THE CARDIOVASCULAR SYSTEM

EMBRYOLOGY:

In which region do these cords develop?

The picture shows the tranverse section of the embryo demonstrating the formation of the angioblastic cords

What is the significance of this folding?

The picture shows the lateral folding of the embryo and the fusion of the endocardial heart tubes

What are the five dilatations which form on the primordial heart tube? What results in the bending of the heart tube?

This picture shows the formation of cardiac loop

Give the three pairs of veins which are received by the sinus nenosus.

The picture shows the structure of a primordial heart

Describe the circulation of blood through the primordial heart.

The picture shows blood circulation through a primordial heart

What are endocardial cushions and what is their significance?

The picture shows the formation of endocardial cushions

Give the two septa which are responsible for the formation of the interatrial septa.

The picture shows the septation of the atrium in the primordial heart

What results in the perforations denoted by the red arrows?

What results in the formation of foramen primum and foramen secundum? What is its significance?

What result in the formation of foramen ovale? What is the significance of this foramen?

What structure does formen ovale forms in the adult?

Which structure is responsible for this division?

The diagram shows the division of the sinus venosus into the left and right horns

What are the derivatives/remnants of the left horn of the sinus venosus?

What is the fate of the right horn of the sinus venosus?

What is the significance of this absorption?

The picture shows the absorption of the pulmonary vein into the left atrium

What forms the pars muscularis of the interventricular septum?

The diagram shows the septation of the ventricle

What forms the pars membrenacea of the interventricular septum?

The diagram shows the septation of the ventricle

What are bulbar and truncal ridges?

The picture shows the development of the truncus arteriosus and the bulbus cordis

What results in the formation of this septum?

The picture shows the formation of the aorticopulmonary septum

What is the significance of this septum?

This diagram illustrates the spiral form of the aorticopulmonary septum

How does the aortocopulmonary septum contribute towards this twisting?

The diagram shows the great arteries twisting around each other as they leave the heart

Short essay questions Describe the formation of the interatrial septum. (10 marks) Describe the formation of the interventricular septum. (8 marks) Describe the septation of the atrio-ventricular canal. (3 marks)

Multiple choice questions The umbilical arteries form the following structures in the

adult

a) Medial umbilical ligament. b) Ligamentum arteriosum. c) Ligamentum venosum. d) Superior vesical arteries. e) Ligamentum teres.

The interatrial septum is formed by

a) Pars muscularis. b) Septum primum and septum secundum. c) Septum secundum and foramen secundum. d) Septum primum and foramen primum. e) Pars membranacea.