histology and embryololgy Flashcards
2 main types of arteries
elastic
muscular
difference between elastic and muscular arteries
elastic have more elastic tissue to withstand high pressure such as aorta
muscular have more smooth muscle - for vasodilation / vasoconstriction
function of arterioles
smaller than arteries
can control blood flow into capillary beds
site of most total peripheral resistance
structure of veins
three muscle layers
tunica adventitia, tunica media and tunica intima
function of capillaries
connect arterioles to venules
allow exchange of nutrients
function of intercalated discs
hold adjacent cells together by adhesion with desmosomes
allows impulses to travel rapidly as they have gap junction for depolarisation
when and what are the three trilaminar discs made
3rd week
ectoderm
mesoderm
endoderm
what do the three layers of trilaminar disc give rise to
ectoderm- skin , hair NS
meso- all muscle, cv system ug system
endo- liver pancreas , intestinal tube
what do the 6 aortic arches give rise to
1- maxillary artery 2- stapedial artery 3- common corotid 4- right subclavian branches 5- nothing 6- right pul trunk left- ductus arteriosus
how are the atria and ventricles split
atria- septum primum in an inferior direction
ven- interventricular septum in a superior direction
what is vasculogenesis
formation of blood vessels in the embryo by de novo production of endothelial cells.
foetal circulation to post natal circulation
expands the lungs causing pulmonary vasodilation which reduces
pulmonary pressure. As the ductus arteriosus is no longer needed, the pulmonary
shunt closes, increasing left atrial pressure, which causes the foramen ovale to close
what do the first and second heart fields develop into
first lv
second lv
Foetal remanants are what adult structured
What does the bulbuls cord is develop into
Right ventricle
