Basic Cardiac Embryology Flashcards
The fully-functional, 4-chamber, two-pump heart starts out as a …
pair of endocardial tubes
Name the 4 main steps of heart development
- Fusion of the L/R endocardial tubes into a primary heart tube
- Folding/looping of the heart tube on itself
- Septation (partitioning)
- Remodeling of the venous pole
Heart tissues arise from…
splanchnic mesoderm in the head area in the cardiogenic zone
Lateral and cranial folding leads to midline fusion of…
the two endocardial tubes into the primitive heart tube
By 21-22 days, the pimitive heart tube has become a structure divided into 4 chambers called..
- truncus arteriosus
- bulbus cordis
- primitive ventricle
- primitive atrium
The bulbus cordis and primitive ventricle fold towards the…
right, making a C-shape
The bulbus cordis and primitive ventricle form the … end
cranial end
The primitive atrium forms the … end
caudal end
The primtive atrium forms an … shape
S shape
At what point does the heart take on a more recognizable shape? Describe it
Day 28
- primitive ventricle is ventral and more caudal
- primitive atrium is more dorsal and cranial
- arterial outflow points cranially
What forms the basis of many types of congenital heart defects?
Abnormal septation
Describe atrial septal defects
Failure of atrial septa to develop properly.
For example, the septum secundum may fail overlap the foramen secundum.
(LA to RA shunt)
Describe ventricular septal defects
Failure of muscular or membranous IV septum to form properly
(LV to RV shunt)
What is an aorticopulmonary septum defect?
Uneven septation of the truncus arteriosus by the conotruncal ridges, causing stenosis of the pulmonary trunk or aorta
What is a tetralogy of Fallot?
What are the 4 symptoms?
When several septation defects happen simultaneously.
* ventricular septal defect
* pulmonary valve and trunk stenosis
* overriding aorta (R to L shunt)
* hypertrophy of the right ventricle (due to stenosis)
