3-G Heart Development Flashcards
What happens during the migration and carivation part of the development?
cardiogenic mass cavitates, forming two parallel tubes that fuse into a single heart tube, blood flowing through sinus venous, primitive ventricle, primitieve atrium, conus cordus and trncus arteriosus
What happens during the Bending and Folding stage of heart development?
the heart grows within the constricting pericardial sac, which causes it to fold in places that have slower growth in diameter: the atrium moves caudally to cranially and slightly to the left; the ventricle moves anteriorly, caudally and to the right
Does the pattern of blood in the heart change after folding?
No, the pattern of flow still flows through the same cardiac tube.
What tissue growth contributes to the septation of the AV canal?
growth of the endocardial cushions
The septation fo the atrioventricular canal creates what two cavities?
atria and ventricles, creating an H shaped hole between the two cavities because the endcardial cushions are growing
The separation of the right and left atrium leads to the creation of which two embryonic septum?
septum primum and septum secundum
Describe the direction the septum primum grows as it forms.
septum primum grows down from the cranial end of the common atrium
Describe the two holes in the septum primum
the ostium primum closes as the osteium secunda is formed (via cell death)
Describe the position and substance of the septum secundum
septum segundum is positioned to the right side (growing downward) of the septum primum and is more rigid and thick thatn the septum primum
Name the hole in the septum secundum
foramen ovale
What causes blood to flow from the right to left atria once the septum are formed.
high pressure in the right and low pressure in the left atrium cause the septum primum to pushed aside when blood travels through
Describe the four components of the interventricular septum
the right and left trunconal ridges, the muscular interventricular septum and a portions of the inferior endocardial cushion
What can be seen in the adult of the spot where all the parts of the ventricular septum joined?
the membranous part of the interventricular septum
Common outflow tracts are subdivided into which vessels
the pulmonary trunk and the aorta
Common out flow tracts include what former parts of the embryonic heart?
the truncus arteriosus and the conus cordis
What forms the aorticopulmonary septa?
Truncoconal ridges
Describe the septum that forms to divide the pulmonary trunk and aorta
spiral septum, tracts of outflow cross as they exit the heart
In the adult, the aorta located in what position in relation to the pulmonary trunk?
anterior
What does the umbilical vein connect?
placenta to liver, delivering oxygenated blood
Where is the ductus venosus located?
located in the liver, it acts as a bypass of the liver directly to the inferior vena cava
What is the function of the foramen ovale?
shunts blood between the right and left atrium
What embryonic circulatory elements does the umbilical artery connect?
carries unoxygenated blood from the internal iliac arteries to the placenta
What structures does the ductus arteriosus connect?
the pulmonary trunk and the aorta in order to bypass the fetal lungs
Because oxygenated and non oxygenated blood mixes, what is a characteristic of oxygen carrying capability of the embryo that helps to compensate?
fetal hemoglobin can cary 20-30 more oxygen than maternal blood due to increased oxygen affinity
Define major circulation
circuit of blood coming from the placenta and going to the body
Define minor circulation
the pulmonary circuit, until the infant takes first breathes the collapsed capillary beds offer a lot of resistence in this circuit
The common outflow tract is subdivided into the pulmonary trunk and the aorta by the right and left _______ ________
truncoconal ridges, these ridges form in a spiral to form the aorticopulmonary /spiral septum which reaches down to meed the muscular portion of the intervetnricular septum
The inter ventricular septum is formed from four elements: ?
right and left truncoconal ridges, muscular inter ventricular septum and a portion of the inferior endocardial cushion
In fetal circulation, which has greater O2 content, the superior or inferior vena cava?
Inferior, it is carrying oxygenated blood from the umbilical veins, while the superior is carrying blood returning only from the systemic circulation
What is probe patency (concerning the heart)
another name for the condition when the foramen ovale does not close completely (rarely symptomatic because higher pressure in the left atrium prevents blood flow)
Upon birth, which direction does blood flow through the ductus arteriosum?
from the aorta to the pulmonary trunk
Non-cyanotic malformations result in ____ to ______ shunt of blood.
left to right; they include ventricular septal defects and atrial septal defects
Cyanotic malformations result in a _____ to _____ shunt
right to left; these include patent ductus arteriosus, transposition of the great vessels, persistent truncus arteriosus, tetralogy of fallot (ventricular septal defect, overriding aorta, pulmonary stenosis and right ventricular hypertrophy
