Term
| heart at 20 days of development |
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Definition
| a simple heart tube develops- a peristaltic pump with a venous end and an arterial end. it must fold to create the adult shaped heart |
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Term
| partitioning of the atria |
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Definition
| a partition develops (septum primum) with a little hole called the flexible ostium primum which wants to close off and then we get a second hole bc the baby needs a way to get blood to go from RA to LA. Get second septum (secundom) which is stiff. At birth the blood flows against the flexible 1st septum and then when the gradient changes, it becomes a valve and pushes against the 2nd septum and can then close after birth. The second septum has a gap in it called the foramen ovale. |
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Term
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Definition
| travels over to the right |
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Term
| flow from the right ventricle |
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Definition
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Term
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Definition
| outflow tract needs to spiral (spiral septation) and both the aorta and pulmonary trunk need to be approximately the same size bc they carry the same amount of blood |
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Term
| fetal circulation in early development |
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Definition
| get oxygen and nutrient rich venous blood from the placenta , most of it bypassing the liver and entering the inferior vena cava -> RA -> foramen ovale -> LA so fetal pressure of the right heart is greater than the left heart and so the lungs are collapsed and thoracic pressure is high. most of this oxygen rich blood goes out the aorta, to the brain via the great vessels, and the rest combines with poorly oxygenated blood from the upper body coming through the superior vena cava -> RV -> pulmonary trunk -> ductus arteriorsus -> aorta (pressure in pulmonary trunk > pressure in aorta) -> rest of body (blood going to the lower part of the body is mixed oxygenated and low O2 blood), only small amnt of blood going to lungs |
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Term
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Definition
| pulmonary resistance drops bc the lungs open -> right heart pressure drops bc pressure in lungs is lower -> inc venous return to LA -> changes pressure gradient -> pressure now higher in left heart than right heart -> push in that direction and close foramen ovale -> fuses to become fossa ovalis -> few hrs after birth ductus arteriosus constricts (adult remnant is ligamentum arteriosum) |
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Term
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Definition
| vascular stasis, vascular damage, hypercoagulability, most often in the leg. can develop in ppl on long airplane flights w dehydration |
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Term
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Definition
| when a clot gets trapped in the vascular system |
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Term
| in a pt w/o heart defects where is an embolus from the legs most likely to get lodged? |
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Definition
| in the pulmonary arterial circulation, PE. bc clot travels up and sees larger and larger veins until reaching pulmonary artery then sees smaller and smaller vessels until it gets lodged (bc left heart is greater than right heart goes to lungs) |
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Term
| what happens to someone w a DVT who develops a stroke and also has a small atrial septal defect? |
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Definition
| the embolus will likely still lodge in the pulmonary arterial circulation bc blood is flowing from L -> R through atrial septal defect. Then some of the pulmonary circulation will be blocked off causing an increase in right heart pressure bc RT heart has to beat to a smaller vascular bed -> right heart pressure can now exceed left heart pressure so now the embolism can get to the left heart and then go out to the systemic circulation and could potentially go to the left common carotid artery and cause a stroke |
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Term
| in which way would you expect blood to flow through an atrial septal defect? |
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Definition
| L -> R bc left arterial pressure is higher |
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Term
| Tetralogy of fallot features |
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Definition
| ventricular septal defect, overriding aorta (large and overrides ventricular septum), pulmonary stenosis (narrowed pulmonary trunk), right ventricular hypertrophy |
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Term
| underlying defect of tetralogy of fallot |
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Definition
| mal partitioning of the outflow tract and of the ventricular septum because of a failure of several septa to meet properly and since the pulmonary trunk is narrow and pulmonary pressure is high, in infant, get right ventricular hypertrophy bc RT heart beating into higher vascular resistance. ventricular septal defect is lifesaving bc allows for increased pressure in the rt to be relieved a little by going to left heart |
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Term
| surgery for tetralogy of fallot |
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Definition
| place a graft that enlarges the pulmonary trunk and repair the ventricular septal defect |
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Term
| transposition of the great vessels |
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Definition
| aorticopulmonary septum fails to spiral (impt for carrying aorta to right and pulmonary trunk to left) bc of failure of spiraling, right ventricle leads into aorta and left ventricle leads into pulmonary trunk and get 2 independent circulations with blood returning to the heart without going to the lungs. The foramen ovale and ductus arteriosus need to remain open for the blood to mix. Surgery must be done immediately to save the child |
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Term
| funduscopic examination drugs |
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Definition
| drug of choice within the antimuscarinic is tropicamide (induces mydraisis), not charged so it can affect the eyes, duration of action 15-60 min. also phenylephrine is used, which is your alpha-1 agonist |
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