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151 Cards in this Set

  • Front
  • Back
The intricate structure of the heart develops during the first ______ weeks of life.
the heart begins to beat on the ___ day
Starts from ______ rostral to the oral plate, adjacent to the septum transversum.
About day ___, small islands of blood and endothelial tissue begin to differentiate out of the mesoderm. These coalesce into two tubes which fuse into a single tube.
Induction of heart tubes happens when?
week 2-3
Heart begins beating
week 3-4
Heart partitioning happens when?
week 4-6
Great Arteries transform
week 6-7
Completion of valves
happens when?
week 7-8
___ proteins activate mesoderm to form certain gene products that enhance musculoskeletal development.
Expression of ____ genes result in heart induction.
Paired Heart Tubes Develop as a result of overlap between the positive ___ genes and inhibitory ___ genes
Origin of the heart begin _____ days
Gene sequences producing various BMP proteins in the ectoderm overlying the lateral plate interacts with WNT inhibitors to cause lateral peripherial expression of the ___ genes, which induce heart development.
earliest expression of heart development are the _____
blood islands
blood islands are associated with the ________.
septum transversum
the blood islands develop into ______(which is a simple squamous epithelium, similar to endothelium).
The heart begins as TWO ____ , a left and a right one.
Formation of the heart tube begins as the cardiogenic ________ fuse into a presumptive heart
blood spaces
Mesoderm in the developing aortic arches develop into _________, starting with A.A. #1,
branchial arches
at the venous end the mesoderm begins to form a series of veins from a relatively poorly defined mass referred to as the ___________
angioblastic plexus
Cardiogenic mesoderm differentiates into _______ and _______ on the outside of the heart, while the endocardium continues to line the inside of the heart.
cardiac jelly
Neural crest develops into _______ and ________
aortic root
parasympathetic ganglia
The ___________ , and its _________ lining, forms from mesoderm in the area adjacent to the developing heart, as discussed in core embryo.
pericardial cavity mesothelium
Development of the heart occurs in days _____
growth of the neural tube pulls the oral plate and septum transversum first superiorly, then anteriorly until the heart eventually is flipped over 180 degrees (in the sagittal plane) from where it originally was describes the process of _________
Inversion of the heart tube
At about ___ days, the two heart tubes fuse along the midline, starting with the aortic sac and progressing down the conus arterosis, ventricles, and atria.
Bending of the heart tube: The heart will grow faster than its associated pericardial cavity, causing it to bend into a loop. This generally occurs in a ________ direction (when seen facing the anterior surface of the embryo).
As the heart tube, which is suspended by a _________, bends it forms a hole in the ___________. This hole is the transverse sinus. Hense, he transverse sinus forms from the _________.
dorsal mesocardium
dorsal mesocardium
dorsal mesocardium
Systemic arteries shift to the ______ with the development of the aorta
Systemic veins shift to the ____ as the opening for the sinus venosus moves to the right side of the atrium
Partitioning of the Heart occurs days ____.
The _______ separates the atria from the ventricles, provides a central point for the left right separation of the heart chambers
Endocardial Cushion
The Endocardial Cushion contains many cells of ______ origin.
neural crest
The superior & inferior E.C. will fuse on day 42 to become the single _______.
septum intermedium
The fusion of the E.C leaves behind two openings from atria to ventricles, the ________.
atrioventricular canals
The _________ is the original communication between L & R atria. It closes completely
Foramen primum
The ______ closes the foramen primum. Because there must be blood flow from right to left atrium, another hole arises (next).
Septum primum
The __________ is the secondary interatrial passage (essential for allowing blood to get into left atrium, and therefore left ventricle).
Foramen secundum
The _____ forms valve that permits blood to flow only from right atrium to left atrium, not the reverse.
Septum secundum
The ______ is a space within the arch-like opening of the septum secundum; in coronal view, it will sit between septum secundum and endocardial cushion (septum intermedium)
Foramen ovale
The ______________ arises from interventricular septum.
Muscular interventricular septum
There is an _________ between the left and right ventricles during the early (fifth week) development of the heart. This is finally closed over by a complex arrangement (see next).
interventricular foramen
As the septum intermedium and spiral (aorticopulmonary) septum of the truncus come together with the the muscular septum, the first two membranes (septum intermedium & spiral septum) fuse to contribute to the ____________.
