Chapter 12: Cardiovascular System

Chapter 12: Cardiovascular System

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

Directions: Each group of questions below consists of a numbered list of descriptive words or phrases accompanied by a diagram with certain parts indicated by letters or by a list of lettered headings. For each numbered word or phrase, select the lettered part or heading that matches it correctly, and then insert the letter in the space to the right of the appropriate number. Sometimes more than one numbered word or phrase may be correctly matched to the same lettered part or heading.

________ Directs blood into the left atrium

ANS:   C

Blood from the inferior vena cava (IVC) is directed by the inferior border of the septum secundum (crista dividens) through the oval foramen into the left atrium.

________ Carry relatively little fetal blood

ANS:   D

The pulmonary veins carry relatively little blood to the left atrium before birth because the lungs are not functioning. When the lungs expand at birth and the pulmonary vascular resistance falls, there is a marked increase in pulmonary blood flow with a consequent increased flow of oxygenated blood to the left atrium through the pulmonary veins.

________ Remains of the septum primum

ANS:   E

The remains of the septum primum are represented in the drawing by the valve of the oval foramen. This valve is forced open by blood from the IVC that is directed through the oval foramen by the crista dividens (inferior edge of septum secundum). The oval foramen normally closes at birth when pressure in the left atrium rises above that in the right atrium.

________ Opening in the septum secundum

ANS:   B

The oval foramen is a normal opening in the septum secundum. It permits well-oxygenated blood from the placenta that comes from the IVC to enter the left atrium. If the oval foramen fails to close at birth, a cardiac anomaly known as secundum-type ASD exists. This common congenital heart defect accounts for about 8% of cases of congenital heart disease.