CP Great Vessels Embryology

Question 1

When does vasculogenesis begin?

Answer 1

By the end of the third week

Question 2

What are the first to loci for the formation of blood islands?

Answer 2

Extraembryonic splanchnic mesoderm (around the yolk sac)

Aortic gonad mesonephric region (AGM)

Question 3

What arises from aortic arch 1?

Answer 3

Maxillary

Question 4

What arises from aortic arch 2?

Answer 4

Stems of the stapedial arteries

Question 5

What arises from the aortic sac?

Answer 5

Brachiocephalic artery

Base of the arch of the aorta

Question 6

What arises from aortic arch 3?

Answer 6

Internal carotid

Common carotid

External Carotid

Question 7

What arises from aortic arch 4?

Answer 7

Left: medial portion of the arch of the aorta

Right: proximal right subclavian (distal part comes from the 7th segmental artery, and another part comes from the dorsal aorta)

Question 8

What arises from arch 6?

Answer 8

Pulmonary arteries

Left: Distal ductus arteriosus

Right: Distal portion degenerates

Question 9

What arises from the 7th segmental artery?

Answer 9

Left: Entire left subclavian

Right: Distal part of the right subclavian (the proximal part came from arch 4, and another part comes from the dorsal aorta)

Question 10

What arises from the dorsal aorta?

Answer 10

Right: Portion of the right subclavian (the proximal part comes from arch 4 and the distal part from 7th segmental artery)

Left: Descending aorta

Question 11

What vessel brings oxygenated blood from the placenta to the newborn?

Answer 11

The left umbilical vein

Question 12

What structure allows placental blood to bypass the fetal liver?

Answer 12

The ductus venosus

Question 13

What do we call the neonatal remnant of the left umbilical vein?

Answer 13

The ligamentum teres (round ligament of the liver)

Question 14

What is the embryological structure that becomes the ligamentum venosum?

Answer 14

Ductus venosus

Question 15

What signaling molecule assists in the closure of the ductus arteriosus?

What signaling molecule can keep it open?

Answer 15

Bradykinin

Prostaglandins

Question 16

What causes a double aortic arch?

Answer 16

Persistence of the distal portion of the right dorsal aorta (proximal portion makes a part of the right subclavian like it’s supposed to - but then the distal portion remains.

s/s-dysphagia and dyspnea

Question 17

What causes an interrupted aortic arch?

Answer 17

Abnormal disintegration of both of the 4th aortic arch arteries

Question 18

What genetic defect is often associated with an interrupted aortic arch?

Answer 18

DiGeorge Syndrome (22q11 deletion)

Question 19

Which upper extremity (right or left) always gets blood in patients with an interrupted aortic arch?

Answer 19

The right side upper extremity.

Left side sometimes does, sometimes doesn’t. Lower extremity depends on the ventricular septal defect and patent ductus arteriosus.

Question 20

What is the function of the vitelline veins?

Answer 20

Returning blood from the yolk sac and liver to the heart.

Question 21

Proximal to the heart, which vitelline vein degenerates, and which persists?

Answer 21

Left vitelline degenerates near the heart, but the right vein persists

Question 22

What are the fates of the right and left vitelline veins in the liver?

Answer 22

Right gives rise to the hepatic vein (part of inferior vena cava)

Right and Left both give rise to the portal vein

Question 23

What part of which umbilical vein persists to bring O2 rich blood back from the placenta?

Answer 23

The distal portion of the left umbilical vein

Question 24

What blood vessels arise from the anterior cardinal veins?

Answer 24

Right: Superior vena cava

Left: Brachiocephalic Vein

Question 25

What blood vessels arise from the posterior cardinal veins?

Answer 25

Subcardinal veins Supracardinal veins Root of the azygos vein Common iliac vein

Question 26

What defect results in a left superior vena cava?

Answer 26

Obliteration of the right common cardinal vein and the proximal part of the right anterior cardinal vein. (Thus the superior vena cava has to come from the left, since the right is gone)

Question 27

What defect results in a double superior vena cava?

Answer 27

Failure of the left brachiocephalic vein to form, resulting in it forming another vena cava.

Question 28

Where do left sided superior vena cavas drain?

Answer 28

Into the coronary sinus.

Question 29

What structure gave rise to the following segment of the inferior vena cava: Hepatic

Answer 29

Hepatic veins and sinuses Right Vitelline

Question 30

What structure gave rise to the following segment of the inferior vena cava: Pre-renal

Answer 30

Right Subcardinal

Question 31

What structure gave rise to the following segment of the inferior vena cava: Renal

Answer 31

Subcardinal-supracardinal anastomosis

Question 32

What structure gave rise to the following segment of the inferior vena cava: Postrenal

Answer 32

Right Supracardinal

Question 33

S/S of a Patent Ductus Arteriosus

Answer 33

LV hypertrophy pulmonary congestion CHF treat with indomethacin or surgery **Increased risk with maternal rubella infections**

Question 34

What is coarctation of the aorta and what is it associated with?

Answer 34

* aorta is abnormally constricted. * A postductal coarctation is found distal to the origin of the left subclavian artery and inferior to the ductus arteriosus. * It is clinically associated with increased blood pressure in the upper extremities, lack of pulse in femoral artery, high risk of both cerebral hemorrhage and bacterial endocarditis. * A preductal coarctation of the aorta in which the constriction is located superior to the ductus arteriosus occurs less commonly. Assx with Turner's Syndrome

Question 35

Abberant Origin of the Right Subclavian A.

Answer 35

* occurs when right aortic arch 4 and the right dorsal aorta cranial to the seventh intersegmental artery abnormally regress. * As development continues, the right subclavian artery lies on the left side just inferior to the left subclavian artery. * The right subclavian artery must therefore cross the midline posterior to the trachea and esophagus to supply the right arm. * This anomaly may constrict the trachea or esophagus. However, it is generally not clinically significant. (possibly dysphagia )

Question 36

Where is most of the SVC blood directed into in the fetus?

Answer 36

into the RV (90% from RB enters aorta via DA, 10% enters lungs)