Development Of The Heart

Question 1

The heart develops from

Answer 1

paired endothelial strands - angioblastic cords (Solid cord of cells),
in the splanchnic mesoderm in relation to pericardial coelom (part of the intraembryonic
coelom),

Question 2

Heart begin to develop during —week of development

Answer 2

3rd

Question 3

The angioblastic cords canalize to form————-, which fuse to form——-

Answer 3

endocardial heart tubes

tubular heart.

Question 4

To begin with fused endocardial heart tube is ventral to the———- and cranial to the———-

Answer 4

pericardial cavity

oropharyngeal membrane.

Question 5

with head fold formation, pericardial cavity and tubular heart come to lie——-, in the future neck region

Answer 5

ventral to the foregut

Question 6

pericardial cavity is ventral to the heart tube.

That why the heart is related ventral and anterior to esophagus

Answer 6

K

Question 7

The heart tube invaginates into the———from its——

Answer 7

pericardial cavity

dorsal side.

Question 8

With the formation of lateral folds, left and right endocardial heart tubes fuse to form

Answer 8

median fused tubular heart.

Question 9

Invagination of the fused endocardial heart tube into pericardial cavity is such that lining Of pericardial cavity applied to the heart tube will form

Answer 9

visceral layer of serous pericardium (Epicardium),

Question 10

lining of the rest of the pericardial cavity will form

Answer 10

parietal layer of serous pericardium

Question 11

cavity of the original pericardial coelom will form the

Answer 11

pericardial cavity.

Question 12

Mesenchymal tissue around the pericardial cavity forms the

Answer 12

fibrous pericardium.

Question 13

lie outside the pericardial cavity

Answer 13

The cranial (Arterial) and caudal (venous) ends of the heart tube

Question 14

The fused endocardial heart tube (Tubular heart) splits into left and right parts and also gets divided into

Answer 14

primitive atrial and

ventricular chambers.

Question 15

Venous end of the heart tube (Sinus venosus) gets absorbed into the

Answer 15

right atrium.

Question 16

Arterial end of the heat tube (Truncus arteriosus) divides into.

Answer 16

ascending aorta and pulmonary trunks

Question 17

Blood flow in primitive heart

Answer 17

Sinus venosus
Sinostrial valve
Primordial atrium
Atrioventrcular
Ventricle 
Bulbous cord is
Truncus arteriosus
Aortic sac
Dorsal aorta

Question 18

The simple tubular heart develops enlargement

Answer 18

Atria and ventricles

Question 19

The simple tubular heart develops enlargement (Atria and ventricles) and constrictions

Answer 19

bulboventricular sulcus and

atrioventricular sulcus

Question 20

The simple tubular heart develops enlargement and constrictions and folds in such a way that,

Answer 20

ventricles lie in front of (Ventral) the atria, - and sinus venosus behind (dorsal) to atria.

Question 21

atrioventricular canal is a

Answer 21

single wide communication between primordial atrium and primordial ventricle

Question 22

Two thickenings, ventral and dorsal endocardial cushions develop in the atrioventricular canal in ventral and dorsal position.

Answer 22

T

Question 23

These endocardial cushions grow towards each other and fuse to form

Answer 23

fused endocardial cushion

Question 24

fused endocardial cushion which divides

Answer 24

the atrioventricular canal into right and left atrioventricular canals.

Question 25

———grows towards fused endocardial cushion form the roof of the primitive atrium.

Answer 25

Septum primum

Question 26

The passage between the lower end of the septum primum and fused endocardial cushion is the

Answer 26

foramen primum

Question 27

foramen primum which

Answer 27

shunts blood from right atrium to left atrium

Question 28

As the septum primum fuse with endocardial cushion, perforations appear in the upper part of the septum primum, to form

Answer 28

foramen secundum

Question 29

foramen secundum which

Answer 29

shunts the blood from right atrium to left atrium as the foramen primum is now closed.

Question 30

septum secundum develops on

Answer 30

the right side of septum primum. grows towards endocardial cushion

Question 31

septum secundum it overlaps the foramen secundum such that an oval opening formed between them

Answer 31

Foramen ovale,

Question 32

Foramen ovale, bounded by

Answer 32

lower free margin of septum secundum and upper free margin of septum primum

Question 33

With further growth of septum secundum, it overlaps the septum primum on right side and convert the foramen ovale into a

Answer 33

slit-valve like opening.

Question 34

When the blood pressure is increased in the right atrium (due to blood flow from sinus venosus into right atrium) flap like valve of foramen ovale (Septum primum), will deviate towards

Answer 34

left allowing the blood to flow to left atrium.

Question 35

After birth when the pressure in the left atrium is increased (due to blood returning to it from lungs through pulmonary veins), it will push the valve of foramen ovale (septum primum) against the thick free margin of the septum secundum there by closing the foramen ovale.

Answer 35

T

Question 36

The sinus venosus at the venous end of the heart tube receives blood from body of the

Answer 36

embryo (Cardinal veins), yolk sac( Viteline veins) and placenta (Umbilical vein).

Question 37

sinus venosus opens into to primitive atrium on its

Answer 37

posterior wall.

Question 38

Sinus venous will be absorbed into the wall of right atrium where it forms the

Answer 38

sinus venarum-smooth part of the right atrium.

Question 39

The pulmonary veins develop as an

Answer 39

outgrowth

Question 40

The pulmonary veins develop as an outgrowth from the- to—

Answer 40

atrial wall to the left of the septum primum.

Question 41

As the left atrium expands, the pulmonary veins are absorbed into the atrial wall such that,

Answer 41

two initial branches of pulmonary vein now open separately into left atrium.

Question 42

With further expansion of left atrium, pulmonary veins were further absorbed into atrial wall so that secondary branches of pulmonary veins (four in number) open directly into the left atrium.

Answer 42

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