Term
| Where is the heart located? |
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Definition
thoracic cavity, midline, LV in left chest
anterior to vertebra, posterior to sternum |
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Term
| Where are the bronchi with respect to the aorta? |
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Definition
| they extend underneath the aortic arch |
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Term
| How are the atria and ventricles oriented with respect to each other? |
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Definition
The atria are superior and posterior to the ventricles
the ventricles are inferior and anterior to the atria |
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Term
| Describe oxygenated blood cycle for adult. |
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Definition
| deoxygenated blood enters the RA via the S and IVC, to the RV then to the pulmonary arteries, to the lungs, back to LA via pulmonary veins, and to LV, and out to systemic circulation |
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Term
| Describe oxygenated blood cycle in a fetus. |
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Definition
| oxygenated blood enters the RA via the S and IVC, then to the LA via foramen ovale as well as the RV then to the pulmonary arteries, to the lungs and aorta via ductus arteriosus, back to LA via pulmonary veins, and to LV, and out to systemic circulation |
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Term
| Name the four heart valves and their location. |
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Definition
Tricuspid valve (Right atrioventricular valve)
Mitral Valve (Left atrioventricular valve)
Pulmonic Valve (Right ventricular valve)
Aortic Valve (Left ventricular valve) |
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Term
| Which are the semilunar valves? |
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Definition
| pulmonic and aortic valves |
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Term
| Where does fertilization take place? |
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Definition
| the ampullary region of the oviduct |
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Term
| How does a zygote receive nutrition and at what stage does this change, and what occurs next? |
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Definition
| diffusion, the morula stage, the blastoceolic cavity forms to aid in diffusion |
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Term
| what fetal cells develop into the placenta? |
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Definition
| syncytiotrophoblast cells |
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Term
| Where do trophoblastic lacunae develop and what are they? |
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Definition
| within the syncytiotrophoblast of the placenta, they are spaces within the placenta that fill with maternal blood to form uteroplacental circulation |
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Term
| what is the uteroplacental circulation composed of? |
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Definition
| syncytiotrophoblast, trophoblastic lacunae, maternal blood, and maternal venules |
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Term
| when is fetal implantation complete and what implications does this have? |
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Definition
| 2 weeks, maternal blood can leak from lacunae out of the abembryonic pole and result in "spotting" therefore, a pregnant woman may not know she is pregnant until 6-7wks of pregnancy |
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Term
| What induces the development of the epiblast? |
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Definition
| signals from the hypoblast |
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Term
| ________ becomes the embryo proper, and _________ becomes part of the placenta. |
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Definition
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Term
| What causes formation of the prochordal plate and what does it later become? |
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Definition
| tight adhesion between epiblast and hypoblast cells, the oropharyngeal membrane (also called buccopharyngeal) |
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Term
| What region does the anterior visceral endoderm become? |
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Definition
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Term
| What divides the embryo into right and left portions as well as anterior and posterior? |
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Definition
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Term
| Where is the prechordal plate locate? |
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Definition
| posterior to the prochordal plate |
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Term
| Cardiac induction begins by what signals and when do they occur? |
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Definition
Wnt's from hypoblast during pre streak
and FGF8 from AVE during ingression stage |
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Term
| Describe how nutrients play a role in orifice development. |
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Definition
| the tight junction between certain cells prevents nutrients from getting between them, this causes the inner cells to die and a cavity forms |
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Term
| What molecule is secreted by the primitive streak and what role does it play? |
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Definition
| retinoic acid, as cells pass through it they are told how to differentiate depending on transit time |
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Term
| Where are the primary and secondary heart fields during development and what do they become? |
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Definition
the cardiogenic mesoderm wraps around the prechordal plate in a horseshoe like configuration
primary is located superiorly and becomes the LV
secondary is located inferiorly and becomes the RV
the horseshoe ends become the atria |
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Term
| Describe the fate of cardiac cells passing through primitive streak. |
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Definition
