workbook chapter 2 embryologic

Prior to week 3, the heart consists of a pair of tubes situated on either side of the midline toward the caudal end of the embryo.

• true

• false

Answer explanation

Toward the cephalic

At 21-23 days, the heart tube is connected to the ______ at the cephalic end and the _______ at the caudal end.

• bulbus cordis / sinus venous

• developing aortic arch system/sinus venosus

• primitive atrium/primitive ventricle

• sinus venosus/truncus arterosus

Which of the following does the sinus venosus ultimately form?

• posterior portions of the atria

• pulmonary veins

• superior vena cava & inferior vena cava

• all of the above

What structure(s) does the interventricular sulcus divide?

• apical portion of the ventricles

• primitive atria

• primitive ventricle & bulbus cordis

• right ventricular outflow tract

Primitive atrium will divide into the ______.

• apical portion of the left ventricle

• apical portion of the right ventricle

• right and left atria

• right and left ventricles

Bulbus cordis can be divided into the proximal bulbus cordis, conus cordis, and truncus arteriosus; what do they form collectively?

• apex, atrioventricular valves, thoracic & descending aorta

• apical portion of the right ventricle, ventricular outflow tracts, aorta & pulmonary artery

• atrioventricular valves, left & right ventricle, left & right pulmonary arteries

• ventricular outflow tracts, semilunar valves, left & right pulmonary arteries

Which aortic arch forms the medial portion of the definitive aortic arch?

• left first

• left fourth

• right first

• right third

At week 4, the heart begins to beat at a heart rate of 130-150 beats per minute (bpm)--by birth the heart rate is approximately 60-70 bpm.

• true

• false

Answer explanation

The heart begins at 60-70 and reaches 130-150 by birth.

Septum primum appears from the dorsal wall of the primitive atrium, grows toward the endocardial cushions, and the ostium primum remains.

• true

• false

How do the sinus venosus and primitive atrium communicate?

• foramen ovale

• ostium primum

• ostium secundum

• sinoatrial orifice