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Flashcards in Development of the Heart Deck (38):
1

When does the cardiovascular system develop

It is the first system to functionally develop
Happens btw 1st and 8th week
Mainly develops during middle of 3rd week

2

When does blood start to circulate

Beginning of the 4th week

3

How does the heart get to ventral surface of embryo

Head fold
Brings heart and pericardial cavity ventral to foregut

4

When does heart begin to beat

22-23 days

5

Truncus Arteriosus

Outflow of developing heart
Continuous with aortic sac

6

Bulbus Cordis

Outflow of developing heart
Proximal to truncus arteriosus

7

Sinus Venosus

Receives veonous blood flow from chorion, yoik sac, and embryo
Will develop right and left horns

8

Bulboventricular Loop

Bulbus cordis and primitive ventricle develop faster than other regions so the heart bends upon itself
Bends down and to the right
Sets up inflow and outflow

9

Inflow

Posterior - Back

10

Outflow

Anterior - Front

11

Blood Flow through Primordial Heart - Caudally to Cranially

1. Sinus Venosus
2. Primordial Atria
3. Atrioventricular Canal
4. Primordial Ventricle
5. Bulbus Cordis
6. Truncus Arteriosus
7. Aortic Sac
8. Aortic Arches

12

Partitioning of heart...when?

Begins middle of 4th week and is done by end of 5th

13

Development of semilunar valves

develop from three swellings of subendocardial tissue
position of the cusps after rotation is normal anatomical way of naming

14

Pulmonary Semilunar Valves

Right, Left and Anterior Cusps

15

Aortic Semilunar Valve

Right, Left and Posterior Cusps

16

Development of AV Valves

Proliferation of endocardial cushions around AV canals

17

Goal of Septum Primum

Close the foramen primum
Grows inferiorly to atrioventricular juntion

18

Goals of Septum Secundum

Overlap the foramen secundum
Overlapping forms flap like valve - foramen ovale

19

Formation of Right Atrium

Sinus Venosus develops left and right lateral horns
Right - becoems sinus venarum (smooth part of RA)
Left - becomes coronary sinus

20

Crista Terminalis

Junction between the right horn of sinus venosus (smooth) and the right side of primitive atrium (pectiante muscle)

21

Formation of Left Atrium

All smooth - more and more blood coming in, pulmonary vein gets bigger and is incorporated into LA
Smooth because of original pulmonary vein - used to be a blood vessel
Primitive gets pushed anteriorly and becomes the auricle (only rough place with pectinate)

22

Total Anomalous Pulmonary Vein

Congenital Defect
Primordial pulmonary vein gets incorporated into right side of developing interatrial septum therefore draining into right atrium instead of the left

23

Muscular Portion of IV Septum

Grows up (cranially) to meet the membranous portion
Divides the primitive ventricle into right and left side

24

Membranous Portion of IV Septum

Derived from tissue off the right side of endocardial cushion and aorticopulmonary septum

25

Membranous and muscular portions of IV form...

Permanent partition btw left and right ventricles

26

The twist is directed by...

blood flow!

27

Aorticopulmonary Septum

When the two vessels close you get the aorta and pulmonary trunk from the aorticopulmonary septum

28

Enodcardial Cushions

Presence is required to form the AV valves - seal the formation of the two outflow tracts

29

Fetal Circulation - 2 bipasses

1. right to left shunt - foramen ovale - foramen is closed when lungs get utilized
2. Ductus arteriosus - btw pulmonary trunk and aorta

30

Atrial Septal Defect

Issue with the 2 septums and 2 holes

31

ASD - Propaton

There is overlap but no fusion
Not clinical - fusion is high enough to keep it closed

32

Primum Type ASD

Septum primum didn't go all the down

33

Secundum Type ASD

Not enough overlap btw secundum foramen and septum

34

Ventricular Septal Defect

Membranous part where 3 things were supposed to meet in same plane at same time...
Oxygen not getting to body - blue baby

35

Persistent Truncus Arteriosus

Septum gets pushed away from midline so never meet up and cushions have nothing to seal

36

Transposition of Great Vessels

Aorta sitting over RV and pulmonary trunk sitting over LV
Didnt get 180 twist

37

Unequal division of truncus arteriosus

Pulmonary Septum
Aorticopulmonary septum is sent off to pulmonary side and tunk gets smaller than the aorta --> Tetralogy

38

Tetralogy

Guaranteed VSD, pulmonary stenosis, and smaller pulmonary artery so aorta compensates and gets huge --> overriding aorta siting over the septal defect