Flashcards in Development of Arterial System Deck (34):
How are the dorsal aortae formed?
bilateral angiogenic cell clusters coalesce and form a pair of longitudinal vessels (the
What do the paired dorsal aortae become? How does this compare to the paired aortic
One aorta caudally. Paired aortic arches stay paired
Paired branchial arteries carry _______________.
Oxygenated blood to paired dorsal aortae
What gives off an arterial branch to each pharyngeal pouch?
Aortic sac (most distal part of the truncus arteriosus)
The aortic sac forms right and left horns as the truncus arteriosus divides into the
outflow tracts of the heart. What do the right and left horn become?
Right horn: brachiocephalic artery, Left horn: Proximal aortic arch
How is the development of the aortic arches related to development of somites?
The sequence of development of the aortic arches can help depict age
The branches from the aortic sac to the pharyngeal pouches are called _______. What
are they associated with ventrally and dorsally?
Aortic arches. Ventrally associated with aortic sac, Dorsally associated with dorsal
In what sequence are the aortic arches formed?
Craniocaudal sequence, creating a “basket” of arteries around pharynx
What do the 1st aortic arches become?
Small portion persists to become the maxillary artery
What do the 2nd aortic arches become?
Small portions persist to become the hyoid and stapedial arteries
What do the 3rd aortic arches become?
Become the common and proximal internal carotid arteries. Dorsal internal carotid
from dorsal aorta, external carotids branch from internal carotid
Arches IV and VI undergo asymmetric remodeling. What do the left part and the right
part of the 4th aortic arch become?
Left: part of the arch of the aorta (btn. Carotid and sublcavian arteries). Right: most
proximal portion of subclavian artery
From which artery does the 7th intersegmental artery branch from?
Right subclavian artery
If the right dorsal aorta fails to obliterate, what anomaly do we have? What should it
Double aortic arch (vascular ring). The right dorsal aorta should have disconnected
from fused midline dorsal aorta and the right 6th arch.
Abnormal obliteration of the R 4th arch and abnormal origin of the R subclavian artery
results in what?
Abnormal R subclavian crosses posterior to esophagus
What is the final right subclavian from?
(1) R 4th aortic arch (2) R dorsal aorta (3) R 7th segmental artery
What is the final aortic arch from?
(1) Truncus (2) L 4th aortic arch (3) L dorsal aorta
What is the final left subclavian from?
(1) L 7th segmental artery
What does the 5th aortic arch form?
The 5th aortic arch never forms or disappears quickly
What do the 6th aortic arches form?
R: proximal right pulmonary artery, L: ductus arteriosus
Summarize what aortic arches 1-6 form.
1 – maxillary artery, 2 – hyoid and stapedial arteries, 3 – carotids, 4- L: aortic arch, R:
subclavian artery, 5 – never forms!, 6 – L: ductus arteriosus, R: prox R pulmonary artery
Why are the recurrent laryngeal nerves different on the right and left sides?
R: distal 6th aortic arch disappears – nerve moves cranially – loops around subclavian.
L: 6th aortic arch persists as ductus arteriosus – nerve loops around ductus arteriosus. This
happens since the nerves have to loop back up to innervate the larynx
What are the three groups of arteries coming off the abdominal aorta?
Lateral branches (adrenal, renal, gonadal), body wall (intercostal, lumbar, extremities),
anterior branches (celiac, superior mesenteric, inferior mesenteric)
The vitelline arteries fuse and form the arteries in the dorsal mesentery of the gut.
Which artery forms the foregut, which forms the midgut, and which forms the hindgut?
Celialc artery (foregut), superior mesenteric artery (midgut), inferior mesenteric artery
Because _______ , the path out of the RV is through the ductus arteriosus into the
pulmonary artery resistance is high
The umbilical vein is ____% saturated. It heads from the placenta into the fetus through
80% saturated. Towards liver – ductus venosus – IVC – RA – foramen ovale – LA – LV
What % saturation is blood from the aorta in fetal circulation? Where does it flow
58% saturated. Flows into the placenta via the umbilical arteries
Where is there mixing of saturated and unsaturated blood?
In the liver, in the IVC, in the RA, in the LA, and at the entrance of the ductus
arteriosus into the aorta
What is the initial event in transitional circulation?
Initial event that reverses the shunts is a fall in pulmonary resistance (allows blood to
start circulating through the lung)
Increased pulmonary flow _______ . Decreased flow from umbilical vein _______.
Increases pressure in the LA. Decreases pressure in the RA
What does the first breath do?
Presses the septum primum against the septum secundum. Increased LA pressure and
decreased RA pressure functionally close the foramen ovale
What is contraction of the muscular wall of the ductus arteriosus after birth mediated
If a patient has a ductus dependent lesion, what do we give them right after birth?
Prostaglandin E1 to prevent the contraction of the muscular wall of the ductus