lect 7 & 8-development of heart, vasculature, and lympathics Flashcards
what is the cardiovascular system derived from
mesoderm
what occurs on day 16 of cardiovascular system development
epiblast cells migrate to lateral splanchnic mesoderm
what does FGF8 from the node upregulate
NODAL
why is NODAL restricted to the left side
accumulation of 5-HT on left side
why can’t NODAL cross the midline
due to SHH and Lefty1
what do nodal proteins upregulate
PITX2
what does PITX2 do
gene that codes for a transcription factor that specifies left-sidedness
what is transcription factor inappropriately expressed on the right side leads to situs inverses and dextracardia
PITX2
what is the most cranial cardiac bulge
truncus arteriosus
what is the most caudal cardiac bulge
sinus venosus
what day does the heart begin to pump
Day 22
where is the first flexure of the bulboventricular loop
between the bulbs cordis and primitive ventricle
where does the second flexure of the atrioventricular loop occur
between ventricle and primitive atria
how do primitive atria move
cranial and caudally
when does atrial partitioning begin
day 30
what does the trabeculated bulbs cords become
right ventricle
why does dextracardia occur
inappropriate heart looping
what does the left horn of the sinus venosus become
coronary sinus
what does the right side of the sinus venosus become
sinus venarum
what do pulmonary veins develop from
left atrium
what is the most important transcription factor for partitioning of the AV canal
Retinoid acid
when does persistent AV canal occur
when the AV endocardial cushions fail to fuse
what cardiac disorder is common in individuals with down syndrome
persistent AV canal
what disorder is characterized by a single large valve (as opposed to the tricuspid and mitral valves), causing blood to shunt from the left ventricle to the right, elevating pulmonary pressure
complete AV canal defect
what does the septum primum form from
roof of atrium
what forms at the free edge of the septum primum
foramen (ostium) primum
where does the foramen ovale form
between the upper septum secundum and lower septum primum
how is blood shunted from the right atrium to the left in the embryo
via foramen ovale
why does the flow through the foramen ovale stop after birth
due to increase in left atrium pressure (caused by increased pulmonary return)
what occurs due to a premature closure of the foramen ovale
right side of the heart hypertrophies and left atrophies (usually fatal shortly after birth)
what occurs with membranous ventricular septal defect
faulty fusion of membranous septum leaves opening between left and right ventricles. there is initially a left-right shunting of blood, but pulmonary hypertension increases and reverses it to right a right-left shunting (late onset is eisenmenger complex)
what is the middle part of the bulbs cordis
conus cordis
what is the distal part of the bulbs cordis
truncus arteriosus
what divides the truncus and conus into 2 canals
a sheet of neural crest cells that spirals longitudinally
describe persistent truncus arteriosus (PTA)
results in one large vessel that receives blood from both the right and left ventricles (usually accompanied by VSD and cyanosis)
what are the factors of the tetralogy of fallot
increased outflow in aorta
thickened right ventricle (hypertrophy)
partial obstruction (stenosis) of right ventricular outflow and pulmonary valve)
VSD
how is tetralogy of ballot diagnosed in utero
by ultrasound
where is SA node initially located
in the sinus venosus wall
when do sympathetic and parasympathetic nerves of the heart system arrive
day 30
what does the trunks arteriosus give rise to
ascending aorta and pulmonary trunk
what does the bulbus cords give rise to
outflow tract (smooth parts) of right and left ventricle
what does the primitive atria give rise to
trabeculated part of right and left atria
what does the primitive ventricle give rise to
trabeculated part of right and left ventricle
what does the left horn of the sinus venosus give rise to
coronary sinus
what does the right horn of the sinus venosus give rise to
smooth part of right atrium
what is the vitelline circuit
dorsal aorta to vitelline arteries to yolk sac (vitelline veins return blood from yolk sac)
what is the umbilical circuit
umbilical arteries carry poorly oxygenated blood from embryo to chorion
