Shelf: Thorax Embryo Flashcards
primitive ventricle
enlarges and folds over to form the base and left margin fo the heart
septum primum
crescent shape membrane that grows from the roof of the primitive atrium toward the endocardial cushions
foramen primum
space below septum primum that allows right and left atria to communicate
foramen secundum
forms in the center of the septum primum
foramen ovale
opening between upper and lower limbs of septum secundum
How is functional closure of the foramen ovale achieved
decrease in right atrial pressure and increase in left atrial pressure forces the septum primum against the septum secundum to close the foramen ovale
End state of septum primum & secundum
they fuse to complete the formation of the atrial septum
patent foramen ovale
what is it
symptoms
allows a continuation of atrial blood shunting
symptoms: asymptomatic
What causes patent foramen ovale?
abnormal reabsorption of the septum primum during the formation of the septum secundum
premature closure of foramen ovale
closure of the foramen ovale during prenatal life; results in hypertrophy of the right side of the heart and underdevelopment of the left side of the heart
membranous vsd
cause
result
associated with
cause: faulty fusion of right and left bulbar ridge, AV cushions
result: opening b/w right and left ventricles that allows free flow of blood (shunting of blood, left to right or right to left)
left to right shunting of blood
symptoms
pulmonary hypertension, increased pulmonary blood floor
right to left shunting of blood
symptoms
cyanotic baby at birth
prenatal shunt type
right to left shunt
heart development begins in what week
week 4
muscular IV
develops in midline of floor of primitive ventricle and grows toward AV cushions
IV foramen is closed by
membranous IV septum
membranous AV septum components
right bulbar ridge
left bulbar ridge
AV cushions
VSD’s normally occur in
membranous interventricular septum
aorticopulmonary septum
spiral septum formed as the truncal ridges grow, spiral and fuse
aortic arch 3 gives rise to
R & L common carotid A’s
R and L internal carotid A’s
aortic arch 4 gives rise to
right subclavian artery
arch of the aorta
aortic arch 6 gives rise to
L and R pulmonary arteries
ductus arteriosus
persistent truncus arteriosus
characterized by
what happens?
outcomes
characterized by a ventricular septal defect, single truncal valvae & common ventricular outflow
happens: systemic venous blood & pulmonary venous blood mix and desaturated blood is ejected into the single outflow tract
outcome: without surgical intervention, death in infancy
