1

Development of the circulatory system

Movement of the heart into a ventral (subcervical) position

cardiogenic field

and dorsal aortae

merging of the ventral aortae,

formation of the heart tube

Aortic arches around foregut

Veins opening into sinus-horns:

- v. vitellina

- v. umbilicalis

- v. cardinalis communis

- v. cardinalis cranialis

- v. cardinalis caudalis

Sinus venosus collects blood

from the caudal direction,

and through truncus arteriosus

the blood gets into the aortic arches

2

Separation of atria and ventricles

Developmental phases:

ventral view

Developmental phases:

lateral view

Formation of septum intermedium

septum primum

ostium secundum septum secundum

ostium primum

foramen

ovale

Partial incorporation of sinus-horns into atria

3

Separation of the truncus arteriosus

Detachment of aorta and truncus pulmonalis

elkülönülése

Formation of papillary muscles and atrioventricular cusps

Formation of

semilunar

valves

4

Aortic arches

eq bo su

ca

aortic arches with n. vagus

and n. laryngeus recurrens

left

side

right

side

ventral view

During development these structure disappear: - I., II., V. and VI. aortic arches on the right side;

- I., II. and V. aortic arches on the left side;

- connection between III. and IV. aortic arches;

- connection between right dorsal aorta and the unpaired aorta.

5

Development of venous system

Changes in sinus-horns

dorsal view

sub

card

inal

vei

ns

left left

sup

raca

rdin

al v

ein

s d

isap

pea

rance

of

caud

al c

ard

inal

is v

eins

left

6

Changes in circulation

Developmental anomalies

Key points: intracardial changes (foramen ovale), pulmonary circulation and ductus arteriosus (Botallo-duct),

ductus venosus (Arantius-duct), a. umbilicalis (nutrients- and oxygen-poor blood transport to placenta), v. umbilicalis (fresh blood to fetus)

pat

ent

duct

us

arte

rio

sus

(PD

A)

pulm

onar

y

sten

osi

s

interatrial

septal defect

Fal

lot-

tetr

alo

gy

aort

aste

no

sis

interventricular

septal defect

persistent right aortic arch (PRAA)

together with left lig. arteriosum, and

consequential compression of oesophagus pulmonary stenosis + overriding aorta +

interventricular septal defect + dilatation and

hypertrophy of the right ventricle