Cardiovascular Embryo Flashcards
What derives from neuroextoderm (neural crest) with respect to the heart
aorticopulmonary septum
What derives from Mesoderm (lateral) with respect to the heart
blood cells
cardiovascular system
Muscles and connective tissue of heart
serous membranes of percardial cavity
Where do blood vessels initially form
extraembryonic mesoderm of umbilical vesicle, connecting stalk, and chorion
Why does blood vessel and heart formation occur
simple diffusion of oxygen and nutrive materials cant supply rapid growth of embryo
Where do the primordial heart and great vessels begin to differentiate
cardiogenic area (horshoe shaped area cranially lateral to neural plate)
What is the first appearance of the heart and what do they cannalize to form
Angioblastic cords
cannalize to form endocardial heart tubes
What forms the primitive heart tube
Fusion of the endocardial heart tubes
What does the primitive heart tube develop into
endocardium
What are the dilations and constrictions of the heart tube from superior to inferior
Truncus arteriosus Bulbus cordis ventricle atrium sinus venosus
What gives rise to the arteries suplying the pharyngeal arches
truncus arteriosus
What section of the elongating heart tube recieves the veins of the embryo umbilical vesicle and placenta
Sinus venosus
Which 2 sections of the elongating heart tube grow faster and why
Bulbus cordis and ventricle
truncus aretiousus and sinus venosus are fixed in the pharyngeal arches and septum transversum respectively
What develops into the Myocardium and Epicardium
splanchic mesoderm surrounding the primitve heart tube and pericardial cavity
Where do contractions begin when the heart first starts to beat
sunus venosus (initially uncoordinated)
what first forms the partiioning of the atrioventricular canal and what does it develop from
Endocardial cushions on the dorsal and ventral walls
develops from induction of cardiac jelly (secreted by developing myocardium)
When does the heart first begin to beat
begining of 4th week
What is the first tissue that seperates the atrium called and where does it originate
septum primum
superoposterior wall
What is the foramen of the septum primum that is a part of the valve action
Foramen secundum
Where is the first opening of the septum primum located and what is it called
caudal ventral before closing
foramen primum
what is the second layer of tissue dividing the atrium and where does it originate
Roof of atrium just right of foramen secundum
septum secundum
Which of the artial dividers is thicker
septum secundum
what is the opening of the septum secundum and where is it located
foramen ovale
near floor of right atrium
describe the conditions necessary and path of blood trough the valve of the foramen ovale
pressure in right greater than left atrium
enters through floor of right atrium through froramen ovale
exits through foramen secundum in ceiling of left atrium
What 3 veins does the sinus venosus recieve and where are they from
cardinal: embryo
vitelline: umbilical vesicle
umbilical: placenta
What are the lateral expansions of the siuns venosus and when do they develop
Left and right horns
during bulboventricular loop folding
Which horn of the sinus venosus becomes enlarged and why, and what happens to the other horn
Righ horn becomes enlarged
divertion of blood flow to the right side (oblique anastomosis from anterior cardinal veins to right horn and degeneration of umbilical and vitelline veins on left side)
Left becomes coronary sinsus
What eventually becomes the coronary sinus
Left horn of the sinus venosus
What forms the Sinus venarum of the right atrium
The joining of the right horn of the sinus venosus with the right atrium
What portions of the right atrium are derived from primitive right atrium
the trabeculated surface of the right atrium and the right aruicle (also trabeculated)
What forms the smooth wall of the left atrium
incorporation of the 4 branches of the primary pulmonary vein
Once the left atrium merges with the branches of the primordial pulmonary vein what happens to the primitive left atrium
It is displaced anteriorly and to the left
becomes left auricle
What begins the partitioning of the ventricles
growth of the muscular interventricular septum
What is the halt in interventricular septum growth called and where does it appear
interventricualr foramen
just before the fused endocardial cushions
What closes the interventricular foramen
proliferation of tissue from the right side of the endocardial cushions and merging of that memranous interventricular septum with the aorticopulmonary septum