Embryology: Ventricular Septation And Development

Question 0

Primitive right and left ventricles at day 27:

Answer 0

Still local widening a of original heart tube connected by interventricular septum
Blood reaches primitive LV via the AV canal

Question 1

When does cardiac septation start, and how long does it last?

Answer 1

Starts: day 27
Lasts: 10 days

Question 2

2 simultaneous process that occur during ventricular development, resulting in chamberization:

Answer 2

1. Division of AV canal into right and left AV orifice via the endocardial cushions
2. Ventricular septation

Question 3

Functions of the endocardial cushions

Answer 3

1. Develop into AV and Conotruncal regions

2. Assist in formation of AV septa, AV canals, valves, aortic and pulmonary channels

Question 4

Where are the endocardial cushions at the end of week 4?

Answer 4

AV canal
2 lateral cushions on each side of the canal
Anterior and posterior cushions push into lumen and fuse creating complete division of the canal (finalizes end of week 5)

Question 5

Role of endocardial cushions in division of the AV canal

Answer 5

1. Form a barrier between atria and ventricles

2. Right-left division of the canal

Question 6

Where does ventricular septum begin to form and which way does it grow?

Answer 6

It is formed by the outgrowth if the muscular ridge if the inter ventricular foramen
It grows upwards from the apex of the heart
Outgrowth of tissue from the endocardial cushion on the top of the inter ventricular septum closes the foramen (fuses with conus septum)

Question 7

Anatomically, what is the interventricular septum?

Answer 7

The space above the membranous septum.