Anatomy - Week 5 - Development, Circulation And Conduction Of The Heart

Question 1

When does the heart begin to function?

Answer 1

Around the 3rd week (necessary in order to meet nutrient needs of the rapidly growing embryo

Question 2

What do clusters of angiogenenic cells form?

Answer 2

A “horseshoe-shaped” cluster anterior and lateral to the brain plate

Question 3

How are blood vessels formed?

Answer 3

A series of blood island eventually coalesce.

Question 4

What are the 3 systems of paired veins that drain into the heart during embryonic circulation?

Answer 4

Vitelline veins (returning blood from yolk sac)
Umbilical veins (bring blood from the placenta)
Cardinal veins (returning blood from various parts of the body)

Question 5

What are the dilatations form from the primative heart tubes ?

Answer 5

Truncus  ateriosis 
Bulbus cordis (including conus cordis)
Primitive ventricle 
Primitive atrium
Sinus venosus (forms vena cava later on)

Question 6

What happens when the endocardial tubes combine)

Answer 6

Apoptosis (cell death) occurs in the midline to give a single tube