Heart II

Question 1

Horseshoe shaped region of mesoderm extending from the anterior part of the embryo back on both sides of the foregut

Answer 1

Cardiogenic mesoderm

Question 2

The heart develops from which embryonic tissue layer?

Answer 2

Mesoderm

Question 3

The space, the pericardial coelom, will eventually be divided by folds to form the:

Answer 3

– Pericardial space
– Pleural space(s)
– Peritoneal space(s)

Question 4

Dextrocardia

Answer 4

Bending of the heart tube to the left instead of the right . L-loop positions apex to right (Normal: Apex to the left)

Question 5

Situs inversus

Answer 5

Inverted position of abdominal and thoracic organs

Question 6

The Fates of Heart Tube:
Truncus Arteriosus
Bulbus Cordis
Primordial Ventricle
Primordial Atrium
Right horn of Sinus Venosus
Left horn of sinus venosus

Answer 6

Truncus Arteriosus- Pulmonary Trunk & Ascending Aorta

Bulbus Cordis- Conus Arteriosus & Aortic Vestibule

Primordial Ventricle- Rt & Lt Ventricle (trabeculated part)
Primordial Atrium- Rt & Lt Atrium (Rough-Walled Part)

Right horn of Sinus Venosus- Rt. Atrium

Left horn of sinus Venosus- Coronary Sinus

Question 7

….. grow towards each other and separate the Rt anf Lt atria from the Rt and Lt ventricle

Answer 7

Endocardial Cushions

Question 8

The opening between septum secundum and septum primum is called ……

Answer 8

Foramen ovale or oval foramen

Question 9

The right and left horn of the sinus venosus becomes….

Answer 9

Right horn- Right Atrium

Left horn- Left Atrium

Question 10

Atrial Septal Defect: Probe Patent Foramen Ovale

Answer 10

Due to incomplete adhesion between septum primum and septum secundum
- No Clinical Manifestations

Question 11

ASD – Secundum Type

Answer 11

Foramen secundum is abnormally large due to a short septum secundum or excessive resorption of septum primum

Question 12

ASD – Primum Type

Answer 12

Failure of closure of foramen primum.
• The AV valves may be abnormal.
• Often present in Down Syndrome (endocardial cushion defect)

Question 13

ASD- Sinus venosus type

Answer 13

Incomplete resorption of sinus venosus into right atrium OR abnormal development of upper part of septum secundum

Question 14

The truncus arteriosus is divided into the ……

Answer 14

Aorta and Pulmonary Artery

Question 15

How is the truncus arteriosus is divided into the Aorta and Pulmonary Artery?

Answer 15

Aorticopulmonary septum grows in a spiral pattern ( spiral septum) resulting in the aorta leaving the heart posterior to pulmonary artery

Question 16

Caused by failure of tissue from endocardial cushions to fuse with the primordial IV septum and the bulbar septum

Answer 16

Ventricular Septal Disease

Question 17

Endocardial cushions are involved in formation of :

Answer 17

• Interatrial septum,
• Interventricular septum
• AV valves

Question 18

Migrating neural crest cells from the region of hindbrain form the

Answer 18

Spiral septum( truncal) and bulbar septum