Cardiovascular embryology Flashcards
the heart develops from the…
a) ectoderm
b) notochord
c) mesoderm
d) endoderm
C
the splanchnic layer of the lateral plate mesoderm
https://www.youtube.com/watch?v=RjiPx6Xi-68&t=3430s
the cranial aspect of the heart tube is called the…
a) primitive atrium
b) bulbus cordis
c) primitive ventricle
d) truncus arteriosus
D leading to the aortic sac and dorsal aortae
the truncus arteriosus becomes the (pulmonary trunk then) pulmonary arteries and aortic arch
the primitive ventricle becomes the…
a) right ventricle
b) left ventricle
c) left atrium and ventricle
d) right atrium and ventricle
B
endocardial cushions are formed from what type of cells?
a) epithelial cells
b) neural crest cells
c) notochord cells
d) myotome cells
B
they start to form a midline separation (septum intermedium) between the left and right atria and ventricles. it only forms in the middle and doesn’t fully separate them.
endocardial cells come from the septum and make annuli, valves and chordae tendinae to make the mitral and tricuspid valves.
they also make cushions/ ridges in the outflow tracts- in the bulbus chodis and truncus arteriosus
what tissues from the separation between the left and right atria ( more than one)?
a) septum secundum
b) septum primum
c) septum artia
d) septum intermedium
e) septum ovale
A and B join to the septum intermedium.
septum primum goes most of the way and leaves a small ostia (ostium primum) between it and the spetum intermedium. it eventually reaches the septum intermedium but another hole develops higher up (ostium secundum). then a septum secundum tried to block the ostium secundum but doesn’t quite manage (foramen ovale remains). in utero this is fine as the pulmonary circulation isn’t needed. the foramen ovale closes after birth
what hole in the between the primitive atria remains until after birth, then should close?
foramen ovale
what tissues from the separation between the left and right ventricles (more than one)?
a) muscular portion of the interventricular septum
b) fibrous portion of the interventricular septum
c) membraneous portion of the interventricular septum
d) septum tritium
muscular portion of the interventricular septum (from the apex) and membranous portion from the septum intermedium
VSDs usually occur in the membranous portion
what part of the heart tube makes the outflow tracts?
a) primitive atrium
b) bulbus cordis
c) primitive ventricle
d) truncus arteriosus
B (as well as the right ventricle)
the bulbus cordis separates the pulmonary and aortic outflow tracts, the valves are formed then the two tubes split.
the coronary venous sinus develops from the
a) the left sinus horn
b) the right sinus horn
c) umbilical veins
d) vitelline veins
A
the left horn almost completely regresses except this part, the right sinus horn is incorporated in t the right atrium
a VSD is formed because of…
a) o. secundum defect due to excessive resorption of the septum primum
b) most commonly a membranous defect due to failure of fusion of the endocardial cushions
c) o. primum defect due to incomplete fusion of the endocardial cushions
B- most commonly a membranous defect due to failure of fusion of the endocardial cushions
how does an atrial septal defect occur
o. secundum defect due to excessive resorption of the septum primum or inadequate development of the o. secundum
o. primum defect due to incomplete fusion of the endocardial cushions
normal development: Oval foramen closes–> DA closure leads to a rapid increase in pulmonary circulation hence
a rapid increase in LA pressure. Concurrently the loss of placental flow decreases the pressure within the RA. This causes apposition of the septum primum and septum secundum. Constant apposition will lead to fusion of the two septae
a persistent atrioventricular canal occurs due to…
failure of endocardial cushion fusion
what is tetralogy of fallot?
aortic or pulmonary stenosis occurs because of
narrowing of the trunk where it opens from the ventricle or fusion of the semilunar valves, with or without narrowing of the associated vessel
the aortic sac and primitive heart tube is formed from the..
a) ventral aortae
b) dorsal aortiae
a- when they fuse together
what happens to the fifth aortic arch?
