3-G Heart Development

Question 1

What happens during the migration and carivation part of the development?

Answer 1

cardiogenic mass cavitates, forming two parallel tubes that fuse into a single heart tube, blood flowing through sinus venous, primitive ventricle, primitieve atrium, conus cordus and trncus arteriosus

Question 2

What happens during the Bending and Folding stage of heart development?

Answer 2

the heart grows within the constricting pericardial sac, which causes it to fold in places that have slower growth in diameter: the atrium moves caudally to cranially and slightly to the left; the ventricle moves anteriorly, caudally and to the right

Question 3

Does the pattern of blood in the heart change after folding?

Answer 3

No, the pattern of flow still flows through the same cardiac tube.

Question 4

What tissue growth contributes to the septation of the AV canal?

Answer 4

growth of the endocardial cushions

Question 5

The septation fo the atrioventricular canal creates what two cavities?

Answer 5

atria and ventricles, creating an H shaped hole between the two cavities because the endcardial cushions are growing

Question 6

The separation of the right and left atrium leads to the creation of which two embryonic septum?

Answer 6

septum primum and septum secundum

Question 7

Describe the direction the septum primum grows as it forms.

Answer 7

septum primum grows down from the cranial end of the common atrium

Question 8

Describe the two holes in the septum primum

Answer 8

the ostium primum closes as the osteium secunda is formed (via cell death)

Question 9

Describe the position and substance of the septum secundum

Answer 9

septum segundum is positioned to the right side (growing downward) of the septum primum and is more rigid and thick thatn the septum primum

Question 10

Name the hole in the septum secundum

Answer 10

foramen ovale

Question 11

What causes blood to flow from the right to left atria once the septum are formed.

Answer 11

high pressure in the right and low pressure in the left atrium cause the septum primum to pushed aside when blood travels through

Question 12

Describe the four components of the interventricular septum

Answer 12

the right and left trunconal ridges, the muscular interventricular septum and a portions of the inferior endocardial cushion

Question 13

What can be seen in the adult of the spot where all the parts of the ventricular septum joined?

Answer 13

the membranous part of the interventricular septum

Question 14

Common outflow tracts are subdivided into which vessels

Answer 14

the pulmonary trunk and the aorta

Question 15

Common out flow tracts include what former parts of the embryonic heart?

Answer 15

the truncus arteriosus and the conus cordis

Question 16

What forms the aorticopulmonary septa?

Answer 16

Truncoconal ridges

Question 17

Describe the septum that forms to divide the pulmonary trunk and aorta

Answer 17

spiral septum, tracts of outflow cross as they exit the heart

Question 18

In the adult, the aorta located in what position in relation to the pulmonary trunk?

Answer 18

anterior

Question 19

What does the umbilical vein connect?

Answer 19

placenta to liver, delivering oxygenated blood

Question 20

Where is the ductus venosus located?

Answer 20

located in the liver, it acts as a bypass of the liver directly to the inferior vena cava

Question 21

What is the function of the foramen ovale?

Answer 21

shunts blood between the right and left atrium

Question 22

What embryonic circulatory elements does the umbilical artery connect?

Answer 22

carries unoxygenated blood from the internal iliac arteries to the placenta

Question 23

What structures does the ductus arteriosus connect?

Answer 23

the pulmonary trunk and the aorta in order to bypass the fetal lungs

Question 24

Because oxygenated and non oxygenated blood mixes, what is a characteristic of oxygen carrying capability of the embryo that helps to compensate?

Answer 24

fetal hemoglobin can cary 20-30 more oxygen than maternal blood due to increased oxygen affinity

Question 25

Define major circulation

Answer 25

circuit of blood coming from the placenta and going to the body

Question 26

Define minor circulation

Answer 26

the pulmonary circuit, until the infant takes first breathes the collapsed capillary beds offer a lot of resistence in this circuit

Question 27

The common outflow tract is subdivided into the pulmonary trunk and the aorta by the right and left _______ ________

Answer 27

truncoconal ridges, these ridges form in a spiral to form the aorticopulmonary /spiral septum which reaches down to meed the muscular portion of the intervetnricular septum

Question 28

The inter ventricular septum is formed from four elements: ?

Answer 28

right and left truncoconal ridges, muscular inter ventricular septum and a portion of the inferior endocardial cushion

Question 29

In fetal circulation, which has greater O2 content, the superior or inferior vena cava?

Answer 29

Inferior, it is carrying oxygenated blood from the umbilical veins, while the superior is carrying blood returning only from the systemic circulation

Question 30

What is probe patency (concerning the heart)

Answer 30

another name for the condition when the foramen ovale does not close completely (rarely symptomatic because higher pressure in the left atrium prevents blood flow)

Question 31

Upon birth, which direction does blood flow through the ductus arteriosum?

Answer 31

from the aorta to the pulmonary trunk

Question 32

Non-cyanotic malformations result in ____ to ______ shunt of blood.

Answer 32

left to right; they include ventricular septal defects and atrial septal defects

Question 33

Cyanotic malformations result in a _____ to _____ shunt

Answer 33

right to left; these include patent ductus arteriosus, transposition of the great vessels, persistent truncus arteriosus, tetralogy of fallot (ventricular septal defect, overriding aorta, pulmonary stenosis and right ventricular hypertrophy