Embryo-Development Of The Heart

Front 1

The intricate structure of the heart develops during the first ______ weeks of life.

Back 1

eight

Front 2

the heart begins to beat on the ___ day

Back 2

22nd

Front 3

Starts from ______ rostral to the oral plate, adjacent to the septum transversum.

Back 3

mesoderm

Front 4

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.

Back 4

18

Front 5

Induction of heart tubes happens when?

Back 5

week 2-3

Front 6

Heart begins beating
when?

Back 6

week 3-4

Front 7

Heart partitioning happens when?

Back 7

week 4-6

Front 8

Great Arteries transform
when?

Back 8

week 6-7

Front 9

Completion of valves
happens when?

Back 9

week 7-8

Front 10

___ proteins activate mesoderm to form certain gene products that enhance musculoskeletal development.

Back 10

BMP

Front 11

Expression of ____ genes result in heart induction.

Back 11

NKX-2.5

Front 12

Paired Heart Tubes Develop as a result of overlap between the positive ___ genes and inhibitory ___ genes

Back 12

BMP
WNT

Front 13

Origin of the heart begin _____ days

Back 13

18-22

Front 14

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.

Back 14

NKX

Front 15

earliest expression of heart development are the _____

Back 15

blood islands

Front 16

blood islands are associated with the ________.

Back 16

septum transversum

Front 17

the blood islands develop into ______(which is a simple squamous epithelium, similar to endothelium).

Back 17

endocardium

Front 18

The heart begins as TWO ____ , a left and a right one.

Back 18

tubes

Front 19

Formation of the heart tube begins as the cardiogenic ________ fuse into a presumptive heart

Back 19

blood spaces

Front 20

Mesoderm in the developing aortic arches develop into _________, starting with A.A. #1,

Back 20

branchial arches

Front 21

at the venous end the mesoderm begins to form a series of veins from a relatively poorly defined mass referred to as the ___________

Back 21

angioblastic plexus

Front 22

Cardiogenic mesoderm differentiates into _______ and _______ on the outside of the heart, while the endocardium continues to line the inside of the heart.

Back 22

myocardium
cardiac jelly

Front 23

Neural crest develops into _______ and ________

Back 23

aortic root
parasympathetic ganglia

Front 24

The ___________ , and its _________ lining, forms from mesoderm in the area adjacent to the developing heart, as discussed in core embryo.

Back 24

pericardial cavity mesothelium

Front 25

Development of the heart occurs in days _____

Back 25

22-26

Front 26

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 _________

Back 26

Inversion of the heart tube

Front 27

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.

Back 27

21

Front 28

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).

Back 28

clockwise

Front 29

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 _________.

Back 29

dorsal mesocardium
dorsal mesocardium
dorsal mesocardium

Front 30

Systemic arteries shift to the ______ with the development of the aorta

Back 30

left

Front 31

Systemic veins shift to the ____ as the opening for the sinus venosus moves to the right side of the atrium

Back 31

right

Front 32

Partitioning of the Heart occurs days ____.

Back 32

28-35

Front 33

The _______ separates the atria from the ventricles, provides a central point for the left right separation of the heart chambers

Back 33

Endocardial Cushion

Front 34

The Endocardial Cushion contains many cells of ______ origin.

Back 34

neural crest

Front 35

The superior & inferior E.C. will fuse on day 42 to become the single _______.

Back 35

septum intermedium

Front 36

The fusion of the E.C leaves behind two openings from atria to ventricles, the ________.

Back 36

atrioventricular canals

Front 37

The _________ is the original communication between L & R atria. It closes completely

Back 37

Foramen primum

Front 38

The ______ closes the foramen primum. Because there must be blood flow from right to left atrium, another hole arises (next).

Back 38

Septum primum

Front 39

The __________ is the secondary interatrial passage (essential for allowing blood to get into left atrium, and therefore left ventricle).

Back 39

Foramen secundum

Front 40

The _____ forms valve that permits blood to flow only from right atrium to left atrium, not the reverse.

Back 40

Septum secundum

Front 41

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)

Back 41

Foramen ovale

Front 42

The ______________ arises from interventricular septum.

Back 42

Muscular interventricular septum

Front 43

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).

Back 43

interventricular foramen

Front 44

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 ____________.

Back 44

Membranous interventricular septum

Front 45

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.

Back 45

Programmed cell death

Front 46

Spiral septum derives primarily from ________

Back 46

neural crest

Front 47

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.

Back 47

pulmonary
aortic

Front 48

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.

Back 48

truncus
bulbus

Front 49

The spiral septum merges inferiorly with the developing _______, ensuring the vessels are in continuity with the ventricles.

Back 49

muscular interventricular septum

Front 50

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

Back 50

back
front

Front 51

Note that the spiral septum also fuses simultaneously with the _______ in formation of the membraneous interventricular septum.

Back 51

endocardial cushon (septum intermedium)

Front 52

Human therapy is theoretically possible, but will require ______

Back 52

stem cells

Front 53

When does the heart begin its formation?

