Great Vessel Development Flashcards
1
Q
What do the aortic arches arise from?
A
Arteries that arise from aortic sac
2
Q
What was the aortic sac an expansion of?
A
The most distal portion of the Truncus Arteriosus
3
Q
How many “pairs” of aortic arches are there?
A
6 -but really 5
4
Q
Where are aortic arches formed within and how?
A
W/in PAs by vasculogenesis and angiogenesis
5
Q
What are the 3 changes made to the primitive system to get to the adult system?
A
- Hypertrophy of some vessels (AAs 3,4,6)
- Addition of new vessels
- Loss of some vessel segments
6
Q
Where will the paired dorsal aorta begin to fuse at ?
A
At T4 axial level and continues caudally
7
Q
How is the truncus arteriosus divided?
What into
A
By aorticopulmonary septum
Into aorta and pulmonary a.
8
Q
How do intersegmental arteries form? Where?
A
Via vasculogenesis w/in paraspinal mesodern
9
Q
What do intersegmental as. Run b/w?
A
B/w somites
10
Q
How many cervical, thoracic, and lumbar intersegmental as. Are there?
A
Cervical: 7
Thoracic: 12
Lumbar: 5
11
Q
How are the cervical intersegmentals united?
A
By longitudinal anastomosis
12
Q
Which cervical intersegmentals go away?
A
Roots of 1-6
Only root of 7 remains
13
Q
Where vessels are derived from the longitudinal anastomoses of the cervical intersegmentals?
A
Vertebral As.
14
Q
What will the LEFT 7th cervical intersegmental a. Form?
A
L. Subclavian
15
Q
What will the RIGHT 7th cervical intersegmental form?
A
Portion of R. Subclavian
16
Q
What will the anastomosis b/w supeiror and inferior thoracic intersegmentals form?
A
Internal thoracic as.
17
Q
What do the anastomoses b/w thoracic intersegmentals themselves form?
A
Posterior and anterior intercostal as.
18
Q
What will the lumbar intersegmental anastomoses make?
A
Epigastric and Iliac vessels
19
Q
What will AA1 form?
A
Maxillary a.
20
Q
What will AA2 form?
A
Stapedial a.
21
Q
What will AA 3 form?
What is this arch called?
A
Carotid arch
-forms common carotid with split leading to Internal Carotid and External Carotid
22
Q
What will happen to AA 4?
A
Will hypertrophy so has both L and R side
23
Q
What will the L. AA 4 form?
A
Part of aortic arch
24
Q
What else helps to form the aorta?
A
Aortic sac - asc. Aorta
AA4 - artic arch
L. Dorsal aorta —> desc. And thoracic
25
What will connect the L. AA 4 with the LV?
Spiral septum of outflow tract (conotruncal ridges)
26
What does the RIGHT AA 4 form?
Proximal part of right subclavian
27
What 3 things help make the RIght subclavian a.?
1. R. AA 4
2. Dorsal aorta
3. . R. 7th intersegmental a.
28
What will AA 6 form?
Pulmonary As. (Also some help from aortic sac)
29
Where will outgrowths of AA6 go to?
Enters mesenchyme of lung
30
The R. AA6 connection to the dorsal aorta disappears, but what will the L. One form?
Will form ductus arteriosus (and eventually ligamentum arteriosum)
31
Why does the recurrent laryngeal n. From vagus appear to arise at 2 different axial levels? (One around aortic arch and one around r. Subclavian)
Bc. Heart moves to thorax as embryo grows and carotid lengthen so that subclavian ends up lower now
- connect from R AA 6 to dorsal aorta lost, R. Recurrent laryngeal now wrapped around r. Subclavian a.
- ductus arteriosus there, so L. Recurrent laryngeal around aortic arch and L. Art.
32
What are the vitelline arteries?
What will they eventually form?
◦ Vessels supplying yolk sac
eventually form the GI vasculature
33
What are the umbilical as.?
◦ Paired ventral branches of dorsal aorta that course
to placenta and have connections w/ developing bladder
34
What will the 5th lumbar A. Form ? (2)
- internal iliac a.
| - connection b/w it and umbilical a.
35
What birth what will the distal end of the Umbilical a. Form?
Will becomes medial umbilical Ls.
36
What arteries branch off the 5th lumbar intersegmental As. (Iliac vessles) in adults?
To supply what?
Superior vesicular arteries to supply bladder
37
What are the 3 main vein systems in the embryo?
1. Vitelline
2. Umbilical
3. Cardinal
38
What i the function of vitelline veins?
• Carries blood from yolk sac —> sinus venosus (primordium of RA)
39
What is the function of the umbilical system?
Where does it originate ?
• Originates in chorionic villi of placenta carrying O2-rich blood
40
What is the funciton of the cardinal vein system?
Drains the body of the embryo
41
What is the path of the Vitelline veins after they empty into the sinus horns?
Pass thru septum transversum where they become surrounded by liver primordia
42
What happens to the Vitelline veins as the liver develops?
Veins will form vascular pelxus of HEPTIC SINUSOIDS w/in liver primordia
43
What happens to the L. Vitelline and umbilical veins?
Channeled toward r. Side w/in liver with proximal portion disappearing
44
What will the r. Vitelline v. Form? And that will eventually become?
Right hepatocardiac channel
Eventually becomes terminal part of the IVC
45
What is the only vein that carries placental blood to liver?
Left umbical vein
46
What will the Left Umbilical V. Connect w/?
Forming what?
