embryology heart development Flashcards
The germ layer named _______________ gives rise to the heart, arteries and veins .
mesoderm
The normal shunting of blood in the pre-natal heart moves blood from __________ atrium to ___________ atrium through holes named ______________________ .
right; left; ovale foramen and foramen secundum
The structure in the embryonic heart to which the interatrial and interventricular septa both attach is the _____________________________ .
endocardial cushion
The heart tube starts to beat during Week ____ of development.
4
The truncus arteriosus gives rise to two major arteries named ______________________ and _______________________ .
pulmonary trunk/arteries and aorta
Put this list of structures in the order in which blood flows through them:
Bulbus cordis, Atrium, Truncus arteriosus, Sinus venosus, Ventricle
Sinus venosus, Atrium, Ventricle, Bulbus cordis, Truncus arteriosus
Umbilical vein becomes the ______
Ligamentum teres
Foramen ovale becomes the ______
fossa ovalis
Umbilical arteries becomes the ______
Median umbilical ligament
Ductus arteriosum becomes the ______
Ligamentum arteriosum
Ductus venosus becomes the ______
Ligamentum venosum
Ductus arteriosus between _______ and _______ to bypass _________.
pulmonary artery; aorta; pulmonary circulation
Blood flows pulmonary artery → aorta (right–to left shunt
● Most Pulm. artery blood
passes → ductus (high
resistance in pulm arteries)
● Blood from ductus →
lower body.
explain the path of blood that enters through the superior vena cava
right atrium, right ventricle, pulmonary trunk, ductus arterious, lower body
explain the path of blood that enters through the inferior vena cava
right atrium, foramen ovale, left atrium, left ventricle, aorta, upper body regions
two main differences between prenatal and postnatal circulations
Prenatal: The fetus is attached to the vascular structure, the placenta, where gases, nutrients and wastes are exchanged with the maternal blood.
Prenatal: The fetus does not use its lungs for breathing, so they don’t need much blood.
The atrioventricular valves arise from the _______
endocardial cushion
The _____________ grows from floor to endocardial cushion, closing the Interventricular foramen.
Interventricular septum
Describe atrial subdivision
- Septum primum grows from roof to endocardial cushion. (1,2,3)
- Always need a hole. 1st is named Foramen primum.
It disappears. (2,3,4) - Holes form in the septum. (3)
- Coalesce to form 1 hole. Named Foramen secundum. (4)
- A second septum grows on the right side of the first,
from roof to endocardial cushion. Named Septum secundum. (5,6) - This septum has a hole, named Foramen ovale. This septum covers the Foramen secundum. (6)
The Septum primum is pushed to the left and acts
as an open valve of the _______.
Foramen ovale
during fetal development which atria has the greatest pressure
right causing blood to flow right to left
Final positions: ventricles located ______ and atria located more ______.
anteriorly; posteriorly
________ create blood cells. Later, blood cells arise in liver, spleen and bone marrow.
Vessel walls
heart development takes ____ weeks
5.5
Heart starts developing as a right and a left
blood vessel (called cords)
