CVS- Development

Question 0

What is the cardiogenic region?

Answer 0

Cardiac myoblasts and blood islands

Question 1

Which germ layer do progenitor heart cells become?

Answer 1

Mesoderm

Question 2

What is the benefit of cephalocaudal folding?

Answer 2

This positions the heart in the chest

Question 3

What is the benefit of lateral folding to CVS development?

Answer 3

This joins the caudal regions of the paired cardiac tube.

Question 4

What are the names of the sections of the primitive heart tube? From bottom upwards (caudal - cranial)

Answer 4

The SINUS VENOSUS recieves blood from the embryo 
This passes into the ATRIUM.
Then passes up to the VENTRICLE 
Up to the BULBUS CORDIS
then to the TRUNCUS ANTERIOSUS 
and out through the aortic roots

Question 5

How does looping occur?

Answer 5

As the outflow tract lengthens the cardiac tube begins to bend
The cephalic portion bends ventrally and caudally and to the right
The caudal portion shifts dorsocranially and to the left

Question 6

What leads to the formation of the transverse pericardial sinus?
And what is it?

Answer 6

Looping
It is the position of arteries in front of veins
Between the aorta and pulmonary artery infront and superior vena cava behind.

Question 7

After looping how does the atrium communicate with the ventricles?

Answer 7

Via the atrioventricular canal

Question 8

What incorporates into the primitive atrium to form the RA?

Answer 8

The right sinus horn

Question 9

What is the LA developed from?

Answer 9

A small portion of primitive atrium, proximal parts of pulmonary veins.

Question 10

Why is fetal circulation carried out through the placenta?

Answer 10

Because the lungs are the last body system to develop

Question 11

What are circulatory shunts?

Answer 11

Small passages that direct blood to be oxygenated

Question 12

What is the name of the shunt that bypasses the lungs from the pulmonary trunk to the aorta?

Answer 12

The ductus arteriosus

Question 13

How does blood get from the IVC to the Right atrium?

Answer 13

Placenta to IVC by ductus venosus

IVC to RA

Question 14

How does the arterial system begin?

Answer 14

As a bilaterally symmetrical system of arched vessels.

Question 15

After looping of the heart what links the two chambers?

Answer 15

The atrioventricular canal

Question 16

What grows to divide the AV canal into left and right channels

Answer 16

Endocardial cushions

Question 17

How many septa and holes are involved in atrial septation?

Answer 17

2 septa and 3 holes

Question 18

Describe atrial septation

Answer 18

The septum primum grows down towards the endocardial cushions
The ostium primum is the hole present before septum primum fuses
The ostium secundum appears before the OP closes
A second crescent shaped septum grows - septum secundum
The hole in this is called the foramen ovale

Question 19

What is the foramen ovale used for?

Answer 19

Used as shunt in foetal circulation to allow blood flow from right to left

Question 20

What is the adult remnant of the foramen ovale?

Answer 20

The fossa ovalis

Question 21

What are the two components of the ventricular septation?

Answer 21

Muscular and membranous

Question 22

How does the muscular portion of the ventricular septum grow?

Answer 22

Up towords the endocardial cushions

Leaves a Hole at the top called a primary interventricular foramen

Question 23

How does the membranous portion of the ventricular septum form?

Answer 23

Derived from spiral septum this covers the primary interventricular foramen.

Question 24

What is the fate of the ductus arteriosus?

Answer 24

Ligamentum arteriosus

Question 25

What is the fate of the ductus venosus?

Answer 25

Ligamentum venosus