Lecture 23: Great Vessel Development Flashcards
Where do aortic arches arise from?
Aortic sac
-distal most portion of truncus arteriosus
Where are aortic arches formed?
Within the pharyngeal arches by vasculogenesis and angiogenesis
Where do the dorsal aorta fuse?
What direction does it continue in?
T4 axial level
-continues caudally
What divides into aorta and pulmonary arteries?
Truncus arteriosus
What are intersegmental arteries?
Set of arteries arising from the embryonic dorsal aorta
-each artery providing blood supply to one somite and its derivatives
Cervical intersegmental arteries are united by longitudinal anastomoses and give rise to what artery?
Vertebral artery
The 7th cervical intersegmental artery on both sides give rise to what artery?
Subclavian Artery
- left side: all of it
- right side: part of it
What do the anastomoses between thoracic intersegmental arteries give rise to?
Internal Thoracic Artery
What do the thoracic intersegmental arteries themselves give rise to?
Anterior and Posterior intercostal arteries
What does the 5th lumbar intersegmental artery give rise to?
Common Iliac Artery
What does the 3rd aortic arch give rise to?
Common Carotid: both external and internal
What does the left 4th aortic arch give rise to?
Forms part of aortic arch
-connected to left ventricle via spiral septum of outflow tract
What does the right 4th aortic arch give rise to?
Brachiocephalic trunk and part of right subclavian artery
What does the 6th aortic arch give rise to?
Pulmonary arteries
Why do the right and left recurrentl laryngeal nerves differ?
Right aortic arch VI loses connection with dorsal aorta and its recurrent laryngeal nerve is hooked around future right subclavian artery
Left aortic arch VI has ductus arteriosus that becomes ligamentum arteriosum, which hooks left recurrent laryngeal
After birth, the distal end of umbilical arteries is obliterated and becomes what?
Medial umbilical ligaments
What branches of the umbilical artery and supplies the superior portion of the bladder?
Superior vesicular arteries
How does oxygen rich blood bypass most of the liver and enter inferior vena cava and right ventricle?
via ductus venosus
What does the ductus venosus eventually become?
Ligamentum venosum
How does blood shift from right atria to left atria?
via foramen ovale
How does blood from pulmonary trunk enter descending aorta?
via ductus arteriosus
What does the ductus arteriosus become?
Ligamentum arteriosum
What keeps ductus arteriosus open?
Prostaglandins
Certain oxygen levels
What are some consequences of patent ductus arteriosus?
Left ventricular hypertrophy
- pulmonary congestion
- congestive heart failure
What can cause an increase risk of patent ductus arteriosus?
Maternal rubella infection
What is coarctation?
Narrowing of the aorta
What syndrome is coarctation associated with?
Turner Syndrome
How can circulation be compensated with in a postductal coarctation?
Collateral circulation is established through intercostal (intersegmental) arteries and internal thoracic arteries
Why is preductal coarctation dangerous?
- Collaterals usually not well developed
- After birth, little or no blood gets to lower body and legs unless ductus arteriosus remains open
How does an aberrant origin of right subclavian artery form?
Right 4th aortic arch is eliminated, meaning the right dorsal aorta must cross esophagus to reach right upper limb
Describe a double aortic arch.
Aorta wraps around trachea and esophagus can cause strangulation
-abnormal formation called a vascular ring
Describe a right aortic arch.
Left 4th aortic arch and dorsal aorta disappears and replaced by structures on the right
-dysphagia and dyspnea are common symptoms
Describe an interrupted aortic arch.
Left 4th aortic arch disappears
- ductus arteriosus remains and lower parts of body are supplied with poor oxygen content
- aortic trunk supplies two common carotid arteries
With what syndrome is an interrupted aortic arch associated with?
DiGeorge Syndrome
What does the vitelline system do?
Carries blood from yolk sac to sinus venosus
What does the umbilical system do?
Carries oxygen rich blood from placenta
What does the cardinal system do?
Drain the body of embryo
Describe what happens to vitelline veins?
- Initially empty into sinus horns
- Surrounded by liver primordia
- Vitelline veins form vascular plexus (hepatic sinusoids)
- Blood flow channeled twd right side of liver
- Proximal portion of right vitelline vein –> IVC
Right vitelline vein forms the right _____ ____ that eventually forms the terminal part of the inferior vena cava
hepatocardiac channel
Inferior parts of vitelline veins help contribute to form what veins?
Portal vein
Superior and inferior mesenteric vein
Splenic vein
Which umbilical vein carries placental blood to liver?
Left
What is the ductus venosus?
Direct communication between left umbilical vein and right hepatocardiac channel that allows most of the blood to
bypass the sinusoidal plexus of liver
What does the umbilical vein eventually become?
Ligamentum teres
The anterior and posterior cardinal veins form what
Common cardinal vein before entering the sinus horn
The anterior cardinal veins drain what?
Most of the blood from the head and neck into cardinal veins on right side
An anastomosis between right and left anterior cardinal vein forms what?
Left brachiocephalic vein
Right common cardinal vein forms what?
SVC
If there is abnormal anterior cardinal vein development, the SVC might drain where instead of the right atria?
Coronary sinus
Posterior cardinal veins connect which two parallel set of veins?
Subcardinal
Supracardinal
What do subcardinal veins contribute to?
Veins of kidneys and gonads
Abdominal IVC
What do supracardinal veins contribute to?
IVC
Azygous system
Veins draining body wall
