Embryology anatomy Flashcards
What are the four major stages in heart development?
Stage 1: primitive heart tube
Stage 2: HEart looping
Stage 3: Atrial and ventricular septation
Stage 4: outflow tract septation
What froms the circulatory system in the 3rd week?
Lateral plate splanchnic mesoderm
Where does each horn get its venous blood from?
yolk sac (=vitelline v.)
placenta (=umbilical v.)
body of the embryo (=common cardinal v.)
What froms a U-shaped bulboventricular loop?
Bulbus cordis and ventricle grow faster than other regions forming a U-shaped
bulboventricular loop
Where does the heart tube loop in dextrocardia?
To left thsi comign to lie facing the right
What masses of tissues forming does the partitioning of primordial heart involve?
Endocardial cushion formation
Septum formation
What does the endocardial cushion formation seperate?
separates right atrium + ventricle from
left atrium +ventricle to form L&R AV canal
What does the septum formation seperate?
– separates right atrium from left atrium
+ right ventricle from left ventricle
How is the ostium secundum formed?
By formation of septum primum stretching down to the endocardial cushions
What does non closure result in?
Atrial septal defect
What does the aorticopulmonary septum divide?
BC and TA into aorta and pulmonary trunk
Where does the Av node and bundle develop from?
Cells of thr AV canal and sinus venosus
Whats the cause of transposition of great vessels?
Cause - 1) Failure of aorticopulmonary septum to take a spiral course
- 2) Defective migration of neural crest cells
What is the cause of tetralogy of fallout?
Cause – Unequal division of
the conus due to anterior
displacement of aorticopulmonary
septum
