Cardiac Development

Question 1

cardiac progenitor cells

Answer 1

migrate in and form the primary and secondary heart fields

Question 2

primary heart field

Answer 2

will give rise to atria and ventricles

Question 3

secondary heart field

Answer 3

will form part of right ventricle, bulbis cordis, and truncus arteriosus

Question 4

endocardial tube

Answer 4

will form from fusion of two dorsal aortas, held in place at midline by dorsal mesocardium

Question 5

outflow tract

Answer 5

truncus arteriosus

Question 6

inflow tract

Answer 6

sinus venosus

Question 7

truncus arteriosus gives rise to _

Answer 7

aorta and pulmonary trunk

Question 8

bulbis cordis gives rise to _

Answer 8

smooth part of RV and LV

Question 9

conus arteriosus

Answer 9

smooth part of right ventricle

Question 10

aortic vestibule

Answer 10

smooth part of left ventricle

Question 11

primitive ventricle

Answer 11

thick part (trabeculated) of left and right ventricle

Question 12

primitive atrium

Answer 12

gives rise to thick part of left and right atrium

Question 13

sinus venosus gives rise to _

Answer 13

sinus venarium, coronary sinus, and oblique vein of left atrium

Question 14

sinus venarium

Answer 14

smooth part of right atrium

Question 15

crista terminalis

Answer 15

junction of thick and smooth right atrium

Question 16

pulmonary vein

Answer 16

smooth part of left atrium

Question 17

shifting of sinus venosus

Answer 17

as heart twists, inflow tract gets rearranged –> shifts sinus venosus from midline to right –> R and L umbilical vein and L vitelline vein disappear –> right vitelline vein remains to form SVC and IVC

Question 18

left horn (part of sinus venosus that disappeared) will form _

Answer 18

coronary sinus and oblique vein of left atrium

Question 19

cells that participate in formation of endocardial cushion are derived from _

Answer 19

cardiac neural crest cells

Question 20

atrial septum forms from the _

Answer 20

septum primum

Question 21

development of atrial septum

Answer 21

septum primum stretches downward towards endocardial cushions –> fills in the foramen primum –> cells in upper part of septum primum will apoptose to form new opening, foramen secundum –> right sinus horn will now form its part of the atrium, the septum secundum –> opening in this secundum is the foramen ovale

Question 22

septum primum

Answer 22

has a valve to close the foramen ovale at birth

Question 23

foramen ovale

Answer 23

shunts blood from right atrium to left atrium in utero

Question 24

dorsal mesocardium protrusion

Answer 24

forms pulmonary veins in the left atrium (1 opening to 4) and also participates in endocardial cushion formation

Question 25

septation in AV canal

Answer 25

due to outgrowth of four cushions

Question 26

swellings in truncus arteriosus allow it to form _

Answer 26

aortic and pulmonary tracts

Question 27

ventricular septation forms as a result of _

Answer 27

ventricles growing, will form a muscular ridge

Question 28

conus septum

Answer 28

forms the septum between two ventricles

Question 29

completion of conus septum

Answer 29

will not be complete until membranous portion connects muscular to endocardial cushion

Question 30

AV valve formation

Answer 30

endocardial cushion cells aggregate --> blood flow erodes --> this tissue will evolve into fibrous CT of valve leaves

Question 31

SL valve formation

Answer 31

neural crest cells accumulate in truncus arteriosus --> eventually erode and form SL valves

Question 32

patent ductus arteriosus

Answer 32

failure of ductus arteriosus to close, which leaves connection between aorta and pulmonary artery

Question 33

results of patent ductus arteriosus

Answer 33

aorta will pump too much blood into the lungs, causing heart to be overworked

Question 34

ligamentum arteriosum

Answer 34

attaches aorta to pulmonary artery; remnant of the ductus arteriosus in utero

Question 35

ostium secundum defect

Answer 35

an ASD that leaves hole in center of septum dividing two atria

Question 36

symptoms of ostium secundum defect

Answer 36

shortness of breath, respiratory infections, irregular heart beat, fatigue (heart is being overworked)

Question 37

tetralogy of Fallot

Answer 37

VSD which results in unequal division of conus septum --> oxygen poor blood in RV mixes with oxygen rich blood in LV

Question 38

result of tetrology of fallot

Answer 38

overriding aorta, right ventricular hypertrophy, right ventricular outflow tract obstruction

Question 39

aortic arch 3

Answer 39

becomes the common carotid

Question 40

left aortic arch 4

Answer 40

will be left aortic arch

Question 41

right aortic arch 4

Answer 41

will be right subclavian artery

Question 42

left aortic arch 6

Answer 42

will be left pulmonary artery and ductus arteriosus

Question 43

right aortic arch 6

Answer 43

will be right pulmonary artery

Question 44

vitelline arteries will form _

Answer 44

celiac and mesenteric arteries

Question 45

umbilical arteries will form _

Answer 45

iliac arteries and inferior mesenteric arteries

Question 46

vitelline veins become

Answer 46

hepatic vein s

Question 47

coarctation of aorta

Answer 47

blood reaches lower part of body via collateral circulation (left subclavian, intercostal, and internal thoracic arteries)

Question 48

symptoms of coarctation of aorta

Answer 48

increased BP in upper extremities, no pulse in femoral artery, high risk of cerebral hemorrhage

Question 49

abnormal origin of right subclavian artery

Answer 49

right aortic arch 4 regresses --> right subclavian artery must now cross midline to supply right arm

Question 50

closures at birth

Answer 50

ductus arteriosus, foramen ovale, umbilical arteries, umbilical veins, ductus venosus