Embryology Flashcards
What forms the smooth muscle in the blood and lymphatic vessels?
The Somatic (Parietal) mesoderm
What forms the smooth muscle surrounding the primitive gut derivatives?
The Splanchnic (Visceral) mesoderm
What does the Intraembryonic mesoderm give rise to?
The Pleural Cavities and the Pericardial cavity
What does the splanchnic mesoderm give rise to?
The Cardiac muscle
What are the 5 structures of the primitive heart?
The Truncus Arteriosus, the Bulbus Cordis, the Ventricle, the Atrium and the Sinus Venosus
What does the Truncus Arteriosus give rise to?
The Aorta and the Pulmonary Trunk
How does blood flow through the primitive heart?
Sinus Venosus > Primitive Atrium > Primitive Ventricle > Truncus Arteriosus
What veins enter the heart caudally in the embryonic stage?
The Vitelline Vein, the Umbilical Vein and the Common Cardinal Vein
What do the caudal veins form?
The Superior and Inferior Vena Cava
What separates the trabecular and smooth portions of the atria?
The Crista Terminalis
What does the Sinus Venosus form?
The smooth wall of the right atrium
What does the Atrioventricular septum separate?
The Right Atrium and the Left Ventricle
What causes the intertatrial septation?
The Septum Primum and the Septum Secundum
What is the function of the oval foramen?
It allows blood to bypass the non functional lungs
What does the oval foramen become after birth?
The fossa ovalis
What is the source of oxygenated blood in the embryonic stage?
The Placenta
What is the function of the Ductus Arteriosus?
It allows the blood from the pulmonary artery to enter the aorta and bypass the lungs
What does the Umbilical Vein form after birth?
The Ligamentum Teres
What does the Ductus Venosus form after birth?
The Ligamentum Venosum
What happens if there is an Ostium Premium Defect?
The ostium primum doesn’t close
What is the result of an ostium primum defect?
Nothing
What happens if there is an ostium secundum defect?
The ostium secundum doesn’t close
What is the interventricular septum formed by?
The Muscular Septum and the Membranous Septum
What is required for correct ventricular septation?
Spiral septation and a division of vessels equal in length
Are Ventricular Septal Defects acyanotic?
Yes, blood re-enters the pulmonary circulation
What causes the Tetralogy of Fallot?
The unequal division of the truncus anteriosus
What is Persistent Truncus Arteriosus?
The truncus arteriosus fails to properly divide
What is the result of Persistent Truncus Arteriosus?
Blood gets mixed as it exits the heart as one common ventricular outlaw tract by both sides
What is Transposition of the Great Arteries?
The Truncus Arteriosus is not spiraled
What is the result of Transposition of the Great Arteries
Deoxygenated blood enters circulation while oxygenated blood enters the lungs as the two main arteries carrying blood out of the heart are inversely positioned
What is Patent Ductus Arteriosus
The Ductus Arteriosus fails to obliterate post-birth
What is the result of Patent Ductus Artreriousus?
Blood gets mixed as it exits the heart
What is Aortic Stenosis?
It is a narrowing of the left ventricle of the heart
What is the result of Aortic Stenosis?
There is an increase in pressure within the heart to pump blood across a smaller opening
