What are the precursor cells for the cardio system?
angioblasts or hmangioblasts; mesenchyme cells within extraembronic and intraembryonic mesoderm
What is a blood island?
aggregates of angioblasts, where they differntiate into endothelial and hemoatopietic stem cells
When are blood islands first observed?
day 17-18 in wall of yolk sac
What is the primary heart derived ffrom?
splanchnic mesoderm, u shaped found cardiogenic cresecent aka primary heart field
Cells from cardiogenic crest migrate into space between foregut endoderm and cardiogenic crest form what?
endothelial plexusq
Remodeling of endothelial plexus results in what?
inner tube with endothelium
What is the primitive heart tumbe?
initial linear heart tube; that is the primitve left ventricle
What is the secondary heart field?
an additional source of cardiac progenitor cells that contribute to the bulbus cordis(primitve right ventricle) outflow region and the primordial atrium the atrioventricular canl and the sinus venosus
What is cardiac endothelium?
the epithelium lining of the lumen of the heart
What is the mycoardium in simple tubular heart?
the outer epithelial tube
What is cardiac jelly?
between endocardium and myocardium; in AVcanal and outflow region.
What are the swellings in teh cardiac jelly?
endocardial cushions; either bulbar or conotruncal ridges
What ist he epicardium?
derived from proepicardial organ a cluster of coelomic epithelial cells adjacent to sinus venosus
underlying visceral pericardium; also contribute to formation of coronary vessels
Venous inflwo at the venous pole results in what?
several venous channels enter the sinus venosus of the primitive heart; umbilical veins contain placental blood
vitelline veins
common cardinal veins
What do vitelline veins do
contain oxygen poor blood from gut
What do common cardinal veins do?
contain oxygen poor blood from head and trunk
Which direction does the heart loop to?
the heart almost always loops to the right
A lack of proper looping results in what?
failure of complete looping results in retention of embryonic pattern of blood flow through the heart; double inlet left ventricle and double outlet right ventricle
What days does blood flow occur?
begins at day 20-22 and by day 26 becomes unidirectional
What forms the definitve right atrium?
primordial right atriuma dn portions of the sinus venosus
What does the proximal portion of the right anterior cardinal vein become?
superior vena cava
What becomes the terminal segment of the inferior vena cava?
cranial portion of the right vitelline vein
What is hte ridge of tissue to form the junction between smootha nd trabeculate portions of definitvie right atrium?
crista terminalis
What is teh coronary sinus derived from?
left sinus venosus
What is derived from teh right sinus valve?
crista terminalis
valve of the IVC
valve of CS
What is the smooth area of right atrium derived from?
absorbed right SV
What is the Inferior vena cava (terminal segment) derived form?
right vitelline vein
What is the superior vena cava derived from?
right common cardinal vein
What is the appendage (trabeculate poriton derived from?
primordial atrium
What is teh wall of the definitve left atrium foremd from
absored pulmonary veins
Why cant teh simple AV canal be simmply divided in development?
there is no connection between the right atrium and right ventricle with the simple av canal
How is the connection between the right atriuma and right ventricle made?
remodeling changes along inner curvature of heart, endocardial tissue is replace with cardiac muscle, thinning the heart wall and causing right ward expansion of the common av canal
What are bulbar ridges?
expansion of cardiac jelly, populated with cardiac mesenchyme
Fusion of thesuperior and inferior endocardial cushions from what?
septum intermedium
What does the cardiac mesenchye in hte mature hearrt?
valve leaflets, as well as chordae tenidnae and cardiac skeleton
At what time does cardiac muscle form the IVS?
24-26
When does the membranous portion of IVS come from?
from cushion tissue of bulbar ridges adn inferior endocardial cushion
What intraventicular communication is never closed?
primary interventricular ccommunication; becomes aortic vestibule
What are the specilalized requirements of the interartrial septum?/
must seperate two atria
must allow right to left shunting during fetal life
must provide for only one way shunting
What days does septation of common primordial atrium occur?
26-28
What are the inferior or leading edge of PAS coated with?
mesenchyme cap;
What is the superior interarterila fold?
interartrial muscular ridge on roof of common atrium to right of PAS- forms septum to form oval foramen
What prevents left to right flow of blood in atria of fetus?
septum primum
What forms teh inlet of right and left ventricles?
AV canal
What forms the apical trabeculated portions of ventricles?
primitve ventricules
What forms the outlets of the right and left ventricles(smooth portion?
proximal outflow region
What forms pulmonary and aortic valves and part of the roots of these trunks?
distal outflow region
What forms parts of pumlonary and aortic roots?
aortic sac
What seperates teh outflow region into two sets of channels?
conotruncal septum; formed by opposing riges within each poriton–bulbar ridges
At what week is heart completel divided?
7th-8th week
What heart defects create a left to right shunt?
ventricular septal defect
atrial septal defect
patent ductus arteriousus
What are the blue baby, “cyanotic” congenital defects?
Tetralogy of Fallot
Transposition of Great Vessels
Truncus Arteriousus
Pulmonary Stenosis/Atresia
What congenital defects cause left heart obstrution?
occur from obstruction of blood flow out of the left ventricle or into them.
What is teh msot common major congenital heart defect?
ventricular septal defect
Where are 90% of ventricular septal defects?
perimembranous
