CVS 2 Embryology- Early Development of the CVS Flashcards Preview

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Flashcards in CVS 2 Embryology- Early Development of the CVS Deck (20):
1

What develops from the cardiogenic field?

heart, blood vessels and blood cells

2

When is the cardiogenic field created?

during gastrulation

3

Where does the cardiogenic field lie before embryonic folding?

the cranial end

4

What does lateral folding do?

create the heart tube

5

What does cephalocaudal folding do?

bring the tube into the thoracic region

6

When does the pair of endocardial tubes develop?

3rd week of development

7

What are the different parts of the primitive heart tube?

Aortic roots
Truncus Arteriosus
Bulbus Cordis
Ventricle
Atrium
Sinus Venosus

8

Why does the looping (primitive heart tube bends) and when does it happen?

Continued elongation results in bending.
Begins around day 23 and finishes around day 28

9

What sinus does looping create?

Transverse pericardial sinus

10

How does the sinus venosus develop?

R and L horns orginally equal size
Venous return shifts to RHS so left sinus horn recedes
Right sinus horn ansorbed by enlarging RA

11

What does the right atrium develop from? What does it recieve?

Most of primitive atrium
sinus venosus
Receives venous drainage from body (venae cava) and heart (coronary sinus)

12

What does the left atrium develop from?

small portion of primitive atrium
absorbs proximal parts of pulmonary veins
recieves oxygenated blood from lungs

13

How is oblique sinus formed?

as left atrium expands absorbing pulmonary veins

14

How does fetus recieve oxygenated blood?

via placenta and umbilical vein. Returns to placenta via umbilical arteries

15

What is the ductus arteriosus?

shunt in fetal circulation between pulmonary trunk and aorta. Most blood doesnt pass through right ventricle and pulmonary trunk, it moves into left atrium but some must pass through to allow the muscle to develop

16

How do the aortic arches begin in the early arterial system?

a bilaterally symmetrical system of arched vessels numbered 1,2,3,4,6

17

What do the 4th arches form?

L- arch of aorta R- proximal part of right subclavian artery

18

What do the 6th (pulmonary) arches form?

R-right pulmonary artery L-left pulmonary artery and ductus arteriosus

19

What are the recurrent laryngeal nerves?

the nerve corresponding to the 6th arch moving down into chest then back up to larynx, controlling qualities of voice

20

What factors influence the course of the laryngeal nerves?

left hooks round the ductus arteriosus
caudal shift of developing heart and expansion of developing neck region