Session 2

Question 1

What are the stages of heart development?

Answer 1

1. Cell Migration
2. Heart Tube Formation
3. Looping of the Heart Tube
4. Septation into 4 Chambers

These stages outline the sequential process of heart formation.

Question 2

What days mark the formation of the primitive streak?

Answer 2

Days 13 - 14

This is when the node forms at the caudal end.

Question 3

What primary germ layers develop between days 15 - 17?

Answer 3

• Ectoderm
• Mesoderm
• Endoderm

These layers are essential for the formation of various tissues and organs.

Question 4

What happens to the mesoderm between days 17 - 18?

Answer 4

Mesoderm splits into somatopleuric and splanchnopleuric mesoderm

This division is critical for further development of the heart and other structures.

Question 5

When do the endocardial cells form into two lateral endocardial tubes?

Answer 5

Days 18 - 22

This is a key step in heart tube formation.

Question 6

What occurs during the fusion of endocardial tubes?

Answer 6

Formation of cardiac jelly

Cardiac jelly separates myocardium from endocardium

Question 7

What are the three distinct regions formed during heart tube fusion?

Answer 7

• Cranial
• Bulbis cordis
• Caudal

These regions play specific roles in heart development.

Question 8

What day marks the beginning of the heartbeating?

Answer 8

Day 22

This indicates the functional start of the heart.

Question 9

What are the components of the heart tube?

Answer 9

• Truncus arteriosus
• Bulbus cordis
• Interventricular sulcus
• Primitive ventricle
• Atrioventricular sulcus
• Primitive atrium
• Crista terminalis
• Sinus venosus

Each component has a specific role in the structure and function of the heart.

Question 10

What occurs during heart looping between days 22 - 28?

Answer 10

Bending rightward to create primitive ventricle

This process is essential for proper heart chamber formation.

Question 11

What function does cardiac jelly serve during heart looping?

Answer 11

Functions as a valve for blood flow

This ensures proper circulation within the developing heart.

Question 12

What does the truncus arteriosus transform into?

Answer 12

• Pulmonary trunk
• Aortic arch

Question 13

What does the sinus venosus become?

Answer 13

Smooth portion of the right atrium

SA node
Fossa ovali
Coronary sinus
Superior vena cava
Inferior vena cava

Question 14

What are the primary germ layers composed of?

Answer 14

• Ectoderm
• Mesoderm
• Endoderm

These layers are foundational to the development of various organ systems.

Question 15

When do the endocardial tubes form?

Answer 15

Days 18 - 22

This is a critical period in the development of the heart.