Embryology 2 Flashcards
Define vasculogenesis?
Defined as the new formation of a primitive vascular network
Define angiogenesis?
Defined as the growth of new vesssels from pre-existing blood vessels
Vitelline system supplies what?
Yolk sac
Cardinal system supplies what?
Body wall
Umbilical system supplies what?
Placenta
What develops during 4&5th week?
Pharyngeal arches
What is the fate of arch 1+2?
Maxillary arteries
What is the fate of arch 3?
Common carotid and first part of internal carotid arteries
What is the fate of left side of arch 4?
Arch of aorta (distal portion)
What is the fate of the right side of arch 4?
Right subclavian atery
What is the fate of the left side of arch 6?
Left pulmonary artery and ductus arteriosus
What is the fate of the right arch 6?
Right pulmonary artery
Where do most defects arise from?
Persistence of aortic arches that normally should regress or regression of arches that normally shouldnt.
What forms during double aortic arch
Vascular ring around trachea and esophagus
What is patent ductus arteriosis?
condition wherein the ductus arteriosis fails to close after birth
What symptoms can be seen in PDA?
Increased work of breathing
poor weight gain
What can PDA lead to if not untreated?
congestive heart failure
What is coarctication of the aorta?
Congenital condition where aorta is narrow, usually in the area where the ductus arteriosus inserts
What is the fate of vitelline arteries?
- Celiac artery
- Superior mesenteric artery
- Inferior mesenteric artery
What is superior mesenteric artery providing?
Midgut
What happens to umbilical arteries afterbirth?
Proximal portion= Persists as interal iliac and superior vesical branches
Distal portion=degenerates to form obliteral umbilical arteries & forms medial umbilical ligaments
What do vitelline veins drain?
yolk sac
What happens to right umbilical vein?
-Degenerates completely
What happens to left umbilical vein?
-Obliterates and forms ligamentum teres of adult liver
What happens to the ductus venosus?
Obliterates and forms ligamentum venosum
What is the fate of the cardinal veins?
Form Vena Cava (system by anastomosis) among the veins
Name some abnormalities of venous system?
Double IVC
Abscence of IVC
Left SVC
Double SVC
When does lymphatic system develop?
End of sixth week around main veins
How many primary lymph sacs develop at the end of embryonic period?
six
What are the three important vascular structures in the transitional circulation?
- Ductus venousus
- Oval foramen
- Ductus arteriosis
What does the ductus venousus do?
Shunts left umbilical vein blood flow directly to IVC; allows oxygenated blood from the placenta to bypass the liver
What does the oval foramen do?
Allows blood to enter the left atrium from the right (bypass lungs)
What does the ductus arteriosis do?
Allows blood that still escapes to the right ventricles to bypass lungs
What does the ductus venosus become?
Ligamentum venosum
What is patent ductus arteriosus associated with?
Maternal rubella infection -early pregnancy
What is the cause of patent ductus arteriosis
Failure of muscular wall to contract, respiratory distress syndrome and lack of surfactant in the lungs
