Download Development of Arterial and Venous System

Development of Arterial and Venous System
Learning Objectives
By the end of this lecture, the students should be able to understand:
• The relation of Pharyngeal Arches and Aortic Arches
• The fate and formation of aortic arches
• Formation of Brachiocephalic Trunk, Common Carotid and left Subclavian
arteries
• The Veins of Embryo
• Development and Fate of Umbilical, Vitelline and Cardinal Veins
Arterio-Venous System
•
Origin of Arterial System
• Aortic arches
• Right and Left Dorsal Aortae
Aortic Arches
• During the development of Head and Neck, each pharyngeal arch receives
its own artery
• Six pairs of arteries called aortic arches course through the pharyngeal
arches
• Aortic arches arise from the aortic sac, the most distal part of the truncus
arteriosus
• Aortic arches are embedded in mesenchyme of the pharyngeal arches and
terminate in the right and left Dorsal Aortae
Aortic Arches
• The pharyngeal arches and their vessels appear in a cranial to caudal
sequence
• Aortic arches are numbered I, II, III, IV, and VI
• The fifth arch either never forms or forms incompletely and then regresses
• During further development, this arterial pattern becomes modified, and
some vessels regress completely
First and Second Arch
• By day 27, most of the first aortic arch has disappeared except a small
portion persists to form the maxillary artery
• The second aortic arch soon disappears except a small portion giving rise
to hyoid and stapedial arteries
Third Aortic Arch
• The third aortic arch forms the common carotid artery and the first part of
the internal carotid artery
• The remainder of the internal carotid is formed by the cranial portion of the
dorsal aorta
• The external carotid artery is a sprout of the third aortic arch
Forth Aortic Arch
• The fourth aortic arch persists on both sides, but its ultimate fate is different
on the right and left sides
• On the left, it forms part of the arch of the aorta, between the left common
carotid and the left subclavian arteries
• On the right, it forms the most proximal segment of the right subclavian
artery
•
The distal part of right subclavian artery is formed by a portion of the right
dorsal aorta and the seventh intersegmental artery.
Fifth Aortic Arch
• The fifth aortic arch either never forms or forms incompletely and then
regresses.
Sixth Aortic Arch
• The sixth aortic arch is also known as the pulmonary arch
• On the right side, the proximal part becomes the proximal segment of the
right pulmonary artery
• The distal portion of Sixth arch on the right side loses its connection with the
dorsal aorta and disappears
•
On the left, the distal part persists during intrauterine life as the ductus
arteriosus.
Fate of Aortic Arches
Embryologic
Structure
Adult Equivalent
First aortic arch
maxillary artery
contribution to external carotid artery
Second aortic
arch
persists dorsally as stapedial artery
Third aortic arch
proximal portions form portion of Right and Left
common carotid artery
distal portions form Right and Left internal carotid
artery
Fourth aortic arch
left arch (with aortic sac) forms ascending aorta and
arch
right arch contributes to right subclavian artery
Fifth aortic arch
does not persist
Sixth aortic arch
proximal left arch - left pulmonary artery
distal left arch - ligamentum arteriosum
proximal right arch - right pulmonary artery
distal right arch - does not persist
The Dorsal Aorta
• The dorsal aorta between the entrance of the third and fourth arches, known
as the carotid duct, is obliterated
• The right dorsal aorta disappears between the origin of the seventh
intersegmental artery and the junction with the left dorsal aorta.
Fate of Dorsal Aorta
Embryologic
Structure
Posterolateral
Branches
Adult Equivalent
Arteries to Upper and Lower Extremity
Intercostal arteries
Lumber arteries
Lateral Sacral arteries
Lateral Branches
Renal, Supra renal and Gonadal arteries
Ventral Branches
Vitelline arteries
Celiac, Superior mesentric and Inferior mesentric arteries
Umbilical arteries
Internal iliac arteries(portion of)
Superior vesical arteries
Medial umbilical ligaments
Vitelline and Umbilical arteries
• Arteries supplying yolk sac (number of paired arteries) – vitelline arteries
• They develop in vascular supply of gut – celiac, superior mesenteric, and
inferior mesenteric artery
• Umbilical arteries – paired branches of dorsal aorta – to placenta (allantois)
in embryonic stalk or later in umbilical cord
• It persist as internal iliac and superior vesical arteries (medial umbilical
ligaments)
Development of Venous System
Three Pairs of Veins are present in embryo:
• Vitelline veins
• Umbilical veins
• Common cardinals veins
The Veins of the Embryo
• Common Cardinal Veins collect the deoxygenated blood from the body wall
• Each common cardinal vein consists of
– Anterior common cardinal vein
– posterior common cardinal vein
• Umbilical Veins carrying the oxygenated blood from the Placenta
•
Vitelline veins bring the deoxygenated blood from the Yolk Sac & gut
The Veins of the Embryo
The Veins of the Embryo
Umbilical Veins
• During the early development of embryo, there are two umbilical veins right
and left
• The umbilical veins bring the nutrient- and oxygen-rich blood from the
placental villi via the umbilical cord to the embryo
• Left umbilical vein persist through out fetal life and degenerate after the
birth of baby
• Right umbilical vein becomes obliterated during the 2nd month
Fate of Umbilical Veins
• Initially pass along liver, then enter liver participating on sinusoids
formation
• Proximal part of both and right left umbilical vein disappear
• Peripheral part of left umbilical vein - in umbilical cord
• Anastomosis with vena cava (right hepatocardial duct) – ductus venosus
• After birth- ligamentum teres hepatis (from artery) and ligamentum venosum
(from duct)
Ductus Venosus
• A large venous shunt, the Ductus Venosus
develops within the liver and connects the
umbilical vein with inferior vena cava
• The ductus venosus forms a bypass through
the liver so that most of the blood directly
transported from the placenta to the heart
without passing through the capillaries of liver
• Left umbilical vein anastomoses with the ductus venosus.
