Aldridge - Development Of Heart Flashcards
Early development of heart begins day 18 in cardiogenic ____________
Splanchnic mesoderm
Paired endocardial heart tubes form from ________ in cardiogenic area
Splanchnic mesoderm
Paired endocardial heart tubes are brought together due to ________ and fuse in midline to form a single heart tube which forms the definitive endocardium.
Lateral folding`
_________ surroundin the heart tub will form myocardium
Splanchnic mesoderm
Aortic arches originate from the rostral end of _________
Truncus arteriosus
Sinus venosus receives blood from the
Paired umbilical veins
Paired vitelline veins
Paired common cardinal veins
_______ supply pharyngeal arches w/ blood
Aortic arches
Future central tendon of diaphragm
Septum transversum
Fixation of the ends of the heart tube causes the rapidly elongating heart tube to fold ____ and to the _______
Ventrally and to the right
So atrium and sinus venosus lie dorsal to the primitive ventricle and bulbis cordis
The dorsal and ventral endocardial cushions fuse together to form the fused endocardial cushions, which divides the atrioventricular canal into ___- and _____ AV canals
Right and left
The opening between the lower edge of the septum secundum and the upper edge of the lower part of the septum primum
Is a passageway for oxygenated blood from the placenta entering the right atrium to be shunted to left atrium
Provides shunt for much of O2’d blood to go directly into the arterial system of the fetus and by pass the nonfunctional developing lungs
Foramen ovale
After birth, the foramen ovale is functionally closed to form the fossa ovalis by ?
Decrease in right atrial pressure due to the shut down of the placental venous return
The increase in left atrial pressure due to greater amount of pulm venous blood returning to the heart
The floor of the fossa ovalis is formed by the ?
Lower part of the septum primum
The limbus (anulus, rim) of the fossa ovalis is formed by the
Lower border of the septum secundum
The part of the atrium with rough walls (musculi pectinate) is formed by the ?
Primitive atrium
The part of the atrium that is smooth walled, is formed from the ?
Sinus venosus
The right horn of the sinus venosus is incorporated into the
Definitive right atrium ( forms smooth walled part [sinus venarum])
The left horn of the sinus venous forms the ?
Coronary sinus
The _________ is incorporated into the definitive left atrium to form its smooth part
Pulmonary vein
The primitive left ventricle forms only the _______
Definitive left auricle
Pairs of bulbar ridges and truncal ridges grow longitudinally down the bulbus cordis and truncus arteriosus. These ridges are formed by ___________
Neural crest cells
The bulbar and truncal ridges fuse to form the _________
Aorticopulmonary septum
Divides bulbus cordis and truncus arteriosus into ascending aorta and pulmonary trunk
Forms in the midline of the floor of the ventricle and grows towards the atrioventricular septum
Muscular ventricular septuum
Located between the atrioventricular septum and the free edge of the muscular ventricular septum
Interventricular foramen
Closes the interventricular foramen
Formed by the fusion of the atrioventricular septum, left bulbar ridge, and right bulbar ridge (of bulbus cordis)
Membranous ventricular septum
Components of the definitive right ventricle :
A. The trabeculated part formed from the ________
B. The smooth upper part, the conus arteriosus, is formed from the ____________
Primitive ventricle
Bulbus cordis
Components of the definitive left ventricle
A. The trabeculated part, formed from the ______
B. The smooth upper part; (aortic vestibule), is derived from the bulbus cordis.
Primitive ventricle
Large opening between the right and left atria
Results from excessive resorption of the septum primum, or insufficient development of septum secundum
Most common and clinically important ASD
Blood flows from left atrium to right atrium due to higher BP in left atrium postnatally
Foramen secundum defect
Type of ASD
Found in 25% of population
Not pathological (no blood shunting)
Is an incomplete anatomical fusion of septum primum and septum secundum
Probe-patent foramen ovale
ASD
Total absence of development of atrial septum
Common atrium
Conotruncal abnormalities associated with failure of neural crest cells to migrate
Transposition of great vessels
Tetralogy of Fallot
Persistent truncus arteriosus
ASD
Foramen ovale closed prenatally
Results in hypertrophy of right side of heart and underdevelopment of the left side of the heart
Premature closure of the foramen ovale
Defect of endocardial cushions;
Failure of endocardial cushions to fuse; defects in atrial and ventricular septum resulting in single atrioventricular orific
Persistent atrioventricular canal
Defect in endocardial cushion
Partial fusion in endocardial cushion resulting in a gap in the inferior part of the atrial septum.
Ventricular septum intact.
Endocardial cushions partially fuse to form membranous part of interventricular septum, but do not fuse enough to join septum primum
Foramen primum defect
Overall most common form of congenital cardiac abnormality
Ventricular septum defect
These usually occur in the membranous part
Most common VSD, results from the failure of proper fusion of the three structures that form the membranous interventricular septum. Blood flows from Left ventricle to right ventricle.
Membranous interventricular septal defect
The “5 T’s of early cyanosis”
Right to left shunts
Truncus arteriosus
Transposition of great vessles
Tricuspid atresia
Tetralogy of fallot
TAPVR
Abnormal divisions of the truncus arteriosus is due to ?
Abnormal migration of neural crest cells into bulbar and truncal ridges
Aorta originates from right ventricle and pulm A originates from Lt ventricle
Failure of aorticopulmonary septum to spiral w/in the bulbus cordis and truncus arteriosus
Assoc’d w/ ASD, patent ductus arteriosus, and VSD
Infanct will present w/ marked cyanosis which is fatal unless surgical reparation
Transposition of the Great Arteries
Failure to develop bulbar and truncal ridges
Presents as single artery giving rise to both pulm trunk and ascending arota
Usually accompanied w/ defect in interventricular septum (nobulbar ridge to fuse w/ atrioventricular septum)
Marked cyanosis
Persistent truncus arteriosus
Absence of tricuspid valve and hypoplastic right ventricle.
Requires both ASD and VSD for viability
Cyanosis
Tricuspid atresia
Abnormal neural crest cell migration into truncal ridges
Aorticopulmonary septum skewed to one side of truncus arteriosus
Enlargement of either ascending aorta or pulmonary trunk w/ reduction in other vessel
Skewed Aorticopulmonary septum does not align w/ interventricular septum, resulting in ASD.
Can have pulmonary atresia
Unequal division of the truncus arteriosus
Interventricular septal defect
Hypertrophy of right ventricle
Over-riding aorta; large aorta overrides interventricular septal defect
Pulmonary stenosis
Due to unequal division of bulbus cordis.
Marked cyanosis
Tetralogy of Fallot
Heart located on the right side of thorax
Due to ventricles and bulbus cordis bending to the wrong side
Relatively uncommon
Dextrocardia
Dextrocardia with the inversion of other viscera
Dextrocardia with situs inversus
