heart development

Question 1

general overview of heart development

Answer 1

• cardiac crescent (contains primary heart field)
• heart tube
• pre-septated looped heart
• four chambered heart

Question 2

progenitor heart cells migrate through primitive streak into the:

Answer 2

splanchnic layer of lateral plate mesoderm

Question 3

1st sign of heart formation is a solid, ____ shaped cluster of cells called the ______

Answer 3

horseshoe; primary heart field

Question 4

once cells establish the primary heart field, they are induced by underlying ____ to form ____ and blood islands and vessels by the process of _____

Answer 4

endoderm; cardiac myoblasts; vasculogenesis

Question 5

blood vessels arising from blood islands; mesoderm cells > hemangioblasts > tube formation; formation of blood vessels de novo (embryonic process)

Answer 5

vasculogenesis

Question 6

blood vessels sprouting from existing vessels

Answer 6

angiogenesis

Question 7

islands will unite and form a horseshoe-shaped _____ lined tube surrounded by ____ within the ____ region; these are called _____ tubes

Answer 7

endothelial; myoblasts; cardiogenic; endocardial

Question 8

other blood islands appear bilaterally which will form the pair of longitudinal _____

Answer 8

dorsal aortae

Question 9

the lateral sides of the horseshoe shaped endothelial tube fold in ____ and ____, approaching eachother at the midline to fuse, forming a single ____

Answer 9

ventrally; medially; primordial heart tube

Question 10

_____ creates primordial heart tube

Answer 10

lateral body folding

Question 11

due to rapid neural tube growth, embryo also undergoes _____ folding or ____ folding

Answer 11

cranial to caudal folding; sagittal

Question 12

cranial-caudal folding ____ the developing heart and _____

Answer 12

repositions; pericardial cavities

Question 13

initially, the heart tube is attached to the dorsal side of the pericardial cavity via ____

Answer 13

dorsal mesocardium

Question 14

the middle section of the dorsal mesocardium will disappear and create the _____

Answer 14

transverse pericardial sinus

Question 15

dilations of the heart tube from caudal to cranial

Answer 15

• sinus venosus
• primordial atrium
• primordial ventricle
• bulbus cordis (conus cordis + truncus arteriosus)

Question 16

where rhythmic contractions of the heart tube become organized

Answer 16

sinoatrial canal

Question 17

the myocardial tissue in the sinoatrial canal gives rise to the ____ and ____

Answer 17

sinoatrial and atrioventricular nodes

Question 18

usually days ____ correlate with the first heart beat

Answer 18

22/23

Question 19

sinus venosus becomes:

Answer 19

coronary sinus and sinus venarum

Question 20

primordial atrium becomes:

Answer 20

right and left auricles + portions of the atria

Question 21

primordial ventricle becomes:

Answer 21

left ventricle

Question 22

conus cordis becomes:

Answer 22

outflow tract of ventricles; caudal portion of bulbus cordis forms right ventricle

Question 23

truncus arteriosus becomes:

Answer 23

pulmonary trunk and aorta

Question 24

____ will connect to dorsal aortae

Answer 24

pharyngeal arch aa.

Question 25

primitive ventricles move ___ and to the ____ while atrial region moves ____ and to the ____

Answer 25

ventrally; right; dorsally; left

Question 26

sinus venosus receives venous blood from 3 paired veins:

Answer 26

1. vitelline vv.
2. umbilical vv.
3. common cardinal vv.

Question 27

left sinus horn becomes:

Answer 27

• oblique veins of the L atrium

- coronary sinus

Question 28

right sinus horn entrance into the right atrium is called the ____, flanked by ____

Answer 28

sinuatrial orifice; right and left venousvalves

Question 29

when right sinus horn is incorporated into the wall of the right atrium it is called ____

Answer 29

sinus venarum

Question 30

inferior portion of right valve becomes:

Answer 30

• valve of IVC

- valve of coronary sinus

Question 31

near end of week 4, _____ form on each side of chamber plus one on dorsal and ventral walls of AV canal

Answer 31

four atrioventricular (AV) endocardial cushions

Question 32

fusion of these cushions results in complete division of:

Answer 32

AV canal into and left and right

Question 33

around end of week 4, crest of tissue grows from roof of common atrium called ____

Answer 33

septum primum

Question 34

opening below the septum primum and endocardial cushions is the ____

Answer 34

ostium primum

Question 35

cell death produces perforations in ____ which coalesce to form ____

Answer 35

septum primum; ostium secundum

Question 36

As holes in the septum primum coalesce to form the ostium secundum, a thicker _____ develops from the roof of the _____, slightly to the ____ of the septum primum

Answer 36

septum secundum; primordial atrium; right

Question 37

septum secundum grows inferiorly and develops an opening:

Answer 37

foramen ovale

Question 38

After birth, the pressure in the left atrium increases as the blood returns from the lungs.
_____ is pressed against the ______ and adheres to it, permanently closing the ____ and forming the _____

Answer 38

septum primum; septum secundum; foramen ovale; fossa ovalis

Question 39

End of week 4, primitive ventricles begin to expand;

Medial walls will merge together to form the _____ with ____ located above it

Answer 39

muscular interventricular septum; interventricular foramen

Question 40

outgrowth of the _____ closes the interventricular foramen; complete closure forms the ____

Answer 40

inferior endocardial cushion; membranous part of the interventricular septum

Question 41

during week 5, neural crest cells migrate into ____ and ____, forming ____ and ____

Answer 41

migrate into truncus arteriosus and bulbus cordis; form truncal ridges and bulbar ridges

Question 42

Ridges undergo a ____ spiraling which results in the formation of a ______when the ridges fuse

Answer 42

180 degree

spiral aorticopulmonary septum

Question 43

ridges also grow ____ to contribute to ____

Answer 43

inferiorly; membranous interventricular septum