02a: Heart Development

Question 1

Primordial heart cells originate in (X), migrate through (Y) between (ectoderm/mesoderm/endoderm) layers.

Answer 1

X = epiderm
Y = primitive streak

Between endoderm and ectoderm layers

Question 2

Primordial heart cells migrate (rostrally/caudally) and eventually position themselves (rostral/caudal) to (X) in which post-gastrulation layer?

Answer 2

Rostrally;
rostral to
X = oropharyngeal membrane
In splanchnic (lateral) mesoderm

Question 3

Primary heart field will form:

Answer 3

1. Atria
2. LV
3. Part of RV

Question 4

Secondary heart field will form:

Answer 4

1. Part of RV

2. Outflow tracks (conus cordis, truncus arteriosus)

Question 5

Fusion of (X) tubes to form heart tube occurs after (Y) event.

Answer 5

X = endocardial
Y = lateral body folding

Question 6

Heart tube has inner (X) and outer (Y) layer.

Answer 6

X = endothelial lining
Y = myocardial

Question 7

Cardiac jelly found between which layers in heart tube?

Answer 7

Endothelial (inner) and myocardial (outer)

Question 8

(X) forms the epicardium of the heart.

Answer 8

X = mesothelium and underlying CT

Question 9

Any organ suspended in intraembryonic cavity will be lined by:

Answer 9

Mesothelium

Question 10

Head folding translocates developing endocardial tubes from (X) to (Y).

Answer 10

X = region cranial to neural plate
Y = thoracic region

Question 11

Epicardium, aka (X), is responsible for forming (Y).

Answer 11

X = serous pericardium
Y = coronary arteries

Question 12

Primordial heart tube receives venous drainage at (caudal/cranial) pole and pumps blood out at (caudal/cranial) pole.

Answer 12

Caudal; cranial

Question 13

Primordial heart tube is attached to (X) side of pericardial cavity by (Y).

Answer 13

X = dorsal
Y = dorsal mesocardium

Question 14

Fate of dorsal mesocardium.

Answer 14

Central portion breaks down and gives rise to transverse pericardial cavity

Question 15

Cranial end of primary heart tube is attached to (X). Caudal end is attached to (Y).

Answer 15

X = pharyngeal arches
Y = septum transversum

Question 16

As heart tube continues to elongate, it forms (X) number of dilations. List them, from caudal to cranial.

Answer 16

X = 5

1. Sinus venosus
2. Primitive atrium
3. Primitive ventricle
4. Bulbus cordis
5. Truncus arteriosus

Question 17

Primitive atrium will eventually contribute to:

Answer 17

1. All LA

2. Trabeculated part of RA

Question 18

Primitive ventricle will eventually contribute to:

Answer 18

Trabeculated part of LV

Question 19

Primitive proximal bulbus cordis will eventually contribute to:

Answer 19

Trabeculated part of RV

Question 20

Primitive distal bulbus cords, aka (X), will eventually contribute to:

Answer 20

X = conus cordis

Smooth parts of RV and LV

Question 21

Primitive truncus arteriosus will eventually contribute to:

Answer 21

Proximal ascending aorta and pulmonary trunk

Question 22

T/F: Heart tube is asymmetrical throughout development.

Answer 22

False - bilaterally symmetrical in early development

Question 23

T/F: Cells from secondary heart field will eventually become incorporated into primary heart field.

Answer 23

True

Question 24

(X) area(s) of primitive heart will undergo rapid growth and the heart will undergo (Y) looping.

Answer 24

X = proximal bulbus cordis and primitive ventricle
Y = dextral

Question 25

During cardiac looping, proximal bulbus cords is displaced in which directions?

Answer 25

Caudally, ventrally, and to the right

Question 26

During cardiac looping, primitive ventricle is displaced in which directions?

Answer 26

To the left

Question 27

During cardiac looping, primitive atrium is displaced in which directions?

Answer 27

Dorsally and cranially

Question 28

GENERAL direction of cardiac looping in cephalic portion of heart tube.

Answer 28

Caudally, ventrally, to the right

Question 29

GENERAL direction of cardiac looping in caudal portion of heart tube.

