defects (bicuspid aortic valve, or ventricular septal defect) and is common
in Turner’s syndrome.
A patent ductus arteriosus (answer a)wouldnotcause the difference
in arm and leg blood pressures. Most people with Tetralogy of Fallot
(answer b)require surgery prior to age 6. Transposition of the great arter-
ies(answer c)requires immediate surgery after birth in most instances. An
enlarged right heart border (answer e)wouldnotoccur in this girl.
355.The answer is d.(Moore and Dalley, pp 63, 166–167.)Afferent inner-
vation from the heart and coronary arteries travel within the cardiac plexus
of nerves along the sympathetic pathways. Once the afferent fibers pass
through the cardiac plexus, they run along the cervical and thoracic cardiac
nerves to the cervical and upper four thoracic sympathetic ganglia. Having
traversed these ganglia, the fibers gain access (via the white rami communi-
cantes) to the upper four thoracic spinal nerves and the corresponding lev-
els of the spinal cord. The visceral afferent fibers associated with the vagus
nerve (answer e)are associated with reflexes and do not carrynociceptive
information. The greater (answer b),lesser, and least splanchnic nerves
convey visceral afferents from the abdominal region. Neitherthe carotid
branch of the glossopharyngeal nerve (answer a)northe phrenic nerve
(answer c)carry cardiac pain fibers.
356.The answer is b. (Moore and Dalley, p 151. Sadler, p 178.)The addi-
tional heart defect the newborn girl also has is a ventricular septal defect.
Babies born with transposition of the great vessels normally present with
symptoms of cyanosis as the ductus arteriosus closes within the first day of
birth. In this defect, the aorta is sitting on top of the right ventricle and the
pulmonary trunk is receiving blood from the left ventricle, therefore blood
is being pumped mainly to the body by the right side and mainly to the
lungs by the left side. The only way oxygenated blood is traveling to the
body is if the two sides are connected, often by a patent ductus arteriosus.
Babies with this defect are immediately put on oxygen, and prostaglandins
are also given to help keep the ductus arteriosus open longer than normal.
About 25% of the time that transposition of the great vessels is present,
there is also a ventricular septal defect, which aids in the intermixing of blood
from the two sides of the heart. This condition must be treated surgically.
Defects of the aortic arch are normally notpresent. The presence of a ligamen-
tum arteriosum (answer c)would make the problem worse. Coarctation of
486 Anatomy, Histology, and Cell Biology