Great Vessels Embryology

Question 1

Vasculogenesis

Answer 1

Formation of new vascular channels by assembly of angioblasts. From mesoderm.
Isolated accumulations unite to form plexuses, channels form within plexuses, and enlarge to form arteries and veins.

Question 2

Angiogenesis

Answer 2

Development of blood vessels from pre-existing vessels. Occurs in adults and during cancers.

Question 3

Arteriogenesis

Answer 3

Remodeling of existing arteries in response to changes.

Question 4

Capillary hemangioma

Answer 4

Excessive growth of small capillary networks.

Cherry angiomas.

Question 5

Cavernous hemangioma

Answer 5

Proliferation of large dilated vascular channels.

Question 6

Hemangioma of infancy

Answer 6

Vasculogenesis malfunction.
Benign tumor, can regress.
Up to 10% in whites.
Consists of many endothelial cells.

Question 7

Vascularization begins by:

Answer 7

Formation of EE splanchnic mesoderm surrounding the yolk sac/UV and in the AGM. form a plexus which form vessels.

Question 8

Ventral segmental arteries

Answer 8

Supply splanchnic layer and endoderm.

Question 9

Lateral segmental arteries

Answer 9

Supply intermediate mesoderm.

Question 10

Dorsal segmental arteries

Answer 10

Supply derivative of the somites.

Question 11

1st aortic arch becomes (2):

Answer 11

External carotid a. and maxillary a.

Question 12

2nd aortic arch becomes (1):

Answer 12

Stems of the stapedial as.

Question 13

3rd aortic arch becomes (2):

Answer 13

Common carotid a. and internal carotid a.

Question 14

Left 4th aortic arch becomes (1):

Answer 14

Medial part of aortic arch.

Question 15

Right 4th aortic arch becomes (1):

Answer 15

Right proximal subclavian a.

Question 16

Left 6th aortic arch becomes (1):

Answer 16

Left distal ductus arteriosus

Pulm. as.

Question 17

Right 6th aortic arch becomes (1):

Answer 17

Distal part degenerates.

Pulm. as.

Question 18

Aortic sac becomes (2):

Answer 18

Brachiocephalic trunk

Base of aortic arch.

Question 19

Right 7th intersegmental a. becomes:

Answer 19

Distal part of right subclavian a.

Question 20

Left 7th intersegmental a. becomes:

Answer 20

Entire left subclavian a.

Question 21

Right dorsal aorta becomes:

Answer 21

Part of right subclavian a.

Question 22

Left dorsal aorta becomes:

Answer 22

Descending aorta.

Question 23

Describe how the right recurrent laryngeal n. goes underneath the brachiocephalic trunk/right subclavian a.

Answer 23

The 6th aortic arch degenerates allowed it to tuck under the bct/rsa.

Question 24

Fetal circulation

Answer 24

Umbilical v. -> liver (ductus venosus) -> IVC -> RA -> LA (via foramen ovale and foramen secundum) -> LV -> aorta

Question 25

Aeration of the lungs at birth

Answer 25

Pulm resistence decreases, increases blood flow, thinning of the pulmonary as.

Question 26

How does the foramen ovale and foramen secundum close?

Answer 26

After birth the increased pressure in the LA causes the septa to adhere.

Question 27

Effect of oxygen levels on ductus arteriusus

Answer 27

Increased oxygen decreases PGs and increased bradykinin which closes the DA.

Question 28

Persistent ductus venosus

Answer 28

Acyanotic
High pressure from aorta goes into pulm. trunk.
Can destroy capillary beds in lungs (pulm htn).

Question 29

Preductal coarctation of the aorta

Answer 29

Causes a problem when DA closes (blood can get by because the DA is open).
Can be cyanotic. Treated with PGs to keep DA open.
Increase in pulse in UE and decreased pulse in LE.

Question 30

Postductal coarctation of the aorta

Answer 30

Fetus will develop alternate/collateral circulation.

Question 31

Causes of coarctation (2 hypotheses)

Answer 31

Smooth muscle constriction

Abn remodeling of aortic arches.

Question 32

Double aortic arch

Answer 32

Persistence of the distal part of the right dorsal aorta.
Forms ring around the trachea and esophagus.
Presents with respi and GI sx.

Question 33

Interrupted aortic arch

Answer 33

Right and left aortic arch as. are obliterated.
Distal right dorsal aorta is retained.
Presents w/ weakness, fatigue, tachycardia, tachypnea, low o2 sats.
Associated with DiGeorge syndrome.

Question 34

Abn. origin of right subclavian a.

Answer 34

Right 4th aortic arch and proximal part of aorta obliterate.

Rt. subclavian a. passes behind esophagus and trachea.

Question 35

Right aortic arch

Answer 35

Left 4th arch and left dorsal aorta are obliterated and replaced by corresponding vessels on the right side.

Question 36

When does remodeling of the inflow to the heart occur?

Answer 36

Wks 4-8

Question 37

Vitelline v. (R/L)

Answer 37

O2 poor blood from yolk sac and liver.
Near the heart
Rt vein persists.
Lf. vein 
In the liver
Rt forms hepatic v.
R/L forms portal v.

Question 38

Umbilical v. (R/L)

Answer 38

O2 rich from placenta.
Rt degenerates
Left persists: proximal part degenerates, but distal part anastomoses with DV providing venous return.

Question 39

Anterior Cardinal v. (R/L)

Answer 39

Drainage from cranial region.
Rt. forms the internal jugular v. and SVC.
Lt. forms Left brachiocephalic v.

Question 40

Posterior Cardinal v.

Answer 40

Drainage from the body wall.
Degenerates except for root of azygos and common iliac vs.
Replaced by subcardinal and supracardinal vs.

Question 41

Left SVC

Answer 41

Persistence of left anterior cardinal v. and obliteration of common cardinal v. and proximal anterior cardinal v. on the right.

Question 42

Double SVC

Answer 42

Persistence of the left anterior cardinal vein and failure of left brachiocephalic v. to form.

Question 43

IVC contributions (4)

Answer 43

Hepatic segments - rt. vitelline/hepatic vs.
Prerenal - rt. subcardinal v.
Renal - subcardinal-supracardinal anastomosis
Postrenal - Rt. supracardinal v.