04a: Embryology Flashcards
CVS begins to develop in week (X). (Y) cells migrate through (Z).
X = 3 Y = progenitor heart Z = primitive streak
CVS development: Progenitor heart cells migrate through (X) and into (Y). This forms (Z), the first heart field.
X = primitive streak Y = (splanchnic) lateral plate mesoderm Z = cardiac crescent (cardiogenic region)
The first heart field, aka (X), is (Y)-shaped and forms (rostral/caudal) and (above/below) which key structures?
X = cardiac crescent (or cardiogenic region) Y = crescent
Rostral to neural fold; Above oropharyngeal membrane
During body folding, the (cranial/caudal) portion of first heart field is pulled in (X) direction, to lie below (Y).
Cranial;
X = caudally and ventrally;
Y = foregut
CVS development: It’s during (X) process that R/L sides of first heart field fuse. (Y), key vascular elements (medial/lateral) to first heart field also fuse and form (Z).
X = lateral body folding;
Y = endocardial tubes (L and R)
Within heart field;
Z = primary heart tube
Endocardial heart tubes are immediately surrounded by:
Cardiac jelly
The heart, during formation, is an expanded tube of inner (X) tissue and outer (Y) tissue. The two layers are separated by (Z).
X = endothelial Y = myocardial Z = cardiac jelly
List the sources of cells for developing heart.
- Primary and secondary heart fields
- Cardiac neural (crest) cells
- Proepicardial organ
CVS development: The (X) is formed from migrating cells derived from proepicardial organ, found in region of (Y). The cells migrate and cover the entire (Z).
X = epicardium Y = sinus venosus Z = myocardium
Coronary vessels form from (X) during CVS development.
X = proepicardial sprouts
Cardiac tube takes shape in (X) week, when it undergoes (Y) process and loses symmetry.
X = end of 3rd week Y = dextral looping
Fetal circulation: (X) vessel carries oxygenated blood from (Y) to fetus.
X = umbilical vein Y = placenta
Fetal circulation: most oxygenated blood from placenta flows directly from umbilical (artery/vein) to (X) via which shortcut?
Vein; X = IVC Ductus venosus (in liver)
Fetal circulation: blood travels from IVC to (X) and then most of that blood passes through (Y) into (Z).
X = RA Y = foramen ovale Z = LA
Fetal circulation: Blood from LA primarily came from (X) and then goes to (Y).
X = RA (through foramen ovale) Y = aorta
The ductus arteriosus connects (X) to (Y).
X = pulmonary artery Y = descending aorta
Fetal circulation: The (X) shortcut allows blood from (Y) to bypass fluid-filled and non-functional lungs.
X = ductus arteriosus Y = RV
Heart partitioning: Septa (walls) will form in which space(s)?
- AV canal
- Outflow tract
- Primitive atrium and ventricle
T/F: Events in partitioning of heart happen sequentially.
False - simultaneously
Heart partitioning: development of which structures is critical for AV canal septation?
Endocardial cushions
Heart partitioning: endocardial cushions form in (X) space(s) as expansions of (Y). Which tissue layers are separated from each other?
X = AV canal and outflow tract Y = ECM (cardiac jelly)
Endothelium and myocardium
Heart partitioning: in AV canal, endocardial cushions form from cells derived from (X).
X = endocardium
Heart partitioning: EMT (epithelial to mesenchyme transformation) is seen in formation of (X) structures in (Y) space.
X = endocardial cushions Y = AV canal
Heart partitioning: in outflow tract, endocardial cushions form from cells derived from (X).
X = neural crest cells
Heart partitioning: Endocardial cushions also serve as primitive (X).
X = valves
Heart partitioning: during AV valve formation, (X) hollows out tissue on (atrial/ventricular) surface of (Y).
X = blood flow
Ventricular;
Y = endocardial cushions
AV valve formation: the valve leaflets are derived from (X) along with some (Y)-derived cells.
X = endocardial cushion tissue Y = epicardium
AV valve formation: valves are covered by (X) tissue and connected to (Y) muscles by (Z).