Membranous interventricular septum
Valve formation; arises primarily from tissues associated with the developing muscular walls. _________ causes the valvules to develop in conjunction with the chordae tendineae and papillary muscles, all developing simultaneously in a well-choreographed process.
Programmed cell death
Spiral septum derives primarily from ________
neural crest
Mechanism of spiral septation of the bulbus: swellings arise from differential growth of the wall of the bulbus and truncus, which complete a 180 degree turn of a spiral. Around the junction of the truncus and bulbus there are a set of four swellings which will form the basis for later development of the _______and ______ valves.
The spiral septum separates the blood flows in the _____ and _____, eventually not only dividing the tubes down the middle but completely separating the two major arteries, creating two separate tubes where only one existed before.
The spiral septum merges inferiorly with the developing _______, ensuring the vessels are in continuity with the ventricles.
muscular interventricular septum
The spiral nature of the septum is necessitated by the position of the aortic sac and aortic arches, and by the structure of the heart at this stage: i.e., the left ventricles is more or less in ____ , the right ventircle is more or less in _____. The future aorta is posterior and the future pulmonary trunk is anterior
Note that the spiral septum also fuses simultaneously with the _______ in formation of the membraneous interventricular septum.
endocardial cushon (septum intermedium)
Human therapy is theoretically possible, but will require ______
stem cells
When does the heart begin its formation?
When does it begin to beat?
Identify and define the following embryonic regions:
a. Conus Cordis.
b. Trucnus Arteriosis.
c. Bulboventricular loop.
d. Sinus venosis.
e. Coronary sulcus.
f. Endocardial cushon.
g. Septum primum
h. Septum secundum.
i. Foramen primum.
j. Foramen secundum.
k. Bulbar (spiral) septum.
l. Foramen ovale.
m. Cardiac jelly.
Explain how the atria and ventricles separate from one another
. Explain how the right and left atria, and R. and L. ventricles, separate.
What is the function of the foramen ovale the final (fetal) pattern of blood flow?
Explain how the bulbar septum fits into this pattern.
Why is the bulbar septum spiral in shape?
Explain how the heart can continue to function while changing from the embryonic to fetal patterns of blood flow.
Explain the development of the smooth-walled portion of the atria as well as the origin of the auricles.
The ________ receives blood from truncus arteriosus, and distributes it to all of the aortic arches.
Aortic sac
The _______ is found in the branchial arches, sends blood to the dorsal aortae of the head, the left aortic arches to the left dorsal aorta of the head, the right aortic arches to the right dorsal aorta of the head.
Aortic arches
The two (right and left) _______ of the head fuse past the sixth aortic arches to form the single _____ of the body, most of which becomes the descending aorta in the thorax and, farther down, the abdomen.
dorsal aortae
The _____ branch off of the dorsal aorta which segmentally supply parts of the periphery.
Intersegmental arteries
the 7th intersegmental becomes the ______ and parts of the _______.
axillary artery
The _________ supply the yolk sac. Its main branches become celiac, superior mesenteric and inferior mesenteric arteries.
Vitelline arteries
The _______ arise from the internal iliac arteries. All fetal blood going to the placenta arise from the two umbilical arteries.
Umbilical arteries
Arch #1, bilaterally--
Maxillary artery
Arch #2, bilaterally--
Arch #3 bilaterally, along with the more superior portions of the anterior dorsal aortae of the head, become the __________ .
internal carotid arteries
Carotid duct (short part of dorsal aorta)
RIGHT arch #4, along with a segment of the right dorsal aorta of the head and the right 7th intersegmental A., all become the __________. (note relation to R. recurrent laryngeal N.)
Right subclavian artery
A portion of the RIGHT aortic sac becomes the _________.
Right brachiocephalic artery
A portion of the RIGHT dorsal aorta of the head, which is distal to the 7th intersegmental A
lost without any trace
LEFT arch #4, in conjunction with a portion of the Left aortic sac and the left dorsal aorta of the head all contribute to the _________. (note relationship to L. recurrent laryngeal N.)