Back 53

-

Front 54

When does it begin to beat?

Back 54

-

Front 55

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.

Back 55

-

Front 56

Explain how the atria and ventricles separate from one another

Back 56

-

Front 57

. Explain how the right and left atria, and R. and L. ventricles, separate.

Back 57

-

Front 58

What is the function of the foramen ovale the final (fetal) pattern of blood flow?

Back 58

-

Front 59

Explain how the bulbar septum fits into this pattern.

Back 59

-

Front 60

Why is the bulbar septum spiral in shape?

Back 60

-

Front 61

Explain how the heart can continue to function while changing from the embryonic to fetal patterns of blood flow.

Back 61

-

Front 62

Explain the development of the smooth-walled portion of the atria as well as the origin of the auricles.

Back 62

-

Front 63

The ________ receives blood from truncus arteriosus, and distributes it to all of the aortic arches.

Back 63

Aortic sac

Front 64

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.

Back 64

Aortic arches

Front 65

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.

Back 65

dorsal aortae

Front 66

The _____ branch off of the dorsal aorta which segmentally supply parts of the periphery.

Back 66

Intersegmental arteries

Front 67

the 7th intersegmental becomes the ______ and parts of the _______.

Back 67

subclavian
axillary artery

Front 68

The _________ supply the yolk sac. Its main branches become celiac, superior mesenteric and inferior mesenteric arteries.

Back 68

Vitelline arteries

Front 69

The _______ arise from the internal iliac arteries. All fetal blood going to the placenta arise from the two umbilical arteries.

Back 69

Umbilical arteries

Front 70

Arch #1, bilaterally--

Back 70

Maxillary artery

Front 71

Arch #2, bilaterally--

Back 71

lost

Front 72

Arch #3 bilaterally, along with the more superior portions of the anterior dorsal aortae of the head, become the __________ .

Back 72

internal carotid arteries

Front 73

Carotid duct (short part of dorsal aorta)

Back 73

disappears

Front 74

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.)

Back 74

Right subclavian artery

Front 75

A portion of the RIGHT aortic sac becomes the _________.

Back 75

Right brachiocephalic artery

Front 76

A portion of the RIGHT dorsal aorta of the head, which is distal to the 7th intersegmental A

Back 76

lost without any trace

Front 77

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.)

Back 77

Arch of the aorta

Front 78

LEFT seventh intersegmental artery; this is the only vessel contributing to the ___________ and parts of the L. Axillary A

Back 78

Left Subclavian artery

Front 79

Arch #6 (bilaterally) contributes to ______ and (on the left side only) _______.

Back 79

Pulmonary arteries
ductus arteriosus

Front 80

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.

Back 80

ductus arteriorus

Front 81

On the right side only, the part of the 6th arch which connects to the R. dorsal aorta of the head _________.

Back 81

dissappears

Front 82

___________ initially supplies the yolk sac.

Back 82

Vitelline artery

Front 83

Vitelline artery branches supply the developing gut and eventually become the ________,_______and _______ arteries.

Back 83

Celiac, superior and inferior mesenteric

Front 84

_________ supply blood to the placenta via the umbilicus

Back 84

Umbilical arteries

Front 85

Eventually, around the umbilical arteries, develop the ________ and __________.

Back 85

internal and external iliac arteries

Front 86

All blood returning from the heart passes first through a ____ or _____ , which joins a common sinus venosus before emptying into the atrium.

Back 86

left or right sinal horn

Front 87

A series of _________ develop early on, which quickly develops connections to all of the major veins.

Back 87

venous antioblastic plexuses

Front 88

______ drain the yolk sac, where the first blood cells begin formation around the fourth week.

Back 88

Vitelline veins

Front 89

drain the placenta, supplying “oxygenated” blood to the fetus.

Back 89

Umbilical veins

Front 90

________ are the veins of the embryo proper, draining all parts of the embryo to the sinus venosus

Back 90

Cardinal system of veins

Front 91

__________ drain the head and what will eventually become parts of the chest.

Back 91

Anterior cardinal veins

Front 92

________ 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

Back 92

Posterior cardinal veins

Front 93

The anterior and posterior cardinal veins join together to become _______, before they empty into the sinal horn.

Back 93

common cardinal veins

Front 94

Shift of systemic venous circulation to the right involves a reduction of the left sinal horn to form the ________

Back 94

coronary sinus

Front 95

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.

Back 95

sinus venosus

Front 96

. 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.

Back 96

sinus venerium

Front 97

Superior vena cava from ______ and ________

Back 97

R. common
anterior cardinal

Front 98

L. brachiocephalic v. anastamoses through developing mediastinum to R. brachiocephalic to join ______

Back 98

S.V.C.

Front 99

Note that _______ gives rise to the Azygos system.

Back 99

R. posterior cardinal V

Front 100

Also note the remnants of the _______ will give rise to a ligamentous remnant called the ‘ligament of the left superior vena cava.’

