and right anterior cardinal veinSVC
Interventricular septum development (steps)1. Muscular ventricular septum forms
2. AP septum rotates and fuses with muscular ventricular septum to form membranous interventricular septum, closing the interventricular foramen
3. Growth of endocardial cushions separates atria from ventricles; contributes to atrial separation and membranous portion of interventricular septum
Interatrial septum development
1. Foramen primum narrows as septum primum grows toward endocardial cushions
2. Perforations in septum primum form foramen secundum (primum disappears)
3. R→L shunt through secundum as septum secundum begins to grow
4. Foramen ovale is permanently formed in septum secundum
5. Septum secundum grows and with septum primum completely block off any openings
6. Remaining portion of septum primum is nothing more than the valve over the closed foramen ovale
Fetal erythropoiesis occurs where?"Young Liver Synthesizes Blood"
Yolk sac (3-10 wk)
Liver (6 wk-birth)
Spleen (15-30 wk)
Bone marrow (22 wk - adult)
Fetal hemoglobinalpha2gamma2
Adult hemoglobinalpha2beta2
PO2 of umbilical vein vs. arteryvein=30 mmHg (80% SaO2)
Shunt to bypass hepatic circulationDuctus venosus
Umbilical vein → IVC
Shunt to bypass lungsforamen ovale
Shunt to catch the rest of the blood that the foramen ovale misses and avoid the lungsDuctus arteriosus
Pulmonary artery→Descending aorta
What closes PDA? Opens it?Indomethacin closes PDA
Prostaglandins E1 and E2 keep it open
Umbilical vein becomesLegamentum teres hepatis
(Contained in falciform ligament)
Umbilical arteries becomeMedial umbilical ligaments
Ductus arteriosus becomesLigamentum arteriosum
Ductus venosus becomesLigamentum venosum
Foramen ovale becomesFossa ovalis
Allantois becomesUrachus-median umbilical ligament
(Urachus=part of allantoic duct from bladder to umbilicus)
Notochord becomesNucleus pulposus of intervertebral disc


Question Answer
Right-dominant circulation and posterior descending artery (PD)85% - PD arises from right coronary artery
Left dominant circulation8% - PD arises from Left circumflex artery
Codominant circulation7% - PD arises from both left circumflex artery and RCA
Coronary artery occlusion most commonly occurs in theLAD
When do coronary arteries fill?Diastole
Most posterior part of heartLeft atrium
Enlargement of the most posterior part of the heart can causedysphagia (compression of esophagus)
hoarseness (compression of left recurrent laryngeal nerve - a vagus branch)