where does gas exchange occur in the embryo (since lungs are not functional)
chorion
what are a serious of invaginations lined by ectoderm that form on the ventral (external) surface
pharyngeal clefts
what are a series of endoderm lined sacs that separate arches dorsally (internally)
pharyngeal pouches
what adult structures does the 3rd aortic arch give rise to
common carotid and 1st part of internal carotid
what adult structures does the 4th left aortic arch give rise to
arch of aorta
what adult structures does the 4th right aortic arch give rise to
right subclavian
what adult structures does the 6th leftaortic arch give rise to
left pulmonary and ductus arteriosus
what adult structures does the 6th right aortic arch give rise to
right pulmonary
what is the channel linking the pulmonary artery with the aorta in the fetus that bypasses the fluid filled lungs
dusts arteriosus
what does the ductus arteriosus persist as
ligamentum arteriosus
what failure occurs when patent ductus arteriosus occurs
failure of ductus arteriosus to close after birth
what are the symptoms of patent ductus arteriosus
rapid breathing, rapid pulse, fatiguability
how is patent ductus arteriosus diagnosed
EKG
what is the treatment for patent ductus arteriosus
indomethacin (NSAID) or surgery
what is the issue with a double aortic arch
there is persistence of the right dorsal aorta caudal to the 7th intersegmental artery that forms a ring around the trachea and esophagus
what are the symptoms of coarctation of the aorta
hypertension in upper extremities, delay between brachial and femoral pulse, hypotension (or absence of pulses) in lower extremities
what is the adult derivative of the vitelline arteries
celiac, superior mesenteric and inferior mesenteric arteries
what is the adult derivative of the umbilical artery
medial umbilical ligaments
what shunts oxygenated blood to the heart
ductus venosus
what does the ductus venosus constrict into after birth
ligamentum venosum
what vitelline vein persists
right
which umbilical vein persists
left
what are the adult derivatives of the vitelline veins
IVC, hepatic veins and sinusoids, portal vein, inferior and superior mesenteric veins, splenic vein
what is the adult derivative of the left umbilical vein
ligamentum teres
what is the adult derivative of the anterior cardinal vein
SVC, internal jugular veins
what is the adult derivative of the posterior cardinal vein
IVC, common iliac veins
what are the adult derivatives of the sub cardinal vein
IVC, renal and gonadal veins
what are the adult derivatives of the supra cardinal vein
IVC, hemiazygos, azygos
what system do the cardinal veins form
caval system
what system do the vitelline veins form
hepatic portal system
what is the critical first step in the development of the 4-chambered heart
formation and fusion of endocardial cushions
what is the foramen ovale derived from
septum primum
what does the liver develop in
septum transversum
what connects the umbilical vein with IVC
ductus venosus
when is the cardiac loop completed
day 28
what transcription factor plays important role in septation
TBX5
when does the common cardinal vein obliterate
10th week
what forms the dividing line between the original trabeculated part of the right atrium and the smooth-walled part
crista terminalis
what is the opening between the lower rim of the septum priming and the endocardial cushions
osmium primum
what does the pulmonary vein develop within
DMP
where does the pacemaker of the heart originally lie
in the caudal part of the left cardiac tube
what is the superior mesenteric vein derived from
right vitelline vein
what is the closure of the ductus arteriosus regulated by
bradykinin
what occurs when the tricuspid valve is displaced towards the apex of the right ventricle, resulting in an expanded right atrium and a small right ventricle
epstein anomaly
what disease occurs due to a 22q deletion and have facial defects, thymic hypoplasia, parathyroid dysfunction, and cardiac abnormalities involving the outflow tract
DiGeorge Syndrome
where does type A interrupted aortic arch occur
between the left subclavian artery and the descending aorta
where does type B interrupted aortic arch occur
between the left common carotid and left subclavian arteries
where does type C interrupted aortic arch occur
between the right and left common carotid arteries