Back 100

L. anterior cardinal V.

Front 101

________ pierces diaphragm to form terminal segment of inferior vena cava.

Back 101

R. vitelline vein

Front 102

IVS then anastomoses to _____.

Back 102

cardinal veins

Front 103

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.

Back 103

ductus venosus

Front 104

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.

Back 104

umbilical vein

Front 105

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.

Back 105

foramen ovale

foramen secundum

Front 106

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 _______.

Back 106

ductus arteriosus

Front 107

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.

Back 107

-

Front 108

What is the pattern of circulation in the normal fetus

Back 108

-

Front 109

What changes take place at birth?

Back 109

-

Front 110

How do these changes take place?

Back 110

-

Front 111

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.

Back 111

-

Front 112

Oxygenated blood returns to the embryo via the _______.

Back 112

umbilical vein

Front 113

Oxygenated blood returned to the embryo via the umbilical vein can mix with unoxygenated blood from the ____________.

Back 113

hepatic portal system

Front 114

Moderately oxygenated blood from IVC is shunted to left atrium via the _______

Back 114

foramen ovale

Front 115

unoxygenated blood in SVC is directed to ________

Back 115

right atrium

Front 116

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).

Back 116

ductus arteriosus

Front 117

When the umbilical cord is clamped, blood ceases to flow through the umbilical V.; the ________ will then close down.

Back 117

ductus venosus

Front 118

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.

Back 118

right atrial pressure

Front 119

The concomitant increase in pulmonary blood flow causes increased blood flow to lungs, and therefore to ________

Back 119

L. atrium

Front 120

With the lungs functioning, the increase in blood oxygen stimulates the ________ to close, establishing the adult circulatory pattern.

Back 120

ductus arteriosus

Front 121

Dextrocardia

Back 121

reverse rotation

Front 122

Ectopia cordis

Back 122

heart external to body

Front 123

Atrial septal defect

Back 123

hole” between the two atria

Front 124

(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.

Back 124

Patent foramen ovale

Front 125

(patent foramen primum; failure of septum primum to fuse with endocardial cushion)

Back 125

Endocardial cushion defect with primum type defect.

Front 126

Common atrium

Back 126

no septa whatsoeve

Front 127

incomplete absorption into R. atrium. Associated with defective pulmonary veins.

Back 127

Sinus venosus defect

Front 128

(most common). Hole in membraneous interventricular septum.

Back 128

Membranous septal defect

Front 129

‘swiss cheese’ defect, many small holes in trabecular carneae.

Back 129

Muscular septal defect

Front 130

Very rare; (3 chambered heart).

Back 130

absence of septum

Front 131

Aorta arises from R. Ventricle, Pulmonary trunk from left.

Back 131

Transposition of great vessels

Front 132

Aorta and pulmonary trunk do not separate, complete mixing of blood.

Back 132

Persistent truncus arteriosus.

Front 133

Unequal division of great vessels.

Back 133

Aortic or pulmonary stenosis.

Front 134

Tetralogy of Fallot: Aortic or pulmonary stenosis.

Back 134

Narrowing of pulmonary valve; undrelying cause of rest of problems.

Front 135

Tetralogy of Fallot: Ventricular septal defect

Back 135

Needed to shunt blood to aorta

Front 136

Tetralogy of Fallot: Over riding aorta.

Back 136

Sits over interventricular septum

Front 137

Tetralogy of Fallot: Hypertrophy of right ventricle.

Back 137

Response to increased workload.

Front 138

Aortic coarctation

Back 138

narrowing of aorta

Front 139

coarctation proximal to ductus arteriosis.

Back 139

Preductal

Front 140

Coarctation distal to ductus arteriosis

Back 140

Postductal

Front 141

(connection or R. dorsal aorta of head to dorsal aorta of body does not involute: aortic arch surrounds esophagus)

Back 141

Double aortic arch.

Front 142

(Aortic arch from R. side, goes between esophagus and vertebra).

Back 142

Retroesophageal aortic arch.

Front 143

(ductus arteriosus patent into childhood or even adulthood).

Back 143

Patent ductus arteriosis.

Front 144

(second IVC following the L. Common Cardinal into coronary sinus)

Back 144

Double superior vena cava.

Front 145

(IVC empties into coronary sinus on left, not found on right)

Back 145

Left SVC.

Front 146

(IVC blood joins azygos blood flow into SVC).

Back 146

Absence of hepatic segment of IVC.

Front 147

(two IVC’s surrounding Abdominal aorta).

Back 147

Double IVC.

Front 148

(one pulmonary V. empties into SVC).

Back 148

Partially anomalous venous return.

Front 149

Describe which developmental process didn’t work properly in the following malformations:
ASD
VSD
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.

Back 149

-

Front 150

Which malformations are considered under the class “truncus defects?”

Back 150

-

Front 151

How can you quickly diagnose a coarctation of the aorta in a newborn, if suspected

Back 151

-