Heart tube, great vessels & atrial septation. Flashcards
myoblasts form in what part of the early embryo?
in the yolk sac
the myoblasts of the early embryo grow together to form what?
little vessels/tubes
which endocardial tubes fuse to become the heart tube?
the lateral endocardial tubes
describe the two structures pictured

the upper bulge = early ventricle
lower bulge = early atrium
does the heart grow at the same rate as the cavity it sits in?
no - it grows much faster - so it has to twist and turn on itself to continue development
describe the different regions of the primitive heart

what is it called when the apex is on the right side of the body?
Dextrocardia
what are the three major parts of the bulbus cordis?
trabeculated part of right ventricle
conus cordia
truncus arteriosus

what vein enters the primitive heart?
the Sinus venosus- right and left - enters the right primitive atrium and narrows
has ‘horn’s which recieve the vitelline vein, umbilical vein, and the common cardinal vein (anterior and posterior)
which veins vanish in heart embryology?
the right umbilical
left vitelline
which vein remains in the adult body behind the falciform ligament?
the left umbilical vein
what vein forms the connection between the two anterior cardinal veins?
blood flows from left to right = left brachiocephalic vein

where does the coronary sinus originate from from?
the left sinus horn
the anterior cardinal vein becomes…?
the right superior vena cava
what makes up the smooth/rough walls of the right atrium?
during atrial septation- where does the blood flow through?
throughout the development of atrial septation, the blood continues to flow from right to left
the septum primum (goes from roof of right atrium and divides the two parts of the chamber from eachother)
where does the septum secundum develop?
grows down in a sickle shape from the roof of the atrium - but it wont close all the way down to the endocardial cussion - the lower free edge= the foramen ovale

in the embryo, which side of the heart has higher pressure?
the right side - Note that in the adult, the left side has greater pressure
when does the atrial pressure switch from the right to the left?
when the baby takes its first breath - increases the pressure on the left side
what is it called when the septum primum doesnt properly anatomically fuse?
the patetn foramen ovale - usually asymptomatic -
if you have an atrial septal defect, where is the blood shunted?
from left to right b/c of difference in pressure - however, this ‘leaking’ of blood doesn’t change the oxygenation levels of blood
If partial pressure in oxygen isn’t changed from an atrial septal defect… what do we call it?
if it doesn’t change the oxygen level = acyanotic
what type of murmer would you have with an atrial septal defect?
Ejection systolic murmer -
