Development of Cardiovascular System Flashcards
Embryology 2
What 2 methods do blood vessels develop
Vasculogenesis
Angiogenesis
Vasculogenesis
Defined as the new formation of a primitive vascular network
Angiogenesis
Defined as the growth of new vessels from pre-existing blood vessels
What is the process of the formation of aortic sac
First arteries to appear in the embryo are the primitive aorta
Each primitive aorta has a ventral and dorsal part
Fusion of endothelial tubes form sac
What arises from aortic sac
Aortic branch
What do pharyngeal arteries communicate with and what do they form
Aortic branches
Aortic arches
How many aortic arches are formed on each side
6
What are the aortic arches in communication with
Dorsal aorta
Are all the branches present at the same time? (Y/N)
N
Arches 1 + 2 derivative
Maxillary arteries
Arch 3 derivatives
Common carotid and first part of internal carotid arteries
Arch 4 derivatives left side
Arch of aorta (distal portion)
Arch 4 derivatives right side
Right subclavian artery (proximal portion)
Arch 5 derivatives
Never forms or forms incompletely and regresses
Arch 6 derivatives left side
Left pulmonary artery and ductus arteriosus
Arch 6 derivatives right side
Right pulmonary artery
What does the ductus arteriosus become within 6 months
Closes after baby breathes Ligamentum arteriosum
What is the Ligamentum arteriosum
Fixed structure which forms as a tether between aortic isthmus and pulmonary artery
What do most defects of the great arteries arise from?
A result of persistence of aortic arches that normally should regress or regression of arches that normally shouldn’t
Aberrant subclavian artery
Regression of the right 4th aortic arch and the right dorsal aorta
What are the consequences of an aberrant subclavian artery
Forces right subclavian artery to cross the mid-line behind the trachea and oesophagus- which may constrict these organs
Double aortic arch occurs..
with the development of an abnormal right aortic arch in addition to a left aortic arch, forming a vascular ring around the trachea and oesophagus
What problems does a double aortic arch cause
Difficulty breathing and swallowing
What is patent ductus arteriosus
Ductus arteriosus fails to close after birth and can lead to congestive heart failure with increasing age
What is Coartation of the Aorta
A congenital condition where the aorta is narrow
What are the 2 types of coartation
Proximal to DA (pre-ductal)
Distal to DA (post-ductal)
What is the fate of Vitelline Arteries
In adult they are represented by arteries to the foregut, midgut and hindgut
What is the fate of Umbilical Arteries
After birth proximal portion persists as internal iliac and superior vesical branches
Vitelline veins
Return poorly oxygenated blood from the yolk sac
Umbilical vein
Originate from chorionic villi of placenta carrying oxygenated blood to the embryo
Cardinal vein
Draining of the body of the embryo
Fate of cardinal veins
Form IVC, SVC by anastomosis among the veins
What does the cardinal veins consist of
Anterior, posterior and common cardinal veins
When does the lymphatic system develop
End of sixth week and around main nerves
How many primary lymph sacs are there?
6
What are the 6 primary lymph sacs
2 Jugular
2 Iliac
Retroperitoneal
Cisterna Chyli
Good respiration in neonate is dependent upon what
Normal circulatory transition at birth (placenta circulation to pulmonary circulation)
What are the important vascular structures in the transitional circulation
Ductus venosus
Oval foramen
Ductus arteriosus
Ductus venosus
Shunts left umbilical vein blood flow directly to IVC (allows oxygented blood from, the placenta to bypass liver)
Oval Foramen
Allows blood to enter the left atrium from the right atrium (allows blood to bypass lungs)
Ductus arteriosus
Allows blood that still escaped to the right ventricle to bypass the lungs
Describe Foetal Circulation (6)
1) Blood arrives via umbilical vein
2) The ductus venosus shunts oxygenated blood from placenta away from semi-functional liver to the heart
3) Oxygented blood from placenta enters right atrium via IVC
4) The foramen ovale allows oxygenated blood in the right atrium to reach left atrium
5) the ductus arteriosus connects the aorta with the pulmonary artery shunting blood away from lungs and into aorta
6) Mixed blood travels to the head and body and back to the placenta via the aorta
Patent Ductus Arteriosus cause (5)
More common in females Rubella infection Failure of muscular wall to contract Lack of surfactant Respiratory distress syndrome