Vitelline Veins
• Vitelline veins form plexus surrounding duodenum – pass septum
transversum - sinusoids in liver
• The vitelline veins drain into sinus venosus
• Reduction of left sinus horn – blood flow enter right side of heart – right
hepatocardiac channel – hepatocardiac portion of the inferior vena cava
Fate of Vitelline Veins
• Network around duodenum – portal vein
• Left vitelline vein except for hepatic part disappears
• Right viteline vein – superior mesenteric vein
Formation of Hepatic & Portal Veins
• The hepatic veins form from the remains of the Right vitelline vein in the
region of developing liver
• The Portal vein develops from an anastomostic network of vitelline veins
around the
duodenum
Common Cardinal Veins
• There are two common cardinal veins right & left
• Each common cardinal vein divided into Anterior cardinal vein bring the
deoxygenated blood from cranial part of body & Posterior cardinal vein
collects the blood from the caudal part of body
• Ultimately the two common cardinal veins drain into respective horn of
sinus venosus
Cardinal Veins
Cardinal Veins
• During the eight week of development the anterior cardinal veins are
connected to each other by means of an oblique anastomosing channel, that
shunts the blood from left to right anterior cardinal vein
• This anastomosing channel become the left Brachiocephalic Vein when the
caudal part of left anterior cardinal vein degenerate.
Subcardinal Veins
• The subcardinal and supracardinal veins are gradually replace and
supplement the posterior cardinal vein
• The subcardinal vein lies infront of gut
• The subcardinal veins appear first and form the left renal vein, the
suprarenal vein, the gonadal (testicular or ovarian) veins and a segment
of inferior vena cava.
Supracardinal Veins
• The supracardinal veins are disrupted in the region of kidneys behind the gut
• Cranial to this region, they united by an anastomosis that form the Azygos
and the hepatic veins
• Caudal to the kidneys the left suprarenal vein degenerates but the Right
supracardinal become the part of inferior vena cava
• The IVC is formed due to shunt of the blood from left right site of caudal
part of embryo
Superior Vena Cava
• The superior vena cava is formed from the Right anterior cardinal vein and
right common cardinal vein
• Superior Vena Cava receives blood from two brachiocephalic Veins
• Each Brachiocephalic Vein is formed by union of internal jugular vein and
subclavian vein
• The adult derivatives of the posterior cardinal veins are the root of azygos
veins and common iliac veins
Development of Inferior Vena Cava
The development of inferior vena cava consists four segments;
• Hepatic Segment, derived from the hepatic vein (proximal part of the right
vitelline vein) and hepatic sinusoids
• Prerenal segment is derived from the right subcardinal vein
• Renal Segment is derived from the subcardinal- supracardinal anastomosis
• Postrenal Segment is from right supracardinal vein
Embryologic Structure
Adult Equivalent
Left anterior cardinal vein
disappears proximally
distal portion contributes to Left superior intercostal vein
anastomoses with Right anterior cardinal vein distally to form Left brachiocephalic vein
Left common cardinal vein
oblique vein of left atrium
Left posterior cardinal vein
disappears
Left horn of sinus venosus
coronary sinus
Right anterior cardinal vein
superior vena cava
Right common cardinal vein
superior vena cava
Right posterior cardinal vein
azygous vein
Left umbilical vein
ligamentum teres distally
degenerates proximally
portion within septum transversum contributes to hepatic portal system
Right umbilical vein
degenerates proximally and distally
portion within septum transversum contributes to hepatic portal system
Left vitelline vein
fuses with right vitelline vein to form portal vein
Right vitelline vein
fuses with left vitelline vein to form portal vein