381.A slender 53-year-old woman who smokes a pack of cigarettes each
day comes to your office complaining of a pulsating sensation in her
abdomen with generalized abdominal and back pain. You palpate her
abdomen and feel a mid-line pulse with every heart beat. You order an
abdominal Doppler ultrasound, which shows a large, high abdominal aor-
tic aneurysm above renal arteries of about 8 cm in diameter. She is admit-
ted to the hospital immediately for repair of her aortic aneurysm because it
is life threatening, but you warn her that one of the complications of such
surgical repair includes paraplegia. During the procedure the vascular sur-
geon must completely clamp off the abdominal aorta for about an hour
while repairing the aneurysm. Which of the following would explain to the
patient why there is a risk of paraplegia?
a. Stopping the blood within the abdominal aorta causes the muscle of the lower
limbs to die
b. Stopping the blood within the abdominal aorta causes the peripheral nerves of
the lower limb to die
c. Stopping the blood within the abdominal aorta causes loss of blood flow to the
major radicular artery (of Adamkiewicz), which causes the motor components
in the spinal cord for the lower limb to die
d. Stopping the blood within the abdominal aorta causes microemboli within the
lower limb to form during the surgery and those microemboli then pass
through the lung and left side of the heart into the brain where they selectively
lodge in the motor cortex that controls the lower limbs
e. Stopping the blood within the abdominal aorta causes excessive perfusion of
the brain during the surgery, which selectively causes bleeding stroke within
the motor cortex that controls the lower limbs
382.The lateral umbilical fold serves as the demarcation for whether an
inguinal hernia is direct or indirect. The lateral umbilical fold on each side
of the inner surface of the anterior abdominal wall is created by which of
the following underlying structures?
a. Falx inguinalis
b. Inferior epigastric artery
c. Lateral border of the rectus sheath
d. Obliterated umbilical artery
e. Urachus
498 Anatomy, Histology, and Cell Biology