a) becomes the descending aorta
b) becomes the pulmonary arteries
c) becomes the maxillary arteries
d) never forms or completely regresses
D
what happens to the first aortic arch?
a) mostly disappears, with a portion becoming the maxillary arteries
b) never forms or completely regresses
c) forms the hyoid and stapedial artery
d) forms the common carotid arteries
A
c- 2nd arch
d- 3rd arch
the 3rd aortic arch becomes the…
a) common and internal and external carotid arteries
b) common and external carotid arteries
c) subclavian arteries
d) never forms or completely regresses
A
the distal portion of the internal carotid artery is form from the dorsal aortae.
the right subclavian artery is formed from which elements
a) right 4th aortic arch
b) left fourth aortic arch
c) right 6th aortic arch
d) right 7th intersegmental artery
e) right 4th intersegmental artery
f) dorsal aorta
A. D. F.
the proximal part from the rt 4th, the distal part from the right dorsal aorta and the 7th intersegmental artery
the normal aortic arch is formed from which aortic arch?
4th aortic arch and left dorsal aorta
the left subclavian artery is formed from what elements?
a) right 4th aortic arch
b) left fourth aortic arch
c) right 6th aortic arch
d) right 7th intersegmental artery
e) left 4th intersegmental artery
f) dorsal aorta
g) left 7th intersegmental artery
G
the brachiocephalic trunk is form from which structure
a) truncus arteriosus
b) aortic sac
c) right fourth aortic arch
d) bulbus cordis
B- the right side of the aortic sac,
the 6th aortic arches form what structures
a) pulmonary arch and distal pulmonary arteries, ductus arteriosus
b) vertebral arteries
c) vertebral ligaments
d) the left forms the aortic arch, the right regresses
A
the right ductus degenerates
what is the most common clinically relevant aortic arch anomaly?
PRAA
can occur with persistent left ligamentum arteriosum to form a VRA
and an aberrant left subclavian artery
the right vitelline artery becomes the… in the adult
celiac and cranial mesenteries arteries
the left degenerates
which vessels form the cranial and caudal vena cava?
crvc- right cranial cardinal vein and right common cardinal vein
cdcv- caudal cardinal vein
the left cranial cardinal vein degenerates and forms an anastomosis with the crvc to give the R and L brachiocephalic veins
the azygous vein forms from the…
supracardinal vein
which vessels form the portal vein
a) vitelline
b) umbilical
c) cardinal
vitelline and the liver sinusoids
the left umbilical vein becomes the falciform ligament, the right degenerates
what forms the ductus venosus
a bypass system between the left umbilical vein, R hepatic vein, and the intrahepatic vitelline veins
The vascular channel that allows fetal blood to pass from the
pulmonary artery to the aorta is known as the:
a. Foramen ovale
b. Ductus arteriosus
c. Ductus venosus
d. Fetal cotyledon
e. Allantois
B
Which of the following fetal blood structures contains blood
with the highest PO2?
a. Aorta
b. Ductus arteriosus
c. Pulmonary artery
d. Left ventricle
e. Umbilical artery
D. this means the heart (via the coronaries) and the brain (via the carotids) get high oxygenated blood flow. after the the ductus arteriosus mixed more desaturated blood in to the mix going caudally in to the abdomen
Which of the following statements about the fetal circulation is true?
a. Right atrial pressure is higher than left atrial pressure
b. Pulmonary vascular resistance is high
c. The placenta receives about 45% of the combined output of both ventricles
d. The output of the right ventricle is greater than that of the left ventricle
e. All the above
e
the ductus venosus forms what in the adult dog
liagmentum venosum
how does the ductus arteriosus close?
increased oxygen in the aorta causes contraction of the muscles via local prostaglandins and bradykinin. Permanent structural changes eventually obliterate the ductus converting into a
fibrous structure. Functionally or anatomically closed in most puppies by 6-8 days of age
