DLA 53+54

Question 1

Fates of the 6 aortic arches

Answer 1

1. maxillary A.
2. hyloid and stapedial A.
3. common carotid A. and proximal part of the internal carotid A.
4. left: part of the arch of the aorta
   right: proximal part of the right subclavian A.
5. degenerates early or fails to develop
6. left: forms the ductus arteriosus (eventually forms ligamentum arteriosum)
   right: degenerates

Question 2

cardiovascular changes during pregnancy?

Answer 2

1. increased cardiac output
2. decreased SVR
3. increased blood volume and RBC mass
4. decreased BP

Question 3

cardiovascular changes at delivery

Answer 3

1. Cardiac output is increased

2. increased stroke volume and HR

Question 4

Three changes after birth (baby)

Answer 4

1. clamping of the umbilical cord - Closure of the foramen ovale due to the new resistance in the LA
2. Air entering lungs
3. increased oxygen concentration - closure of the ductus areteriosus

Question 5

patent ductus arteriosus

Answer 5

persistent shunt between the descending aorta and left pulmonary A.

feature: continuous murmur
treatment: surgical closure

Question 6

persistent pulmonary hypertension

Answer 6

Initial primary finding cyanosis, associated with
tachypnea and respiratory distress.

Cardiac examination: loud, single second heart sound
(S2) or a harsh systolic murmur secondary to tricuspid regurgitation.

May also present systemic hypotension, symptoms of
shock, and evidence of poor cardiac function and
perfusion