Development of cardiovascular system

Question 1

The bilaminar germ disc layers are called what?

Answer 1

Top layer- epiblast
Bottom layer- hypoblast

Question 2

The conversion of the bilaminar germ disc into a trilaminar germ disc is called what?

Answer 2

Gastrulation

Question 3

The mesodermal layer has 3 parts- what are they

Answer 3

Paraxial mesoderm
Intermediate mesoderm
Lateral plate mesoderm

Question 4

What are the 3 layers of the trilaminar germ disc superficial to deep?

Answer 4

Ectoderm
Mesoderm
Endoderm

Question 5

Paraxial mesoderm gives rise to the what?

Answer 5

Somites

Question 6

The lateral plate mesoderm has two layers to it. What are they?

Answer 6

Somatic/parietal
Visceral/splanchnic

Question 7

What is the groove that leads to the trilaminar germ disc formation from the epiblast?

Answer 7

Primitive Streak

Question 8

Cells that sit bilaterally to the primitive streak that contribute to the heart tissue are?

Answer 8

Epiblast cells

Question 9

The epiblast gives rise to the??

Answer 9

Ectoderm

Question 10

The ______________, start off in the epiblast in the Bilaminar germ disc . But by the time the trilaminar germ disc is formed, they migrate down an settle into the splanchnic mesoderm.

Answer 10

progenitor heart cells

Question 11

The primary heart field PHF forms from the epiblasts in between what layers of the trilaminar disc?

Answer 11

Splanchnic mesoderm (superior)
Endoderm (inferior)

Question 12

the PHF moves from its original cranial position (anterior) to the thoracic region as a result of ____________ folding and the _________ foldings.

Answer 12

cephalocaudal; lateral

Question 13

What are the 3 stages of heart formation?

Answer 13

1. Formation of primitive heart tube
2. Cardiac looping
3. Cardiac septation

Question 14

the Left & Right endocardial tubes fuse together to become the ??? at day 22

Answer 14

primitive heart tube

Question 15

The heart tube is attached to the dorsal wall of the pericardial cavity (suspended in the cavity) by a layer called the ???

Answer 15

Dorsal mesocardium

Question 16

Dorsal mesocardium is derived from the ___________ (which originates from the splanchnic mesoderm).

Answer 16

secondary heart field (SHF)

Question 17

The myocardium secretes a layer of extracellular matrix called ??????

Answer 17

cardiac jelly (collagen, GAGs, glycoproteins)

Question 18

Cardiac jelly does what?

Answer 18

regulating cell shape, migration, proliferation, and differentiation of the heart cells, has growth differentiating factors

Question 19

Before the heart tube loops, it first ______

Answer 19

lengthens

Question 20

As the outflow tract lengthens, the cardiac tube begins to loop. The cephalic portion of the tube bends ______ moving caudally to its ___________.
The caudal portion shifts _________, cranially to its ________

Answer 20

ventrally; right

Dorsally; left

Question 21

The bending of the cardiac tube results in the ______

Answer 21

Cardiac loop

Question 22

What is the process of cardiac septum forming called

Answer 22

Cardiac septation

Question 23

What are the two ways of septum formation?

Answer 23

1. Two active growing masses (endocardial cushions) approach each other until they fuse, dividing the lumen into separate chambers.
2. A single tissue mass grows until it reaches the opposite side of the lumen (ex. the formation of the septum primum and septum secundum)

Question 24

The truncus arteriosus is the precursor to what two vessels?

Answer 24

Pulmonary artery & dorsal aorta

Question 25

The endocardial cushion protrusions help form what 3 things?

Answer 25

-Atrial & ventricular septums -Atrioventricular canals & valves -Openings of the aortic & pulmonary channels

Question 26

What is the name of the tissue in the forming heart that separates the common atria into right and left?

Answer 26

Septum Primum

Question 27

What is the name of the fold from the dorsal atrial myocardium, begins forming from the cranial aspect of the atria, and forms the roof of the foramen ovale? This will eventually fuse with the septum primum to close the foramen ovale and complete atrial septation after birth.

Answer 27

Septum Secundum

Question 28

This allows oxygenated blood to pass from the right atrium to the left. The septum primum will continue to grow, fusing with the endocardial cushions and obliterating this structure. Once this disappears, the septum primum has formed the primordial atrioventricular septum.

Answer 28

Foramen Primum

Question 29

The formation of what structure is the signal for the formaen primum to fully close and form the primordial AV septum?

Answer 29

Foramen secundum

Question 30

Once the septum secundum is formed, a new feature is made, and this completes the division of the 2 atrial chambers. What is the new feature?

Answer 30

Foramen ovale

Question 31

What is the structure that divides the truncus arteriosus internally so that the pulmonary artery is connected to the right ventricle and the dorsal aorta to the left ventricle?

Answer 31

Spiral Septum

Question 32

What force do the lungs perform on the heart while they are still developing?

Answer 32

Gives a negative force against the vessels so blood does not flow to an undeveloped lung

Question 33

Where does oxygenated blood come from in a fetal heart?

Answer 33

through the IVC via the placenta

Question 34

Vessels arising from angioblasts

Answer 34

Vasculogenesis

Question 35

vessels sprout from existing vessels

Answer 35

Angiogenesis

Question 36

The major vessels, including dorsal aorta & cardinal veins, are formed by

Answer 36

vasculogenesis

Question 37

The entire circulatory system is patterned by guidance cues involving

Answer 37

Vascular endothelial growth factor (VEGF)