Flashcards
jan 15th wed
Cards in this deck (29)
- 1Cardiac Tube FormationA bilateral system of contractile blood vessels form a tube, then coalesce at the midline to form a single heart tube (18 - 21 days).
- 2Cardiac Tube Folding— Here, the elongated tube begins to fold and twist over itself due to crowding from a growing cephalic region
the beginning of distinctive regions in the heart tube (3.5 weeks). - 3Cardiac Tube DivisionThe heart is split into two pumps; the right side pumps blood straight to the descending aorta, the left side pumps blood to the cranium and brain (end of 4th week).
- 4Vascular System DevelopmentAs the heart tube becomes regionalized, the more advanced vasculature system is needed to facilitate blood flow throughout the embryo, and to and from the placenta and yolk sac (this occurs throughout development
- 5Embryonic (not tube) FoldingCardiogenic field is found at the rostral end of embryo and along periphery
Central nervous region develops rapidly in cephalid region, pushing cardiogenic field caudally to cervical region, then thorax
The lateral portions of the embryo also fold ventrally (i.e. begin to tuck under embryo)
As this folding continues, the lateral tubes meet ventrally, and fuse to form the heart tube
The caudal aspect of the tube remains bifurcated - 6Cardiac Tube FoldingAs the embryo continues to fold, the heart tube continues to bend and fold
Shaft of the rostral portion shifts ventrally and caudally; the caudal end shifts dorsally and cranially — this puts a zigzag pattern in the heart tube
Combination of tube folding, and differential expansion and contraction of the tube, begins to both shape adult heart regions and place them in adult orientation to one another - 7Cardiac Tube DivisionThe tube is now organized by regions, from cranial to caudal; pulmonary & aortic aa., arterial tracts from ventricles, right ventricle, left ventricle, fused aorta
The next major phase is to further divide these lumen in the cardiac tube (septation) - 8Heart DevelopmentFirst major system to develop in the human embryo; needed because the rapidly developing embryo can not satisfy its nutrient requirements by diffusion alone
- 9Cardiac Tube Formation Sequence of developmentmesenchyme
- 10Embryonic (not tube) FoldingCentral nervous region develops rapidly in cephalid region, pushing cardiogenic field caudally to cervical region, then thorax
The lateral portions of the embryo also fold ventrally (i.e. begin to tuck under embryo)
As this folding continues, the lateral tubes meet ventrally, and fuse to form the heart tube
The caudal aspect of the tube remains bifurcated - 11Cardiogenic field is found atthe rostral end of embryo and along periphery
- 12truncus arteriosusproximal aorta & pulmonary trunk
- 13bulbus (conus) cordisright ventricle/outflow tracts
- 14primitive ventricletrabeculated parts of left ventricle
- 15primitive atriatrabeculated parts of atria
- 16sinus venosussmooth part of right atrium & coronary sinus
- 17As the embryo continues to fold, the heart tube continues to bend and fold Shaft of the rostral portion shiftsventrally and caudally; the caudal end shifts dorsally and cranially
— this puts a zigzag pattern in the heart tube - 18Combination of tube folding, and differential expansion and contraction of the tube, begins toboth shape adult heart regions and place them in adult orientation to one another
- 19The tube is now organized by regions, fromcranial to caudal
pulmonary & aortic aa.,
arterial tracts from ventricles, right ventricle, left ventricle,
fused aorta - 20atrial divison step 1Septum primum forms from roof of the atrial lumen beginning the separation of left and right atria
- 21step 2Closure is not complete, blood continues to flow through the foramen primum, which itself closes, then a foramen secundum forms.
- 22step 3Next, a second septum, the septum secundum parallels the septum primum, it also does not close (foramen ovale
- 23step 4The septum secundum is rigid, and the septum primum forms a flap over it that opens and closes; allowing blood to flow, mostly, one way
- 24step 5Upon birth, pressure from left atrium keeps septum primum closed against the foramen ovale, which ultimately fuses (Fossa Ovalis)
- 25IVC carriesmixed blood; some oxygenated from umbilical vein
- 26SVCcarries low-oxygen blood from brain and upper limbs
- 27Most oxygenated blood from IVC travels toleft atrium, then flows to left ventricle, then through aortic trunk
- 28Low oxygenated blood from SVC travels fromatrium to right ventricle; then out through the pulmonary trunk
- 29Aorta sends blood to thecommon carotid a., then receives blood from the pulmonary trunk via the ductus arteriosus (i.e., the lungs are bypassed)
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- Flashcards on jan 15th wed, created by Shylla T on 13/01/2020.
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- Shylla T
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