cv development Flashcards
when and why does vascular system appear?
middle of third week
no longer to satifsty nutrition through diffusion alone
where is blood formed as development progresses? 1st - 0-3 mo 1 mo-birth 3-6 mo 4 mo-life
extra embryonic yolk sac liver spleen bone marrow
blood vessels form from
intraembryonic splanchnic mesoderm
intususseption
splitting of existing blood vessels
umbilical vein
is oxygen rich - brings blood to fetus from placenta
2 shunts used in utero to act as a single chambered heart
interatrial foramen ovale and ductus arteriosus
as embryo, circulation resistance in pulmonary system is____ and systemic is _____
after birth….
high
low
so pressure on right side of heart is higher but switches at birth due to shunt closure
development of atrial septum
septum primum w foramen primum–> foramen secundum –> septum secundum on the right side of septum primum –> foramen ovale (eventually fossa ovalis
septum secundum = membranus valve
foramen secundum/septum primum = foramen
embryonic blood flow
venacava –> right atrium and ventricle –> pulmonary artery –> ductus arteriosus into aorta
due to high resistance in pulmonary arteries, only a little goes to lungs
oxygenated blood from ubilical a tends to stream across atria thru foramen ovale bypassing lungs – mixed blood spread through body
before embryo folding, primary heart field is …
superior to head
truncus arteriosus becomes…
ascending aorta and pulmonary artery
bulbus cordis becomes…
outflow tracts of ventricles and trabecular walls of RV
sinus venosus becomes …
coronary sinus and smooth wall of right atrium
when does cardiac looping occur
4th wk –> puts 4 chambers in right spot
what type of cells form truncus arteriosus septum?
neural crest
o Neural crest cells also form face and head migration issues will display heart and head defects!