Will connect w/ the Right Hepatocardiac channel
Ductus venosus
47
What is the funciton of the ductus venosus?
What maintains its patency during fetal life?
Allows most blood to bypass sinusoids plexus of liver
Prostaglandins
48
What will the happen to the L. Umbilical V. And Ductus Venosus after birth?
Both disappear, leave remnants
L. Umbilical v. —> Ligamentum Teres Hepatis
Ductus Venosus —> Ligamentous Venosum
49
What will the anterior and posterior cardinal v. Join to form?
Form common cardinal V.
50
What do the L. And R. Anterior cardinal veins drain blood from?
Drain most of blood from head and neck
51
What will the anastomosis b/w
Right and Left Cardinal Vs. form?
L. Brachiocephalic V.
52
What will remnants of the L. Cardinal V. Form?
Coronary sinus (along w/ left sinus horn)
53
What will the RIght Common Cardinal v. Form? (Common = anterior & post)
Superior Vena Cava
54
What can happen is there is abnormal development of the ANteiror Cardinal v.?
Can lead to SVC draining into heart via the coronary sinus
55
What do the posterior cardinal veins connect to?
Parallel sets of vins called the Subcardinal and Supracardinal veins
56
What will the Subcardinal veins form?
Form veins primarily associated w/ kidney and gonads and contributors to formation of abdominal IVC
57
What will the Supracardinal veins form?
Portions of IVC and Azygos system and veins draining BODY WALL
58
How does O2 rich blood bypass the liver? To go to where?
Bypass via ductus Venosum
To get to IVC and RA
59
Where will most blood from IVC go thru?
Thru foramen ovale to get to LA
60
Where will a small portion of blood entering the IVC and most blood entering thru SVC go to?
To RV
61
What percentage o blood flow in the developing fetus goes to lungs?
10%
62
What receive blood from the asc. Aorta in the developing fetus? What is the O2 content of this blood?
To arteries of heart, head, neck and UEs
-contain highest level of oxygen content
63
What is the relative blood O2 levels present in blood from the RV?
Medium oxygen content
| Will go to lung or thru ductus arteriosus
64
What is the relative blood O2 levels present in blood from the LEs, portal vein, SVC?
Poor oxygen content
65
What happens after birth that affects ductus arteriosus?
Changes in Blood O2 tension
- drop in prostaglandin
- increase in endothelin (a GF) release from newborn lungs
-stimulates smooth muscle contraction of ductus arteriosus
66
How long does it take for the ductus arteriosus to close?
W/in 10-15 hours of birth
67
What happens if there is a Patent ductus arteriosus (8/10,000)?
1/3-1/2 of blood will enter pulmonary a. And will be circulated thru lungs 2-3 times (increases pulmonary resistance) for every one time it enters systemic circulation
=increased workload for LV = LV hypertrophy
-increased pulm. Rest. = pulmonary congestion = congestive Heart failure
68
With a Patent Ductus arteriosus what can you hear?
Can hear a blowing type of murmur
69
What increases the risk of a patent ductus arteriosus?
Maternal rubella infection during early pregnancy
70
What is the tx for a patent ductus arteriosus?
Prostaglandin inhibitors
Or
Surgery
71
What is a Coarctation of the Aorta?
Aortic lumen below the origin of the L. Subcl. A. Is NARROWED due to abnormal thickening of aortic wall
72
What syndrome is Coarctation of the aorta more common in?
More frequent in Turner’s syndrome
73
What are the 2 types of Aortic Coarctation seen?
Which one is not as dangerous ?
1. Post-ductal -not bad
| 2. Pre-ductal - severe
74
What is a Post-ductal Aortic Coarctation?
Narrowing that occurs AFTER the ductus arteriosus
- allows for collateral circulation to be established thru intercostal arteries and internal thoracic as.
75
What is a Pre-Ductal Aorta Coarctation?
Narrowing that occurs BEFORE ductus arteriosus
- collateral circulation is not well developed
- little to no blood to LEs unless ductus arteriosus remains open (and even then it is O2 poor blood from RV)
76
What causes an ABnormal origin of the R. Subclavian A.?
Only formed by 7th intersegmental and distal portion of R. Dorsal aorta
-the RIght AA 4 and proximal part of R. Dorsal aorta are gone
77
What are the symptoms of an Abnormal R. Subclavian?
May caus difficulting in swallowing and resp. (Dysphagia and dyspnea)
Due to the R. Dorsal aorta crossing esophagus to reach R. UE
78
What is a double aortic arch?
Sxs?
Vascular ring surrounding trachea and esophagus
- Esophageal dysfunction and strangulation of trachea
79
What causes a Right Aortic Arch?
L. AA 4 and L. Dorsal aorta are obliterated and replaced by vessels on right
80
What are the sxs of a Right Aortic Arch?
‣ Complains of dysphagia and dyspnea if left subclavian a. Passes behind esophagus and Ligamentous Arteriosum passes in front of trachea to reach right side
81
What is an Interrupted Aortic Arch caused by?
What will remain open?
L. And R. AA 4 are gone and proximal R. Dorsal aorta
(L. AA 4 formed aortic arch)
-but ductus arteriosus remains open so descending aorta and subclavian as. Are supplied w/ o2 poor blood
82
What will the aortic trunk supply in “interrupted aortic arch syndrome”?
Supplies 2 common carotid arteries
83
What syndrome in Interrupted Aortic Arch seen w/?
DiGeorge Syndrome
