Embriology

Question 1

When does the heart start beating spountaneously in an embryo?

Answer 1

4 weeks of development

Question 2

Dextrocardia is seen in ______ syndrome

Answer 2

Kartagener syndrome: primary ciliary dyskinesia

Question 3

Cardiac looping begins in week ___ of gestation

Answer 3

4

Question 4

Ascending aorta and pulmonary trunk develop from which embryonic structure?

Answer 4

Truncus arteriosus

Question 5

Smooth parts (outflow tract) of left and right ventricles develop from

Answer 5

Bulbus cordis

Question 6

Embryonic origin of:

• Atrial septum
• Membranois IV seputm
• AV and semilunar valves

Answer 6

Endocardial cushion

Question 7

Embryonic origin of: Smooth part of left atrium

Answer 7

Primitive pulmonary vein

Question 8

Embryonic origin of: coronary sinus

Answer 8

Left horn of sinus venosus

Question 9

Embryonic origin of: Smooth part of right atrium

Answer 9

Right horn of sinus venosus

Question 10

Embryonic origin of: SVC

Answer 10

Right common cardinal vein and right anterior cardinal vein

Question 11

Patent foramen ovale can lead to _____________

Answer 11

Paradoxical emboli: venous thromboemboli that enter systemic arterial circulation

Question 12

Failure of septum primum and septum secundum fusion after birth

Answer 12

Patent foramen ovale

Question 13

Most common congenital cardiac anomaly

Answer 13

Ventricular septal defect: membranous septum mostly

Question 14

Ventricular septal defect usually occours in

Answer 14

Membranous septum

Question 15

Conotruncal abnormalities associated with failure of neural crest cells to migrate

Answer 15

1. Transposition of great vessels
2. Tetrallogy of Fallot
3. Persistent truncus arteriosus

Question 16

Aortic and pulmonary valves derive from

Answer 16

Endocardial cushions of outflow tract

Question 17

Mitral and tricuspid valves derive from

Answer 17

Fused endocardial cushions of the AV canal

Question 18

Example of displaced valve

Answer 18

Ebstein anomaly

Question 19

Umbilical ______ is high in oxygen

Answer 19

Vein

Question 20

PO2 of umbilical vein. SatO2%

Answer 20

30 mmHg

80% SatO2

Question 21

Shunts in fetal circulation

Answer 21

1. Ductus venosus: umbilical vein-IVC
2. Foramen Ovale: most of O2 from IVC goes to left chamber and aorta: supply head and body
3. Ductus arteriosus: Pulmonary artery has deoxygenated blood from SVC that goes to Descending aorta

Question 22

Ductus arteriosus is due to

Answer 22

High fetal pulmonary artery resistance: due to low O2 tension

Question 23

Helps close PDA

Answer 23

Indometacin (NSAID)

Question 24

Keep PDA open

Answer 24

Prostaglandins E1 and E2: kEEp PDA open

Question 25

Closing of foramen ovale

Answer 25

At birth infant takes breath –> lower resistance in pulmonary artery–> higher pressure in LA>RA

Question 26

Closure of ductus arteriosus

Answer 26

High oxygen: from respiration

Low prostaglandins: from placental separation

Question 27

Remnant of ductus arteriosus

Answer 27

Ligamentum arteriosum

Question 28

Remnant of foramen ovale

Answer 28

Fossa ovalis

Question 29

Remnant of umbilical vein

Answer 29

Round ligament (ligamentum teres hepatis) contained in falciform ligament 
Teres=round

Question 30

Remnant of AllaNtois (urachus)

Answer 30

MediaN umbilical ligament

Question 31

Urachus

Answer 31

Part of allantoic duct between blader and umbilicus

Question 32

Remnant of notochord

Answer 32

Nucleus pulposus