Great Vessel Development Flashcards
what do intersegmental arteries arise from?
vasculogenesis
what are the cervical intersegmental arteries united by longitudinally?
vertebral artery
what happens to the roots of the 1-6 cervical intersegmental arteries?
they are loss
what does the 7th intersegmental artery on the left form?
the left subclavian artery
what are the thoracic intersegmental arteries united by?
the internal thoracic artery
what happens to the intersegmental arteries that are united by the internal thoracic artery?
they become the intercostal arteries
what is the aortic sac?
an expansion at the distal most portion on the truncus arteriosis
What happens to the 3rd AA on both sides?
it will become the common carotid artery and the proximal portion of the internal carotid artery
where does the external carotid artery come from?
it branches off of the 3rd AA
where does the distal part of the internal carotid come from?
the dorsal aorta
what happens to the left 4th AA?
it will form part of the aortic arch in the newborn
what are the parts of the aortic arch?
the 1st part is formed by the aortic sac, the 2nd part is formed by the 4th AA, the 3rd and 4th parts are formed from the dorsal aorta (proximal and distal to the 7th intersegmental artery
what happens to the right 4th AA?
it will form the proximal part of the right subclavian artery
what all forms the right subclavian artery?
the right 7th intersegmental artery forms the distal portion, the right 4th AA forms the proximal portion, and the dorsal aorta forms the rest of the right subclavian artery
what happens to the right 6th AA?
there is regression of the distal part- and there is loss of connection to the distal aorta
what is the position of the right recurrent laryngeal nerve?
it becomes hooked around the right subclavian artery
what happens to the left 6th AA?
the connection to the dorsal aorta is retained and it becomes the ductus arteriosus
what is the position of the left recurrent laryngeal nerve?
it will be hooked around the ductus arteriosus- aka the future ligamentum arteriosum
what happens to the dorsal aorta between the 3rd and 4th AAs?
it is loss
what happens to the dorsal aorta on the right after the 7th intersegmental artery?
it is loss all the way up to the junction between the left dorsal aorta
what does the umbilical vein carry?
oxygenated blood back to the fetal heart from the placenta
why does the oxygen-rich blood in the umbilical artery bypass the liver and go straight for the IVC?
the fetal liver doesn’t have to do a lot of filtering so it uses the ductus venosum to bypass the liver
what happens to the bulk of the blood that enters the RA from the IVC?
it passes through the foramen ovale into the LA
what happens to most of the blood that enters the heart through the SVC?
it is directed to the RV
what happens to about 90% of the blood that is in the RV?
it enters the descending aorta via the ductus arteriosus
in the fetus, what keeps the ductus arteriosus open prior to birth?
prostaglandins
what causes the closure of the ductus arteriosus?
changes in blood oxygen tension, a sudden drop of prostaglandins, and an increase in endothelin
what happens if you have a patent ductus arteriosus?
1/3 of the blood traveling via the aorta will enter the pulmonary artery because the systemic blood pressure is higher
what effect does a patent ductus arteriosus have on the heart?
there will be LV hypertrophy and eventual CHF
when might there be an increased risk of a patent ductus arteriosus?
with maternal rubella infection during early pregnancy
what is coarctation of the aorta?
the aortic lumen below the origin of the left subclavian is narrowed
what are the two different types of coarctation of the aorta?
postductal and preductal
what is postductal coarctation and what occurs with it?
it is coarctation that occurs after the ductus arteriosus- collateral circulation is established and it is not as severe
what is preductal coarctation and what occurs with it?
it is coarctation othat occurs before the ductus arteriosus- collaterals do not form- little or no blood gets to the lower body unless ductus arteriosus remains open
what is aberrant origin of the right subclavian?
the right subclavian is formed by the distal portion of the right dorsal aorta and the 7th intersegmental artery- the right 4th AA and proximal part of the dorsal aorta are obliterated
what might an aberrant origin of the right subclavian cause?
dysphagia or dyspnea because the right dorsal aorta must cross the esophagus to reach the upper limb
what is a double aortic arch?
when the portion of the dorsal aorta between the right 7th intersegmental artery and distal dorsal aorta are retained
what is the effect of a double aortic arch?
strangulation of the trachea
what abnormality of the great arteries is Turner’s Syndrome associated with?
coarctation of the aorta
what occurs during an interrupted aortic arch?
both the right and the left 4th AA disappear
what great vessel abnormality is associated with DiGeorge syndrome?
interrupted aortic arch
as the liver develops, what veins form the hepatic sinusoids?
the vitelline veins
what does the proximal portion of the right vitelline vein form?
the right hepatocardiac channel
what happens to the proximal part of both sides of the umbilical veins?
they disappear
what is the only vein left to carry blood from the placenta to the liver?
the left umbilical vein
what allows most of the blood to bypass the sinusoidal plexus of the liver?
the ductus venosus
what is the early drainage system of the body?
the anterior and posterior cardinal vein
what do the anterior and posterior cardinal veins form when they join together?
the common cardinal vein
what does the anastomosis between the right and left anterior cardinal vein form?
the left brachiocephalic vein
what does the SVC form from?
the right common cardinal vein
what forms if you do not form an anastomosis between the right and left anterior cardinal vein?
a left superior vena cava draining into the coronary sinus
what forms if you have a right to left anastomosis of the anterior cardinal veins?
you will get a right brachiocephalic vein and a left superior vena cava