midline cells become outflow tract (aorta and pulmonary arteries)
whereas cells more laterally become the atria and inflow tracts (veins) |
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Term
| where do the first blood vessels develop in the embryo and how? |
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Definition
the yolk sac (extraembryonic mesoderm)
clusters of cells form blood islands and eventually vacuoles, the outer cells become endothelium and the inner cells slough off and become blood cells |
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Term
| Describe angiogenesis and vasculogenesis. |
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Definition
vasculogenesis - when cells group and coalesce into a tube forming an inner sinus for blood flow (vasculature from anew)
angiogenesis - sprouting of preexisting blood vessels (common in tumors) |
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Term
| What does the splanchnic mesoderm become? |
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Definition
| the circulatory system and gut wall |
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Term
| Describe cephalocaudal folding and the positioning of the cardiac region. |
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Definition
| the embryo grows faster than the yolk sac causing a ventral folding of the embryo, also get lateral folding which brings lateral vasculature to the midline, the cardiac region moves ventrally and inferiorly |
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Term
| where does the innervation for the heart originate and why? |
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Definition
| the cranial and cervical region, because the heart began development there |
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Term
| how is the gut tube formed? |
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Definition
| during cephalocaudal folding the lateral folding of the embryo forms a cavity in the middle |
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Term
| Describe the formation of the heart. |
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Definition
| the joining of the heart tubes forms the endocardial tube, this tube grows inside the pericardial sac forming bulges and looping |
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Term
| Which heart tubes become the atria/ventricles? |
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Definition
the superior tubes form the outflow and ventricles
and the inferior tubes form the inflow and atria |
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Term
| Define truncus arteriosus, sinus venosus, and septum transversum. |
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Definition
| the primitive aorta and pulmonary arteries, superior/inferior vena cava and pulmonary veins, the diaphragm |
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Term
| how does the heart tube fold without pinching? |
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Definition
| cardiac jelly inside the walls |
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Term
| what leads to formation of interatrial septum? |
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Definition
| the truncus arteriosus leaning on the heart causes ballooning on either side of the atria |
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Term
| what structure forms the primary separation between atria and how? |
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Definition
| septum primum, it originates superior-posteriorly and moves inferior-anteriorly |
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Term
| what are the ostium primum and ostium secondum? |
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Definition
| hole formed by the closing of the primary interatrial septum, new hole formed in primary interatrial septum from IVC blood flow |
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Term
| what secondary structure develops separating the atria and how? |
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Definition
| septum secondum, it originates superior-anteriorly and moves inferior-posteriorly |
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Term
| how does blood flow between developing interatrial septum and what future structure does this become? |
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Definition
| obliquely between the ostium of the septum secondum and the ostium secondum of the septum primum, the ostium in the septum secondum becomes the foramen oval |
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Term
| describe how blood flows through foramen ovale and what does it later become? |
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Definition
| the septum primum is thinner than the septum secondum and blood flows through secondum's ostium due to high pressure in the RA, when LA pressure increases at birth the flutter valve seals shut, the fossa ovale |
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Term
| what three sets of veins join to form the sinus venosus and where do they come from? |
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Definition
cardinal - muscles and heart
vitelline - GI
umbilical - placenta |
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Term
| describe intussusception. |
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Definition
| the infolding of blood vessels into an organ such as the heart which allows ballooning out of the heart |
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Term
| closing of what orifice leads to separation of the atria and ventricles and what structure does this later become? |
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Definition
| atrioventricular orifice, the atrioventricular valves due to presence of cardiac skeleton |
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Term
| Describe adherons role in AV valve formation. |
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Definition
| it is a chemical mediator released by epimyocardium that induces the formation of the valves (endocardial cushions) |
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Term
| Describe development of interventricular septum. |
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Definition
| migration of cells between the ventricles forms the primitive interventricular septum, and then expansion of the ventricles contributes to further formation of the septum |
