206 Heart Development

sinus venarum

crista terminalis

identify the structure

septal defects

what are the most common heart defects?

mesoderm

the heart and its components form form what embryonic layer?

lateral

what part of the mesoderm gives rise to the heart and its compnents?

fibrous pericardium

the somatic layer of the lateral plate of the mesoderm will give rise to the:

endocardium and myocardium (the heart organ)

the visceral layer (splanchnic) of the lateral plate of the mesoderm will give rise to the:

pericardial cavity

The intraembryonic coelom between the two layers will form the:

neck

the heart develops first in the ______ then moves to the thorax

dorsal mesocardium

Prior to heart looping to form the 4-chambered heart, what must be removed?

dorsal mesocardium

the tissue from which the heart tube is suspended:

transverse pericardial sinus

the breakdown of the dorsal mesocardium results in what formation?

vasculogenesis

formation of blood islands, dorsal aortae:

myogenesis

Cardiac myoblast induction, formation of myocardium, heart tube:

cranial

which end of the embryo does the heart develop?

right

in which direction does heart looping occur:

situs inversus totalis

defective ciliopathy can lead to what as the heart develops?

vitelline veins

these extraembryonic circuits run from the yolk sac:

vitelline veins

these become incorporated into the liver as hepatic sinusoids

umbilical veins

these extraembryonic circuits run from the placenta:

sinus venosus

the region where the veins come together to enter the common atrium is called:

coronary sinus

The left sinus horn will become the:

left sinus horn

the coronary sinus arrises from what fetal structure?

left umbilical vein

what vein will persist through development, bringing maternal blood to the fetus

ductus venosus

passage for the left umbilical vein to pass through the liver to the heart?

right cardinal v.

the SVC arises from what fetal structure?

right sinus horn

what fetal structure is incorporated into the wall of the atria?

right sinus horn

what fetal structure becomes the sinus vernarum

crista terminalis

what structure separates the sinus vernarum and pectinate muscles?

intussusception

incorporation of sinus venosus wall into both atria:

septum intermedium

The two atrioventricular canals are separated by endocardial cushion tissue known as the:

ostium primum

Complete fusion at the septum intermedium does not initially occur, however, yielding a persistent opening known as the:

septum primum

Atrial septation begins with growth of the _______ from the atrial roof toward the septum intermedium.

apoptosis

the ostium secundum, forms by:

foramen ovale

The remaining exposed portion of the septum primum will form the entrance to the:

muscular ventricular septum

In ventricular septation, myocardial growth forms the:

membranous septum

In ventricular septation, endocardial cushion tissue growth forms the

ascending aorta
pulmonary trunk

the conotruncus develops into what two structures?

conotruncus

the ascending aorta and pulmonary trunk arise from what embryonic structure?

conus cordis and truncus arteriosus

wha structures make up the conotruncus?

neural crest

cells from the ______ contribute to the formation of the conotruncal septation

transposition of the great vessels

If the spiraling does not happen, a defect known as ____________ occurs, where the left ventricle empties into the pulmonary trunk and the right ventricle empties into the aorta.

persistent truncus arteriosus

Failure of the two septa to completely divide the aorticopulmonary septum results in a defect known as ____________.This common trunk allows mixing of oxygenated and unoxygenated blood to occur.

tetralogy of Fallot

Anterior displacement of the aorticopulmonary septum results in: a) unequal division of the common tube b) the resultant failure of the aorticopulmonary septum to meet with the interventricular membranous septum results in a ventricular septal defect; c) the widened ascending aorta thus overrides the two ventricles resulting in a mixing of oxygenated and unoxygenated blood:

week 3

folding of the heart tube, beating commences when?

week 4

septum formation happened when?

week 4

valve formation happens when?