cardiac embryology

Question 1

the two cardiogenic areas flanking the primitive streak have different growth potential, how does this relate to the final anatomy

Answer 1

situs solitus vs situs inversus

Question 2

what are the four primitive dilations of the heart

Answer 2

bulbus cordis
primitive ventricle
primitive atrium
sinus venosus

Question 3

what are the proximal and distal portions of the bulbus cordis called

Answer 3

distally the arterial end is the truncus arteriosus, and proximally the conus

Question 4

at the venous end of the primitive tube the sinus venosus has two what

Answer 4

a right and left horn

Question 5

each right and left horn of the sinus venosus receives what three veins

Answer 5

the vitelline vein (yolk sac), the umbilical vein (placenta) and the common cardinal vein (body wall)

Question 6

fate of the truncus arteriosus

Answer 6

ascending aorta and pulmonary trunk

Question 7

proximal portion of the bulbus cordis

Answer 7

conus that gets absorbed into the primitive ventricle

Question 8

primitive ventricle

Answer 8

LV and RV

Question 9

primitive atrium fate

Answer 9

RA and LA

Question 10

sinus venosus fate

Answer 10

right horn into the right atrium, left horn regresses to form part of the coronary sinus

Question 11

after the septum primum comes down and joins the AV cushions on what side does the second partition come down to create the flap valve of trhe foramen ovale

Answer 11

left

Question 12

what is the smooth portion of the RA that originated from the sinus venosus

Answer 12

sinus venarum

Question 13

from what structure does the IVC form

Answer 13

right vitelline vein

Question 14

from what structure does the SVC form

Answer 14

right common cardinal vein

Question 15

The right venous valve of the sinus venosus forms what structures in the RA (3)

Answer 15

Crista terminalis
Eustachian valve
Thebesian valve

Question 16

at 30 days gestatation the LA eventrates out to create a common pulmonary vein, this joins the _____ of the lungs formerly draining into the systemic circulation

Answer 16

pulmonary venous plexus

Question 17

The septum intermedium from the proliferation of the AV cushions contribute to which valve leaflets

Answer 17

the septal leaflets of the tricuspid valve and the anterior leaflet of the mitral valve

Question 18

the conus develops into both outflow tracts

Answer 18

true

Question 19

normal right looping is D or L

Answer 19

D

Question 20

initially one primitive ventricle has connections based on right or left half, which side connects to the outflow tract and which side to the primitive atrium

Answer 20

right to the outflow tract and left to the atrium

Question 21

from where does the primitive ventricular septum arise

Answer 21

the floor of the ventricle

Question 22

the conal septum comes from what

Answer 22

bulbar ridges arising in the floor of the conical portion of the bulboventricular cavity give rise to the bulbar septum and grows downward to meet the primitive septum

Question 23

the gap between the conal septum and the primitive ventricular septum is filled by what

Answer 23

proliferation of tissue from the AV cushions

Question 24

truncus splitting occurs in its right left sequence because of what

Answer 24

spiral growth of the septum from right and left truncal swellings

Question 25

fate of 1st arch

Answer 25

maxillary artery

Question 26

fate of 2nd arch

Answer 26

stapedial artery

Question 27

fate of 3rd arch

Answer 27

common and internal carotids

Question 28

fate of 4th arch

Answer 28

subclavian on the right, distal arch on the left

Question 29

fate of 5th arch

Answer 29

disappers

Question 30

fate of 6th arch

Answer 30

PA, ductus and artery to developing lung buds

Question 31

fate of 7th cervical intersegmental artery

Answer 31

left subclavian

Question 32

Van Praagh visceroatrial relationship

Answer 32

S, normal, I inverted, A ambiguous

Question 33

Van Praagh Ventricular Loop

Answer 33

D : RV and thus tricuspid on Right, L: RV and thus tricuspid on Left, X: indeterminate

Question 34

Van Praagh Great arteries

Answer 34

S: anterior and leftward PA I: anterior and rightward PA D: posterior and leftward PA L: posterior and rightward PA

Question 35

which two shifts must occur correctly for normal looping and final ventricular morphology

Answer 35

rightward shift of the AV canal and leftward shift of the conus with disappearance of the bulboventricular flange

Question 36

Failure of establishment of connection between left aortic bud and the epicardial arterial plexus.

Answer 36

ALCAPA

Question 37

Incomplete development of spiral septum

Answer 37

AP window

Question 38

Defect in AV cushion contribution to formation of anterior mitral valve

Answer 38

Cleft mitral valve

Question 39

Flow theory: Blood flow through cardiac chambers and great arteries during fetal life determines their size. Coarctation occurs as a consequence of lack of blood flow across aortic isthmus (either because of VSD or left-sided obstructive lesions). Ductal sling theory (Skoda): Abnormal extension of contractile ductal tissue into the aorta. Contraction and fibrosis of this tissue at time of ductal closure leads to coarctation

Answer 39

Coarctation of the aorta

Question 40

Failure of contribution of AV cushion towards formation of atrial and ventricular septa

Answer 40

Common AV canal

Question 41

Common pulmonary vein gets obliterated after pulmonary systemic connections have disappeared.

