Chapter 12 Cardiovascular System

Chapter 12  Cardiovascular System

Complete Chapter Questions And Answers
 

Sample Questions

7. ________ Round ligament of the liver
a.
Ductus arteriosus
b.
Septum primum
c.
Sixth pharyngeal arch artery
d.
Sinus venosus
e.
Umbilical vein

ANS: E
The intra-abdominal part of the fetal umbilical vein becomes the adult round ligament of the liver (L. ligamentum teres hepatis). It passes from the umbilicus to the porta hepatis, where it attaches to the left branch of the portal vein.

8. ________ Carries poorly oxygenated blood into the right atrium
a.
Ductus arteriosus
b.
Septum primum
c.
Sixth pharyngeal arch artery
d.
Sinus venosus
e.
Umbilical vein

ANS: D
The sinus venosus initially is a separate chamber of the heart that opens into the caudal wall of the right atrium. The right horn of the sinus venosus becomes incorporated into the wall of the right atrium and forms its smooth-walled part called the sinus venarum. The left horn of the sinus venosus becomes the coronary sinus.

9. ________ Arterial shunt
a.
Ductus arteriosus
b.
Septum primum
c.
Sixth pharyngeal arch artery
d.
Sinus venosus
e.
Umbilical vein

ANS: A
The ductus arteriosus is an arterial shunt that carries blood from the left pulmonary artery to the arch of the aorta before birth. Because the lungs are not functioning, most of the blood in the pulmonary trunk bypasses the lungs and enters the descending aorta.

10. ________ Floor of the oval fossa
a.
Ductus arteriosus
b.
Septum primum
c.
Sixth pharyngeal arch artery
d.
Sinus venosus
e.
Umbilical vein

ANS: B
The floor of the oval fossa in the interatrial septum is formed by tissue derived from the septum primum (valve of oval foramen). When the pressure in the left atrium rises at birth, the valve of the oval foramen closes and later fuses with the septum secundum. This valvular tissue forms the floor of the oval fossa.