Arch of the aorta
LEFT seventh intersegmental artery; this is the only vessel contributing to the ___________ and parts of the L. Axillary A
Left Subclavian artery
Arch #6 (bilaterally) contributes to ______ and (on the left side only) _______.
Pulmonary arteries
ductus arteriosus
The __________ is an important structure in the fetus, which allows most of the blood pumped by the right ventricle to by-pass the lungs and instead enter the descending aorta.
ductus arteriorus
On the right side only, the part of the 6th arch which connects to the R. dorsal aorta of the head _________.
___________ initially supplies the yolk sac.
Vitelline artery
Vitelline artery branches supply the developing gut and eventually become the ________,_______and _______ arteries.
Celiac, superior and inferior mesenteric
_________ supply blood to the placenta via the umbilicus
Umbilical arteries
Eventually, around the umbilical arteries, develop the ________ and __________.
internal and external iliac arteries
All blood returning from the heart passes first through a ____ or _____ , which joins a common sinus venosus before emptying into the atrium.
left or right sinal horn
A series of _________ develop early on, which quickly develops connections to all of the major veins.
venous antioblastic plexuses
______ drain the yolk sac, where the first blood cells begin formation around the fourth week.
Vitelline veins
drain the placenta, supplying “oxygenated” blood to the fetus.
Umbilical veins
________ are the veins of the embryo proper, draining all parts of the embryo to the sinus venosus
Cardinal system of veins
__________ drain the head and what will eventually become parts of the chest.
Anterior cardinal veins
________ drain the posterior body, including the abdomen, pelvis and lower limb. Becomes extensively modified to form supracardinal and subcardinal veins, as the original posterior cardinal vein slowly disappears
Posterior cardinal veins
The anterior and posterior cardinal veins join together to become _______, before they empty into the sinal horn.
common cardinal veins
Shift of systemic venous circulation to the right involves a reduction of the left sinal horn to form the ________
coronary sinus
There is a shift of the opening of the _______ to the right side of the common atrium, just before the interatrial septum begins to develop.
sinus venosus
. The wall of the sinus venosus is smooth, creating a _________, which has a smooth wall, as opposed to the original atrium wall, which has pectinate muscles in it.
sinus venerium
Superior vena cava from ______ and ________
R. common
anterior cardinal
L. brachiocephalic v. anastamoses through developing mediastinum to R. brachiocephalic to join ______
Note that _______ gives rise to the Azygos system.
R. posterior cardinal V
Also note the remnants of the _______ will give rise to a ligamentous remnant called the ‘ligament of the left superior vena cava.’
L. anterior cardinal V.
________ pierces diaphragm to form terminal segment of inferior vena cava.
R. vitelline vein
IVS then anastomoses to _____.
cardinal veins
Note that hepatic portal v. arises from the vitelline system, and the L. umbilical V. anastomoses with portal vein to form a ________ that will empty into the IVC and which will leave ligamentous remnants that will be discussed further with the liver.
ductus venosus
The most highly oxygenated blood enters via the _______, which passes through the ductus venosus before it is mixed with the blood in the inferior vena cava. Already, the oxygenation is compromised.
umbilical vein
Much (actually, only about half) of the blood from the IVC passes through the ______ and ________ to the left atrium. This is accomplished by the placement of the IVC (pointed medially) and pressure relationships in the L. and R. atria. This is pumped via the aorta to the head and upper limbs.
foramen ovale

foramen secundum
Blood from the superior vena cava mixes with the rest of the blood from the IVC to be pumped directly into R. Ventricle and from there to the lungs. Because the lungs are too small to receive all this blood, most of it is shunted away to the descending aorta via the _______.
ductus arteriosus
Identify and explain the significance of the following:
Aortic sac.
Truncus arteriosus.
Aortic arches 1-4, 6.
Dorsal paired aortae of the head.
Dorsal aorta of the body.
Intersegmental arteries.
Vitelline A.
Umbilical arteries.
Sinal horns, L. and R.
Umbilical veins.
Vitelline veins.
Cardinal veins (common, anterior, posterior, subcardinal, supracardinal).
Renal anastomosis.
Ductus venosus.
Ductus arteriosus.
Ligamentum arteriosum.
Ligamentum venosum.
What is the pattern of circulation in the normal fetus
What changes take place at birth?