Answer 41

Common pulmonary | venous atresia

Question 42

Severe lack of ventricular septation most likely caused by total absence of both primitive ventricular septum and component of AV cushion

Answer 42

Common ventricle

Question 43

Failure of normal development of cusps, which results in primitive gelatinous masses guarding aortic opening

Answer 43

Congenital aortic | stenosis

Question 44

Abnormal connection between the common pulmonary vein and the LA

Answer 44

Cor triatriatum

Question 45

Persistence of the right venous valve, which results in membranous obstruction of the tricuspid valve, RVOT or IVC.

Answer 45

Cor triatriatum dexter

Question 46

Reverse looping of the heart tube (l loop rather than d loop) with malseptation of truncus resulting in both AV and VA discordance.

Answer 46

Corrected transposition | l-TGA

Question 47

Failure of septum to spiral in usual fashion, which results in ventriculoarterial discordance. Alternative theory: underdevelopment of subpulmonary conus resulting in pulmonary mitral continuity (Van Praagh)

Answer 47

d-TGA

Question 48

V Persistence of primitive arrangement where both AV valves empty into LV

Answer 48

DILV

Question 49

Rightward shifting of AV canal exceeds normal shifting resulting in both AV valves emptying into RV.

Answer 49

DIRV

Question 50

Leftward shifting of conus exceeds the normal shifting leading to inclusion of both conal derivatives into LVOT.

Answer 50

DOLV

Question 51

Persistence of primitive arrangement where RV empties into both outlets. Abnormality of spiral septation such that aorta becomes dextroposed. This is greater dextroposition than seen in TOF but lesser than TGA

Answer 51

DORV

Question 52

Failure of delamination of the septal and posterior leaflets of the tricuspid valve resulting in downward displacement of these leaflets.

Answer 52

Ebstein’s anomaly

Question 53

Defect in AV cushion contribution to septal component of tricuspid valve, which results in LV to RA communication

Answer 53

Gerbode defect

Question 54

Leftward displacement of septum primum deflects usual volume of blood away from the left side of the heart, which leads to its underdevelopment Alternative theories: 1) Premature narrowing of foramen ovale, which leads to faulty transfer of blood from IVC to LA. 2) Severe underdevelopment of LVOT, which leads to altered flow pattern in fetus

Answer 54

Hypoplastic left heart | syndrome

Question 55

Failure of normal contribution of AV cushion towards formation of ventricular septum

Answer 55

Inlet VSD

Question 56

Failure of normal fusion between the various segments. Type depends upon level of failure of fusion

Answer 56

Interrupted aortic arch

Question 57

Failure of septum primum to reach the AV cushions. | Alternate theory: Defective formation of AV cushions

Answer 57

Ostium primum defect

Question 58

Persistence of oblique valvular passage between septum primum and secundum

Answer 58

PFO

Question 59

Failure of pulmonary valve leaflets to open resulting in decreased flow through the tricuspid valve and RV and consequent hypoplasia. Variable degree of RV hypoplasia depending on the stage at which fault occurs.

Answer 59

Pulmonary atresia / | intact ventricular septum

Question 60

Abnormal connection between the individual pulmonary veins and the common pulmonary vein

Answer 60

Pulmonary vein stenosis

Question 61

Premature narrowing of foramen ovale or improper angulation of limbus leads to hypoplasia of left-sided heart structures (flow theory)

Answer 61

Shone’s complex

Question 62

Malseptation of conal septum with primitive interventricular septum. May be associated with posterior malaligned VSD when conal septum projects into LVOT. Subaortic membrane develops as a result of turbulence in abnormally shaped LVOT.

Answer 62

Subaortic stenosis

Question 63

Failure of the common pulmonary vein to connect to the pulmonary venous plexus of the lung buds

Answer 63

TAPVR

Question 64

Classic theory: Faulty septation of bulbus cordis that results in unequal sized great vessels (i.e., large aorta and small pulmonary trunk). Alternative theory: Underdevelopment of subpulmonary conus with consequent rightward and superior shift of the aortic valve.

Answer 64

TOF

Question 65

Failure of 6th arch arteries to connect with the systemic arteries carried by the lung bud from the primitive foregut and persistence of connections from aorta (AP collaterals). Variable degree of development of true PA depends on stage at which defect sets in.

Answer 65

TOF / pulmonary atresia F

Question 66

Defect between the conal and primitive interventricular septum usually associated with some degree of malalignment.

Answer 66

VSD – Conoventricular

Question 67

Defect of the endocardial AV cushion, most likely the medial cushions

Answer 67

VSD – inlet (type 3)

Question 68

Defect in the primitive interventricular septum

Answer 68

VSD – muscular (type 4)

Question 69

Defect in development of the bulbar septum

Answer 69

VSD – outlet (type 1)

Question 70

Failure of membranous septum to form completely and may occur because of inadequacy of any of the three contributors.

Answer 70

VSD – perimembranous | type 2