Steve Colbert's Cardiac Comedy Clues Flashcards
(298 cards)
What does this embryonic structure grow into: Truncus arteriosus
Ascending aorta and pulmonary trunk
What does this embryonic structure grow into: Bulbus cordis
Smooth parts (outflow tract) of left and right ventricles
What does this embryonic structure grow into: Primitive atria
Trabeculated part of left and right atria
What does this embryonic structure grow into: Primitive ventricle
Trabeculated part of left and right ventricles
What does this embryonic structure grow into: Primitive pulmonary vein
smooth part of left atrium
What does this embryonic structure grow into: Left horn of sinus venosus (SV)
Coronary sinus
What does this embryonic structure grow into: right horn of SV
smooth part of right atrium
What does this embryonic structure grow into: Right common cardinal vein and right anterior cardinal vein
SVC
Heart embryo morphogenesis
first functional organ to develop in vertebrate embryos; beats spontaneously by 4th week
Cardiac looping in embryo
primary heart tube loops to establish left-right polarity; begins in week 4 of gestation; defect in left right dynein (involved in R/L asymmetry) can lead to dextrocardia, as seen in Kartagener syndrome (primary ciliary dyskinesia)
Walk through the steps of the separation of the heart chambers in embryo
1) Septum primum grows toward endocardial cushions, narrowing foramen primum; 2) Foramen secundum forms in septim primum (foramen primum disappears); 3) Septim secundum maintains R to L shunt; 4) Septum secundum expands and covers most of the foramen secundum. THe residual Foramen is the foramen ovale; 5) Remaining portion of septum primum forms valve of foramen ovale; 6) Septum secundum and septum primum fuse to form the atrial septum; 7) formane ovale usually closes soon after birth because of increase LA pressure.
Patent foramen ovale
caused by failure of septum primum and septum secundum to fuse after birth; most are left untreated; can lead to paradoxical emboli (venous thromboemboli that enter systemic arterial circulation), similar to those resulting from an ASD
Walk through the steps of ventricle formation in ventricles
1) muscular ventricles septum forms. Opening is called interventricular foramen. 2) Aorticopulmonary septim rotates and fuses with muscular ventricular septum to form membranous interventricular septum, closing interventricular setpum. 3) Growth of endocardial cushions separates atria from ventricles and contributes to both atrial septation and membranous portion of the interventricular septum.
Ventricular septal defect (VSD)
most commonly occurs in the membranous septum; acyanotic at birth due to L to R shunt
Outflow tract formation in embryo
Truncus arteriosus rotates; neural crest and endocardial cell migrations leading to truncal and bulbar ridges that spiral and fuse to form aorticopulmonary septum leading to the ascending aorta and pulmonary trunk
Conotruncal abnormalities
Transposition of great vessels; Tetralogy of fallot; Persistent truncus arteriosus
Valve development: Aortic/pulmonary
derived from endocardial cushions of outflow tract
Valve development: Mitral/tricuspid
Derived from fused endocardial cushions of the AV canal
Ebstein anomlay
Displaced valves from abnormal development
Fetal erythropoiesis
Yolk sac (3 to 8 weeks); Liver (6 weeks to brith); Spleen (10-28 weeks); Bone marrow (18 weeks to adult); “Young Liver Synthesizes Blood”
Hemoglobin development
Fetal hemoglobin=HbF (alpha2Gamma2);
Adult hemoglobin=HbA (alpha2beta2);
HbF has higher O2 affinity for oxygen due to less avid binding of 2,3 BPG;
Fetal circulation;
Blood entering fetus through the umbilical vein is conducted via the ductus venous into the IVC to bypass the hepatic circulation; Oxygenated Blood from IVC goes through heart and is shunted through foramen ovale; Deoxygenated blood entering the RA from the SVC goes into the RA into the RV into the main PA into the patent ductus arteriousus into the descending aorta
At birth the infant takes its first breath then:
the resistance in pulmonary vasculature decreases leading to an increase in left atrial pressure vs right atrial pressure; foramen ovale closes (now called fossa ovalis; increase in O2 (from respiration) and decrease in PGE (from placental separation) leads to closure of ductus arteriosus
fetal-postnatal derivatives: umbilical vein turns into
ligamentum teres hepatis; contained in falciform ligament