5. Adaptation at birth

Question 1

Changes of vascular system at birth

Answer 1

Cessation of placental flow

Beginning of respiration

Question 2

Closure of umbilical artery by contraction

Answer 2

thermal
mechanical
change in O2 tension

Question 3

When does fibrous proliferation of umbilical artery occur ?

Answer 3

2-3 months

Question 4

Ductus arteriosus

Answer 4

Contactraction of muscular wall
Bradykinin + cytochrome p450 released by lung
Complete obstruction 1-3 months
Forms Ligamentum arteriosum

Question 5

Foramen Ovale

Answer 5

Ceases to carry blood and slowly closes
Reduces blood to RA through IVC
Decreases pressure in RA
Reduces right to left atrial flow
Forms Fossa ovalis

Question 6

Order of Haematopoiesis

Answer 6

Yolk Sac
AGM Region
Liver
Spleen
Bone Marrow

Question 7

Fetal haemoglobin - HbF

Answer 7

HbF has a higher oxygen affinity than HbA

Enables HbF to take up oxygen from maternal blood which is at the same partial pressure

At tissue:
High haematocrit
Acidic pH – greater ability to unload O2

Question 8

Ductus venous forms…

Answer 8

Ligamentum venosum

Question 9

Umbilical vein(left) forms…

Answer 9

Ligamentum teres

Question 10

Ductus arteriosus forms…

Answer 10

Ligamentum arteriosum

Question 11

Foramen Ovale forms…

Answer 11

Fossa Ovalis

Question 12

Distal segments of Umbilical arteries form…

Answer 12

medial umbilical ligament

Question 13

Proximal segments of Umbilical arteries form…

Answer 13

superior vesical arteries