Lecture 6 – Development of the heart and blood vessels

Question 1

Human embryo develops into … (2)

Answer 1

Trophoblast - provides nutrients for embryo. forms outer layer of …
Blastocyst - implanted in womb, forms embryo

Question 2

Zygote/Embryo cell development (4)

Answer 2

Morula - day 4 - ball of cells formed as zygote undergoes cleavage.
early blastocyst - day 6 - hollow ball of cells with a fluid filled cavity
late blastocyte - day 10 - pre-embryo with the embryo disc two layers of cells.
gastrula - day 16 - embryo with three primary germ layers - ectoderm, mesoderm, endoderm.

Question 3

Gastrula 3 primary germ layers (3)

Answer 3

Ectoderm - Skin/CNS
Mesoderm - Heart, skeletal muscle/ Kidneys
Endoderm - Lining of GI/Lungs/Pancreas

Question 4

Foetal circulation and birth (2)

Answer 4

Foetuses overcome pulmonary circulation by:

1) Ductus arteriosus - Blood from RV. Pulmonary artery into aorta. Closes to form ligamentum arteriosus.
2) Foramen Ovalis - RA –> LA. Closes to form fossa ovalis.