Answer 29

Cranially, dorsally, to the left

Question 30

Primitive inflow of blood to heart initially supplied by (X) pairs of major veins that enter (Y)

Answer 30

``` X = 3 Y = sinus venosus ```

Question 31

List the primitive inflow vessels associated with heart tube. Star those, if any, carrying oxygenated blood.

Answer 31

1. Vitelline veins 2. Umbilical veins* 3. Common cardinal veins

Question 32

Vitelline veins carry (oxygenated/deoxygenated) blood from (X).

Answer 32

Deoxygenated; | X = yolk sac/intestinal area

Question 33

Umbilical veins carry (oxygenated/deoxygenated) blood from (X).

Answer 33

Oxygenated; | X = placenta

Question 34

Common cardinal veins carry (oxygenated/deoxygenated) blood from (X).

Answer 34

Deoxygenated; | X = entire embryo (into heart)

Question 35

Upon remodeling of the heart's inflow end, sometime in weeks 4-8, what changes occur?

Answer 35

All systemic blood flows into future right atrium

Question 36

Fate of vitelline veins.

Answer 36

Form: 1. Portion of IVC 2. Portal vein 3. Splenic vein 4. Superior and inferior mesenteric veins

Question 37

Fate of umbilical veins.

Answer 37

Right: regresses Left: continues to carry oxygenated blood from placenta to embryo

Question 38

Fate of cardinal veins.

Answer 38

Form: 1. Brachiocephalic vein 2. SVC and part of IVC

Question 39

List adult remnants of left sinus horn, which is part of (X).

Answer 39

X = sinus venosus 1. Oblique vein of LA 2. Coronary sinus

Question 40

List adult remnants of right sinus horn, which is part of (X).

Answer 40

X = sinus venosus Incorporated into RA as: 1. Sinus venarum (smooth-walled portion) 2. IVC and coronary sinus valves 3. Crista terminalis

Question 41

In fetal circulation, (X) supplies fetus with (Y)% oxygenated blood from (Z).

Answer 41

``` X = umbilical vein Y = 80 Z = placenta ```

Question 42

In fetal circulation, most blood to liver will:

Answer 42

flow through ductus venosum, directly to IVC

Question 43

In fetal circulation, most blood entering RA will:

Answer 43

pass directly to LA via oval foramen

Question 44

In fetal circulation, blood entering LA, and then exiting to (X), is (well/partially/poorly)-oxygenated.

Answer 44

X = head and neck (via ascending aorta) | Well-oxygenated

Question 45

In fetal circulation: Since (X) resistance is high, some blood entering RA and (Y) will get shunted by (Z) to the (ascending/descending) aorta.

Answer 45

``` X = pulmonary Y = pulmonary trunk Z = ductus arteriosus ``` Descending aorta

Question 46

In fetal circulation, blood flows bak to the placenta via:

Answer 46

Umbilical arteries

Question 47

After birth, which event causes constricted pulmonary vessels to open?

Answer 47

Alveoli fill with air

Question 48

Adult remnant of umbilical vein.

Answer 48

Ligamentum teres

Question 49

Adult remnant of ductus venosus.

Answer 49

Ligamentum venosum

Question 50

Adult remnant of ductus arteriosus.

Answer 50

Ligamentum arteriosus

Question 51

Adult remnant of umbilical arteries.

Answer 51

Proximal: superior vesical artery Distal: Medial umbilical ligaments

Question 52

Lung development begins with (ventral/dorsal) foregut forming (X).

Answer 52

Ventral; | X = respiratory diverticulum

Question 53

Which part of respiratory system, if any, is derived from endoderm?

Answer 53

Only the epithelium that lines larynx, trachea, bronchi, etc.

Question 54

(Most/all) of respiratory system derived from:

Answer 54

Most; splanchnic mesoderm | except epithelial lining, derived from endoderm

Question 55

(X) structure develops and divides trachea/lung buds from (Y).

Answer 55

``` X = tracheoesophageal septum Y = esophagus ```

Question 56

In development of lungs, (X) covering outside of lung will eventually develop into visceral pleura and (Y) covering body wall will develop into parietal pleura.

Answer 56

X = Y = mesoderm