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!
if conoseptal ridges dont spiral when fusing, what defect?
transposition of great vessels
vitelline system becomes
GI veins
no #__ of aortic arches
5
heart tube begins to beat,,,,
before looping
before looping, heart tube top to bottom…
truncus arteriosus bulbus cordis ventricle atrium sinus venosus
heart is the first organ to display
left right asymmetry
recurrent laryngeal nerves form from…
6th pharyngeal arch
oygen tension and bradykinin
bradykinin from lungs imcreases and causes smooth muscle constriction of ductus arteriosus