How do these changes take place?
3. Identify the origins of the following:
Aorta (Ascending, arch, descending).
Internal and external carotid arteries.
Brachiocephalic A.
Subclavian AA.
Brachiocephalic veins.
Superior vena cava.
Inferior vena cava.
Hepatic portal veins.
Pulmonary AA and VV.
Azygos V.
Oxygenated blood returns to the embryo via the _______.
umbilical vein
Oxygenated blood returned to the embryo via the umbilical vein can mix with unoxygenated blood from the ____________.
hepatic portal system
Moderately oxygenated blood from IVC is shunted to left atrium via the _______
foramen ovale
unoxygenated blood in SVC is directed to ________
right atrium
Much of the right atrial blood bypasses the lungs; it passes through the ________ to go to the descending aorta (note the head and arm gets the most highly oxygenated blood, and the blood going to the lower part of the body is less well oxygenated).
ductus arteriosus
When the umbilical cord is clamped, blood ceases to flow through the umbilical V.; the ________ will then close down.
ductus venosus
When the umbilical cord is clamped, blood ceases to flow through the umbilical V.; the ductus venosus will then close down. This causes a decrease in _________ ; so the foramen ovale closes.
right atrial pressure
The concomitant increase in pulmonary blood flow causes increased blood flow to lungs, and therefore to ________
L. atrium
With the lungs functioning, the increase in blood oxygen stimulates the ________ to close, establishing the adult circulatory pattern.
ductus arteriosus
reverse rotation
Ectopia cordis
heart external to body
Atrial septal defect
hole” between the two atria
(Secundum type defect). Either septum secundum too small or foramen secundum too large. Large holes create much mixing; small hole has less noise, less mixing, but pressure from L. atrium may force blood through too fast, creating problems in atrial wall later.
Patent foramen ovale
(patent foramen primum; failure of septum primum to fuse with endocardial cushion)
Endocardial cushion defect with primum type defect.
Common atrium
no septa whatsoeve
incomplete absorption into R. atrium. Associated with defective pulmonary veins.
Sinus venosus defect
(most common). Hole in membraneous interventricular septum.
Membranous septal defect
‘swiss cheese’ defect, many small holes in trabecular carneae.
Muscular septal defect
Very rare; (3 chambered heart).
absence of septum
Aorta arises from R. Ventricle, Pulmonary trunk from left.
Transposition of great vessels
Aorta and pulmonary trunk do not separate, complete mixing of blood.
Persistent truncus arteriosus.
Unequal division of great vessels.
Aortic or pulmonary stenosis.
Tetralogy of Fallot: Aortic or pulmonary stenosis.
Narrowing of pulmonary valve; undrelying cause of rest of problems.
Tetralogy of Fallot: Ventricular septal defect
Needed to shunt blood to aorta
Tetralogy of Fallot: Over riding aorta.
Sits over interventricular septum
Tetralogy of Fallot: Hypertrophy of right ventricle.
Response to increased workload.
Aortic coarctation
narrowing of aorta
coarctation proximal to ductus arteriosis.
Coarctation distal to ductus arteriosis
(connection or R. dorsal aorta of head to dorsal aorta of body does not involute: aortic arch surrounds esophagus)
Double aortic arch.
(Aortic arch from R. side, goes between esophagus and vertebra).
Retroesophageal aortic arch.
(ductus arteriosus patent into childhood or even adulthood).
Patent ductus arteriosis.
(second IVC following the L. Common Cardinal into coronary sinus)
Double superior vena cava.
(IVC empties into coronary sinus on left, not found on right)
Left SVC.
(IVC blood joins azygos blood flow into SVC).
Absence of hepatic segment of IVC.
(two IVC’s surrounding Abdominal aorta).
Double IVC.
(one pulmonary V. empties into SVC).
Partially anomalous venous return.
Describe which developmental process didn’t work properly in the following malformations:
Primum type defect.
Pulmonary stenosis.
Aortic stenosis
Tetralogy of Fallot.
Persistent truncus arterosus.
Transposition of the great vessels.
Coarctation of the aorta.
Retroesophageal aortic arch.
Which malformations are considered under the class “truncus defects?”
How can you quickly diagnose a coarctation of the aorta in a newborn, if suspected