X = endocardium/endothelium Y = papillary Z = chordae tendinae (fibrous CT)
AV valve formation: the structures are sculpted from (X) walls of (atria/ventricles).
X = muscular;
Ventricles
When (dorsal/ventral/medial/lateral) endocardial cushions fuse, what spaces have formed?
Dorsal (inferior) and ventral (superior);
L and R AV canals
Primitive ventricle becomes (X) in adult.
X = LV
Adult atrial septum formation has contribution from fusion of (1/2/3) embryonic septa. List them.
2;
- Primary (septum primium)
- Secondary (septum secundum)
Adult atrial septum formation has contribution from (1/2/3) foramen. List them
2;
- Primary (ostium primum)
- Secondary (ostium secundum)
Septation of atria: Septum primium forms on (ventral/dorsal/medial/lateral) surface of (Y) space and grows toward (Z).
Dorsal;
Y = atrial chamber
Z = AV canal
Septation of atria: the foramen primium is the space between (X) and (Y).
X = caudal edge of septum primium Y = endocardial cushions
Septation of atria: what’s the function of the foramen primium?
Shunt (RA to LA)
T/F: In septation of atria, foramen secundum forms immediately after obliteration of foramen primium.
False - before obliteration
Septation of atria: foramen secundum forms as a result of (X) in (Y) structure.
X = small ruptures Y = septum primium
Septation of atria: what’s the mesenchymal cap?
Edge of septum primium, growing towards endocardial cushions
Septation of atria: septum secundum is (thicker/thinner) than septum primium and forms to the (R/L).
Thicker; R
Septation of atria: foramen primium is filled/closed when..
Septum primium (its dorsal mesenchymal cap) and dorsal mesenchymal protrusion fuse with AV endocardial cushions
Septation of atria: septum secundum is completely closed when…
It’s not! Leaves opening (foramen ovale)
Fetal circulation: blood entering RA and primarily passing to LA passes through which two openings?
- Foramen ovale
2. Foramen secundum
Septation of atria: the valve of (X) opening in secondary septum is actually a portion of (Y).
X = foramen ovale Y = primary septum
After birth, a (rise/fall) in (X) of (Y) chamber will result in closing of foramen ovale by (Z).
Fall;
X = P
Y = RA
Z = valve (primary septum) of foramen ovale presses against opening (secondary septum)
Partitioning of outflow tract: migration of (X) through (Y), to reach developing heart, is critical.
X = neural crest cells Y = pharyngeal apparatus
Partitioning of outflow tract: neural crest cells contribute to which events?
- Conotruncal sepataion
- Tunics of aorta
- Parasympathetic post-gang neurons of heart
Partitioning of outflow tract: initially, the outflow track has (1/2/3) chambers. Further development of this is result of (X) formation.
1;
X = conotruncal cushions/ridges
Partitioning of outflow tract: conotruncal cushions separate (X) and (Y). They’re largely derived from (Z).
X = aortic channel (outflow tract) Y = pulmonary channel (outflow tract) Z = neural crest mesenchyme
Partitioning of outflow tract: The cardiac outflow tract contains proximal (X) and distal (Y) cushions.
X = conal Y = truncal
Partitioning of outflow tract: fusion of (X) must form (Y) in spiral fashion.
X = conotruncal cushions Y = septum
Partitioning of outflow tract: eventually, truncal part divides outflow tract into (X) and (Y).
X = pulmonary trunk Y = aorta
Partitioning of outflow tract: eventually, conal part divides outflow tract into (X) and (Y).
X = LV outlet Y = RV outlet
Septation of ventricles: interventricular septum has (X) and (Y) parts.
X = muscular Y = membranous
Septation of ventricles: interventricular septum is derived from which two cell origins?
- Neural crest
2. Endocardial cushions
Septation of ventricles: muscular portion grows toward (X) and stops just short of its destination to leave (Y) opening.
X = endocardial cushions Y = interventricular foramen
Septation of ventricles: the ventricular septum is completed upon fusion of (rostral/caudal) end of (X).
Caudal;
X = conotruncal septum
