Embryology Flashcards
What is the fist organ to complete its development in fetal growth?
The heart
In 23 days a ____ is formed
Single heart tube
In 43 days a ____ is formed
A complete heart
Starting from the bottom of a embryologic heart tube name the structures and what they form.
• Sinus venous: 3 cardiac veins, cardinal, umbilical, viteline veins. This ends up forming the IVC, SVC, pulmonic veins, CS, and posterior parts of RA & LA
•Primitive atrium: becomes left & right atrium
• primitive ventricle: becomes LV
• bulbous cordis: becomes RV, and left and right outflow tracks
• Truncus arterious: forms aorta, pulmonic artery,
When does the truncus arteriosus divide
31st day
What anomaly occurs when the truncus doesn’t divide?
Truncus arteriousus (conotruncal division)
What is conotruncal division?
The correct division of the heart tube
What anomaly might occur during the looping phase?
L Looping
What is transposition of the great arteries?
Where are the great arteries the aorta and pulmonic artery are switched. Essentially blood is flowing through two different circuits in the heart never intermixing.
This causes oxygenated blood to go through the pulmonary artery to the lungs and then stay on the left side
While deoxygenated blood goes to the aorta out to the body and never reaches the lungs for mixing
Is transposition of the great arteries an issue if the fetus is still in the womb?
No. Because during this time the fetus is not using the lungs it is instead getting oxygenated blood from the mother.
AND -there are a few open shunts during fetal development that remain open and allows some oxygenated blood to go through the heart and out to the body
There are a few open shunts during fetal development that remain open and allows some oxygenated blood to go through the heart and out to the body. What are they ?
PDA- pulmonic artery and aorta connection
PFO- open shunt within the IAS
Ductus venosus
Once the fetus is born, what occurs with de transposition of the great arteries?
Once the fetus is born, it then has to use its lungs and all of those shunts begin to close. The
issue with this is the fetus longer longer has shunts to carry oxygenated blood so now you have a baby that has 2 separate blood circuits & no oxygenated blood going out to the body, and this leads to death.
D transposition means?
L transposition means?
D-transposition means death, unless you have a shunt open to help carry oxygenated blood
L- Transposition means you live and is the correct way for blood to circle through the heart
What is the current surgery of choice for a TGA?
Great arterial switch
What is the biggest symptom seen with TGA?
Cyanosis
What is acyanotic TGA?
Where the aorta and pulmonic artery are connected to the wrong ventricle, however the correct blood flow still makes it out
What is another name for acyanotic TGA?
Levo TGA
Although Levo TGA is considered congenitally corrected TGA and is not life-threatening what is another issue that can occur down the road?
Because the ventricles are switched along with their valves, it is now the right ventricle getting high pressures and the left ventricle getting low pressures and this can affect valve function and hemodynamic compromise
In dextro TGA what occurs
The aorta and the pulmonic artery are switched. Aorta is connected to the RV pulmonic arteries connected to LV.
So there is no oxygenation of blood getting out to the body unless the fetus is in the womb and has shunts.
What does the sinus venosus turn into?
SVC, IVC, coronary sinus,posterior portions of both atrium and the pulmonary veins
What does the primitive atrium compose of?
Primitive, right atrium and left atrium
What does the primitive ventricle compose of?
Primitive left ventricle
What does the bulbus cordis compose of?
The right ventricle and the left and right outflow tracks
What does the truncus arteriosus composed of/become?
The aorta and pulmonic artery
It also becomes the carotid arteries and descending aorta
