Term
| Formation of dorsal aorta |
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Definition
Bilateral angiogenic cell clusters form near the midline of the early embryo.
These clusters coalesce to form the 2 lateral tubes of the dorsal aorta in the cranial portion of the embryo.
Lateral folding of the embryo causes the two tubes of the dorsal aorta to fuse caudal to the aortic arches. The dorsal aorta splits on both sides between arches 3 and 4. Portion remaining of arch 3 becomes part of internal carotid. Portion remaining on arch 4 becomes part of subclavian on right, part of aortic arch on left. |
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Term
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Definition
Carry oxygenated blood to pharyngeal pouches and dorsal aorta. Have one aortic arch to each pharyngeal pouch, associated with cartilage (eventually forms into bone) and nerves.
Form from the aortic sac.
Ventral attachment is aortic sac, dorsal attachment is dorsal aorta. |
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Term
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Definition
Most distal part of the truncus arteriosis, give off aortic arches to each pharyngeal pouch. Branches to form left and right horns as the truncus arteriosis divides into aortic and pulmonary trunks.
Right horn=brachiocephalic artery
Left= aortic arch |
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Term
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Definition
I, II, III, IV, V (transient or never forms), VI
Forms cranial to caudal (I first, II second, etc.)
Out of these branches, III, IV, and VI remain in mature vasculature. |
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Term
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Definition
| Small portion becomes maxillary artery. Arch is transient. |
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Term
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Definition
| Small portion becomes strapedial and hyoid arteries. Associated cartilage also goes on to form hyoid bone. |
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Term
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Definition
| Becomes common carotid artery. Common carotid artery intersects with dorsal aorta to form internal carotid. External carotid branches out from internal carotid. |
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Term
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Definition
| Associated with 6th aortic arch, supplies the same structures (larynx, called recurrent laryngeal nerves). Higher on right side than left, since ligamentum arteriosum is on left, which drags nerve down. On the right side, the 6th arch detaches from the dorsal aorta, which creates room for the vagus nerve to ascend to the level of the 4th arch. |
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Term
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Definition
Left side: becomes part of aortic arch.
Right: portion of subclavian artery |
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Term
| Splitting of dorsal aorta on right side |
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Definition
| Splits between arches 3,4 to become internal carotid and subclavian respectively. Also disconnects from the fused midline dorsal aorta and 6th arch. Seventh intersegmental artery branches from this splitting, eventually forms portion of the subclavian artery. |
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Term
| Components of the subclavian artery |
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Definition
1. 4th arch
2. Dorsal aorta
3. 7th intersegmental artery |
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Term
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Definition
| Right dorsal aorta doesn't split between 6th arch and midline, creates double aorta that can constrict esophagus. |
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Term
| Left subclavian artery origin |
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Definition
| Comes from left 7th intersegmental artery |
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Term
| Abnormal origin of right subclavian artery |
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Definition
Crosses posterior to esophagus.
Caused by
1. Abnormal obliteration of 4th arch
2. Abnormal retention of right dorsal aorta at midline
Right subclavian is attached to left aorta->right dorsal aorta->7th intersegmental |
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Term
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Definition
1. Truncus (or left horn aortic sac)
2. 4th arch
3. Dorsal aorta |
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Term
| Left side splitting of dorsal aorta |
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Definition
| Splits between arch 3 and 4, retains all other connections. |
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Term
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Definition
| When 4th aortic arch doesn't connect with dorsal aorta, terminates descending aorta. In fetal life, the ductus arteriosis (connection between the 6th aortic arch and the dorsal aorta) keeps systemic circulation going. However, problems occur after childbirth once the ductus arteriosis closes into the ligamentum arteriosum. Coarctation creates a gradient of BP across the body that can be detected by measuring the BP in different extremities. |
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Term
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Definition
| No aortic arch. Both left and right 4th aortic arches are obliterated while the right dorsal aorta stays attached to the midline (causes abnormal origin of right subclavian artery). Causes a patent ductus arteriosis to channel blood to descending aorta (origin=left dorsal aorta) through the pulmonary artery. |
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Term
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Definition
As truncus arteriosis septates, the 6th aortic arch becomes part of the pulmonary trunk.
Right side: pulmonary artery
Left side: ductus arteriosis. |
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Term
| Lateral branches of abdominal aorta |
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Definition
1. Suprarenal (comes off descending aorta)
2. Gonadal (Sprout off aorta from T10, descend to L3-L4)
3. Renal |
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Term
| Major arterial system branches |
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Definition
1. Lateral branches
2. Body wall branches
3. Anterior branches |
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Term
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Definition
1. Intersegmental artery system (arteries to somites)
2. Intercostal arteries (arteries to thorax)
3. Lumbar arteries (arteries to lumbar and sacral regions). |
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Term
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Definition
Travel from yolk sac to embryo endoderm. Form arteries in dorsal mesentery of the gut.
1. Celiac artery (foregut)
2. Superior mesenteric artery (midgut)
3. Inferior mesenteric artery (hindgut) |
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Term
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Definition
| Come off of dorsal aorta as pair. Bring blood from placenta to embryo, have 2 arteries to 1 vein. |
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Term
| O2 saturation in placental blood |
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Definition
| 80%. Due to deoxygenated portal blood mixing. |
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Term
| Pathway of fetal circulation from umbilical vein |
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Definition
| Placenta->umbilical vein->ductus venosis->IVC->right atrium->left atrium (via foramen ovale)->left ventricle->aorta |
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Term
| Locations of oxygenated and deoxygenated blood mixing in fetal circulation |
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Definition
1. IVC mixes oxygenated placental blood with deoxygenated blood from lower limbs.
2. In right atrium, deoxygenated blood in upper extremities travel down SVC to mix with oxygenated blood. |
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Term
| Pathway of fetal circulation from lower extremity |
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Definition
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Term
| Pathway of fetal circulation from upper extremity |
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Definition
| SVC->RA->RV->Ductus Arteriosis->Aorta |
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Term
| Pathway of fetal circulation from aorta |
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Definition
| 58% saturated. Feeds body, then travels down umbilical arteries to placenta. |
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Term
| Closure of the foramen ovale |
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Definition
| Created by switch in pressure in right and left atria (increased pulmonary flow in left atria, decreased umbilical flow from right atrium, causes septum primum to close over septum secundum. |
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Term
| Closure of ductus arteriosis |
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Definition
Muscular wall of the artery contracts after birth.
Mediated by Bradykinin, can be inhibited by prostaglandin e.
Obliteration can take weeks. |
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Term
| Contraction of umbilical arteries |
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Definition
| Contraction of smooth muscles of arteries shuts down arteries. |
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Term
| Closure of umbilical veins and ductus venosis |
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Definition
| Closure occurs just before umbilical artery closure. Veins become ligamentum teres. Ductus venosis becomes ligamentum venosis. |
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