Great Vessel Development Flashcards
What are the major mechanisms by which the vascular plexus expands?
vasculogenesis
angiogenesis
intussuption
vasculogenesis
new vessels
angiogenesis
branching
intussuption
splitting
angiomas
abnormal blood vessels and lymph growth
capillary hemangioma
small capillary network
cavernous hemangioma
venous sinuses
hemangiomas of infancy
benign endothelial cell tumors
What are pharyngeal arches made of?
outgrowths of head and neck mesenchyme
What do pharyngeal arches contain?
cranial nerve and artery – aortic arches
What do aortic arches (AA) arise from?
aortic sac - expansion at distal most portion of truncus arteriosus
What do the aortic arches connect?
aortic sac with dorsal aorta
What are the aortic arches formed by?
angiogenesis and vasculogenesis
What aortic arches hypertrophy?
3, 4, 6
What vessels are added to primitive aortic arch system?
external carotid, distal part of pulmonary artery
What aortic arches are lost?
1, 2 [5 never forms]
What level do paired dorsal aorta fuse?
T4
What divides the aorta and pulmonary artery?
aorticopulmonary septum
How do intersegmental arteries form?
vasculogenesis within mesoderm
How many intersegmental arteries are there in each section?
7 cervical
12 thoracic
5 lumbar
What happens to the 7 cervical intersegmental arteries?
lose roots of 1-6, longitudinal anastamosis becomes vetebral arteries
left 7th intersegmental artery - forms subclavian artery
right 7th intersegmental artery - forms part of subclavian artery with AA IV
What happens to the 12 thoracic intersegmental arteries?
superior/inferior anastamoses fofrm internal thoracic arteries
intersegmental arteries form intercostal arteries
What happens to the 5 lumbar intersegmental arteries?
anastamosis makes epigastric and iliac vessels
What happens to AA I and II?
break up and reorganize
I - maxillary A
II - stapedial A
What happens to AA III?
main feeder to head, forms common carotid and proximal portion of internal carotid
remainder becomes dorsal aorta
sprouts to form external carotid
What happens to AA IV? Left? Right?
hypertrophies
Left - forms part of aortic arch (2nd part)
Right - proximal part of subclavian A
What insures connection of left AA IV to left ventricle?
spiral septum of outflow tract
What forms the aortic arch in the newborn?
Aortic sac, AA IV, left dorsal aorta proximal to 7th intersegmental, left dorsal aorta distal to 7th intersegmental
What happens to AA V?
never forms
What happens to AA VI?
pulmonary arteries (along with aortic sac)
Where does the heart start to grow?
cervical region
Where does the heart end up?
thorax
What causes the laryngeal nerve to become hooked around the future right subclavian?
regression of distal part of right AA VI (loss of connection to right dorsal aorta)
What is the connection between the dorsal aorta and AA VI called on the left?
ductus arteriosus
What nerve is hooked around the distal AA VI?
recurrent laryngeal N
What happens to the left distal AA VI?
ligamentum arteriosum
What happens to the dorsal aorta?
carotid duct (portion between AA III & AA IV) disappears. Right dorsal aorta disappears btwn right 7th intersegmental A and junction with left dorssal aorta. remaining segments fuse to form descending thoracic and abdominal aorta.
What do the vitelline arteries form?
GI vasculature
What do umbilical arteries form?
developing bladder arteries
distal end disappear after birth and become medial umbilical ligaments
proximal 5th lumbar intersegmental arteries - referred to as umbilical arteries in adult
What causes the ductus arteriosus to close after birth? When does it close?
changes in blood oxygen tension, sudden drop in prostaglandin, increase in endothelin release from newborn lungs.
10-15 hours after birth
Patent ductus arteriosus
1/3-1/2 blood traveling via aorta will enter pulmonary artery b/c systemic BP is higher. blood will circulate 2-3 times. LV hypertrophy. Pulmonary congestion and CHF. Blowing murmur after 1-3 years.
What increases the risk for patent ductus arteriosus?
maternal rubella infection during early pregnancy
What is the treatment for patent ductus arteriosus?
prostiglandin inhibitors (indomethacin) or surgery
What is coarctation of the aorta?
narrowed aortic lumen below left subclavian A due to abnormal thickening of aortic wall
____ is more frequent in Turner’s syndrome.
Coarctation of the aorta
postductal coarctation of the aorta
sometimes not noticed b/c collateral circulation is established through intercostal arteries
preductal coarctation of the aorta
collaterals not well developed, little or no blood to lower body and legs unless ductus arteriosus remains open (and even then O2 poor from RV). Death if severe w/o surgery.
What forms wrong in aberrant origin of right heart?
What disappears?
Symptoms?
Why?
subclavian formed by distal portion of right dorsal aorta and 7th intersegmental A instead of 7th intersegmental A and right AA IV
Right AA IV and right dorsal aorta disappear
symptoms: dysphagia and dyspnea
right dorsal aorta crosses esophagus to right UE
What causes double aortic arch?
Symptoms?
vascular ring surrounding trachea and esophagus
symptoms: esophageal dysfunction and strangulation of trachea
What causes right aortic arch?
symptoms?
What causes symptoms?
left AA IV and left dorsal aorta gone and replaced with right
symptoms: dysphagia and dyspnea if left subclavian A passes behind esophagus and ligamentum arteriosum passes in front of trachea
What causes interrupted aortic arch?
What is this associated with?
Is it life threatening?
AA IV disappears and proximal part of right dorsal aorta disappears
ductus arteriosus remains open
low O2 in descending aorta and subclavian As
DiGeorge syndrome
yes
What do the vitelline veins drain?
yolk sac
What do the vitelline veins form?
vascular plexus hepatic sinusoids within liver primordia
What does the right proximal vitelline vein turn into?
right hepatic cardiac channel then terminal part of inferior vena cava
What does the left proximal vitelline vein turn into?
nothing, disappears
What does the left inferior vitelline vein turn into?
portal vein, superior and inferior mesenteric veins, splenic veins
What is the function of the umbilical veins?
carry oxygenated blood from the placenta to the fetal heart
What is the channel between the left umbilical vein and right hepatocardiac channel?
ductus venosus
What is the function of the ductus venosus?
oxygenated blood bypasses sinoidal plexus of liver
What keeps the ductus venosus open?
prostaglandins
What happens to the left umbilical vein and ductus venosus after birth?
disappears forming ligamentum teres hepatis and ligamentum venosum
What drains the blood from the head and neck into the cardinal veins on the right side?
anastamoses between left and right anterior cardinal veins
What does the anterior cardinal vein form?
anastomoses between right and left - left brachiocephalic vein
right common cardinal vein - SVC
What makes the coronary sinus?
left cardinal vein and left sinus horn
What can abnormal anterior cardinal vein development lead to?
superior vena cava draining into the heart via coronary sinus
What do the posterior cardinal veins connect?
subcardinal and supracardinal veins
What do the subcardinal veins form?
kidney and gonal veins, abdominal IVC
Whta do the supracardinal veins form?
portions of IVC, azygos system, and veins draining body wall