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Term
| Where does the cardiac neural crest originate and what role does it play? |
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Definition
| in the hindbrain, it travels through the neural tube and down to the cardiac region, it leads to spiraling of the trunkus arteriosus and separation of the ventricles |
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Term
| what is the aorticopulmonary septa and what heart structure does it contribute to the formation of? |
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Definition
| also called the spiral septa, it separates the aorta and pulmonary arteries in the trunkus arteriosus, the nonmuscular portion of the interventricular septum |
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Term
| What developmental method divides the aorta from pulmonary trunk? |
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Definition
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Term
| how are AV valves formed and what are their attachments? |
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Definition
| the superior portion of the ventricles thickens called the dense mesenchyme, the inferior portion of the ventricles erodes leaving the valves and attachments, chordae tendineae and papillary muscles |
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Term
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Definition
| dorsal, ventral, 1st, 2nd, 3rd, 4th, 6th |
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Term
| what 3 sources of blood empty into the fetal heart and where do they come from? |
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Definition
vitelline - yolk sac and GI
cardinal - body wall and head
umbilical - placenta |
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Term
| describe significance of fetal vein development. |
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Definition
| the vein structure changes as the supply and demand for the body changes |
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Term
| what are the five vascular shunts in the developing embryo, what do they do, and what do they later become? |
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Definition
umbilical vein - carries oxygenated blood from placenta to fetal heart (ligamentum teres)
umbilical arteries - carries deoxygenated blood from fetal circulation to placenta (medial umbilical ligaments)
ductus venosus - bypasses the liver to the IVC (ligamentum venosum)
foramen ovale - allows blood flow between atria (fossa ovalis)
ductus arteriosus - bypasses pulmonary circulation to aorta (ligamentum arteriosum) |
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Term
| what are the six mechanisms driving cardiovascular development? |
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Definition
| cellular migration, extracellular matrix, hemodynamics, targeted growth, cell death, visceral situs |
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Term
| what cardiac malformations have the highest incidence? |
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Definition
| ventricular (39%) and atrial (10%) septal defects |
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Term
| what occurs in ventrticular septal defect and how is it caused? |
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Definition
| the interventricular separation is not formed allowing form mixing of ventricular blood, the incomplete spiraling of the spiral septa and/or incomplete formation of interventricular septa (85-90% spontaneously close within first year) |
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Term
| what occurs in atrial septal defect and how is it caused? |
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Definition
| mixing of atrial blood, can be caused by perforations in the foramen ovale, or the septum primum wasn’t the right size and the hole never closed |
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Term
| what is coarctation of the aorta, how does it occur, and what bypass is available? |
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Definition
| it is a narrowing of the aorta that can occur either pre or post ductal, due to migration of ductus arteriosus cells into aorta that are programmed to pinch off during development, the internal thoracic artery |
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Term
| what are pulmonary and aortic valvular atresia and what are its affects? |
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Definition
| when the pulmonary or aortic valves are very narrow, the respective ventricle atrophies, the patent ductus arteriosus and foramen ovale remain in both cases |
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Term
| what happens in aortic valvular stenosis? |
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Definition
| the aortic valve is calcified reducing blood flow through the valve, the LV hypertrophies |
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Term
| What four malformations exist in tetralogy of fallot and what are its characteristic presentations? |
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Definition
| pulmonary stenosis, overriding aorta, interventricular septal defect, and RV hypertrophy; coeur en sabot (heart shaped like shoe) and crouching posture, associated with decreased VEGF |
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Term
| What is persistent truncus arteriosus? |
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Definition
| the spiral septum does not complete separation of the truncus arteriosus, there is no separation between ventricles or aorta and pulmonary arteries |
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Term
| What is transposition of great vessels? |
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Definition
| when the spiral septum forms incorrectly and the aorta attaches to the RV and the pulmonary arteries attach to the LV, the ductus arteriosus remains |
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Term
| what malformation can occur due to aberrant cell death? |
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Definition
| muscular ventricular septal defect |
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Term
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Definition
| when the internal organs of the body align on the opposite side, complete is nonsymptomatic, partial can be dangerous |
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