Embryology of the CVS 2 Flashcards
what are the 2 ways in which blood vessels develop?
vasculogenesis
angiogenesis
what is vasculogenesis?
it is the process of blood vessel formation occurring a de novo production of endothelial cells
what is vasculogenesis defined as?
the new formation of a primitive vascular network
what is angiogenesis defined as?
the growth of new vessels from pre-existing blood vessles
what can angiogenesis basically be described as ?
the development o new blood vessels
what is the aortic sac?
it is a dilated structure in the embryo
what is the aortic sac lined by?
endothelial cells
where is the aortic sac located?
just above the truncus arteriosus
describe the aortic sac?
it is the primordial vascular channel from which the aortic arches arise
what arises from the aortic sac?
the aortic arches
what are the parts to each primitive aorta?
ventral part - ventral aorta
dorsal part - dorsal aorta
what occurs after the fusion of the 2 endocardial tubes?
the 2 ventral aorta partially fuse to form the aortic sac
what is an extension of the truncus arteriosus of the primordial heart tube?
the formation of the aortic sac
when do the pharyngeal arch arteries develop?
during the 4th and 5th week
where are the pharyngeal arch arteries located?
they are ventral to the dorsal aorta and arise from the aortic sac
what are the pharyngeal arteries?
they are a serious of 6 paired embryological vascular structures
what do the pharyngeal arteries give rise to?
they give rise to the great arteries of the neck and head
what are the 3 branches of the aortic branches?
the brachiocephalic trunk
the left common carotid artery
the left subclavian artery
what are pharyngeal arteries called when they communicate with aortic branches?
aortic arches
what is the dorsal aorta?
it is a large embryonic artery
how is the dorsal aorta formed?
it is formed by the fusion of the caudal parts of the paired primordial aorta
what does the dorsal aorta become?
it becomes the descending aorta and median sacral artery
what is an aberrant subclavian artery?
it is a rare anatomical variant of the origin of the right or left subclavian artery
what is the most common congenital vascular anomaly of the aortic arch?
the aberrant subclavian artery - this particular abnormality
what is a double aortic arch?
it is a relatively rare congenital cardiovascular malformation
describe a double aortic arch
it is an anomaly of the aortic arch in which 2 aortic arches form a complete vascular ring that can compress the trachea and/or oesophagus
what is patent ductus arteriosus?
it is a condition wherein the ductus arteriosus fails to close after birth
what is the ductus arteriosus?
it is a foetal blood vessel that closes soon after birth
what is coarctation of the aorta?
it is a congenital condition
describe coarctation of the aorta
narrowing of the aorta
where does coarctation of the aorta usually occur?
it usually occurs in the area where the ductus arteriosus inserts
what does coarctation of the aorta affect?
this narrowing of the aorta affects blood flow where the arteries branch out to carry blood along separate vessels to the upper and lower parts of the body
what does coarctation of the aorta cause?
it can cause high blood pressure or heart damage
what does placental circulation allow?
it allows the umbilical arteries to carry deoxygenated and nutrient-depleted foetal blood from the foetus to the villous core foetal vessels
what does vitelline circulation refer to?
it refers to the system of blood flowing from the embryo to the yolk sac and back again
where is the yolk sac situated?
it is situated on the ventral aspect of the embryo
what is the yolk sac lined by?
it is lined by endoderm, outside of which is a layer of mesoderm
describe vitelline circulation
it is the circulation of blood and nutrients between the developing embryo and the yolk sac by way of the vitelline arteries and veins
what are vitelline veins?
they are veins which drain blood from the yolk sac
what are vitelline arteries?
they are arteries that play an important role in the vitelline circulation of blood to and from the yolk sac of foetus
what arteries are a branch of the dorsal aorta?
vitelline arteries
what are anterior cardinal veins also known as?
pre cardinal veins
what do anterior cardinal veins contribute to?
the formation of the superior vena cava from the internal jugular veins and common cardinal veins
what is the left umbilical vein?
it is the vein that returns the blood from the placenta to the foetus
what vein transverses the umbilical cord?
the left umbilical vein
what vein enters the foetal body at the umbilicus and then passes into the liver?
the left umbilicus cord
what vein is then joined by the portal vein?
the left umbilical vein
how many umbilical arteries are there
2
what do the umbilical arteries surround
the urinary bladder
what is the role of the umbilical arteries
they carry all the deoxygenated blood out of the foetus through the umbilical cord
where are the umbilical arteries present
they are present together with one umbilical vein in the umbilical cord
where do the umbilical arteries arise from?
the hypogastric arteries of the mammalian foetus
which arteries carry deoxygenated blood from the foetus?
the umbilical arteries
where do the umbilical arteries pass through?
they pass through the umbilical cord to the placenta to which they carry the deoxygenated blood from the foetus
what are the arterial counterpart to the vitelline veins?
the vitelline arteries
which arteries supply the yolk sac?
the embryo vitelline arteries
what artery supplies the foregut?
the celiac artery
which artery supplies the midgut?
the superior mesenteric artery
which artery supplies the hindgut?
the inferior mesenteric artery
what is the role of the umbilical arteries?
they supply deoxygenated blood from the foetus to the placenta
what is the umbilical vein?
it is a vein present during foetal development that carries oxygenated blood from the placenta into the growing foetus
where do the umbilical veins originate from?
chorionic villi of placenta
what is the role of the umbilical veins?
they carry oxygenated blood to the embryo
where do vitelline veins carry blood from?
from the yolk sac to the sinus venosus
what is the portal vein?
it is a vein conveying blood to the liver from the spleen, stomach, pancreas and intestine
what are liver sinusoids?
they are a type of sinusoidal blood vessel that serves as a location for mixing of the oxygen-rich blood from the hepatic artery and the nutrient-rich blood from the portal vein
what is the superior mesenteric vein?
it is a blood vessel that drains blood from the small intestine
where does the superior mesenteric vein terminate?
it terminates behind the neck of the pancreas
where does the superior mesenteric vein combine with the splenic vein to form the hepatic portal vein?
where the superior mesenteric vein terminates, which is behind the neck of the pancreas
what is the ductus venosus?
it is a vein that passes through the liver and connects the left umbilical vein with the inferior vena cava of the foetus
after birth what does the ductus venosus persist as?
it persists as the ligament venosum of the liver, as the circulation that occurs from this vein is lost
what is the duodenum?
it is the first part of the small intestine immediately beyond the stomach, leading to the jejunum
what is the role of the cardinal veins?
they carry the blood from the head and the lower body into the heart
state 4 venous system abnormalities
double IVC
absence of IVC
left SVC
double SVC
what is meant by a double IVC
it is duplication of inferior vena cava
- it is a vein abnormality
congenital condition
2 inferior vena caves instead of one
what is the absence of the inferior vena cava associated with?
it is associated with idiopathic deep vein thrombosis
what is the most common variation of the thoracic venous system?
a persistent left superior vena cava
what is a persistent left superior vena cava?
it is an embryologic remnant that results from a failure to involute
when does the lymphatic system develop?
at the end of week 6 around main veins
when do the 6 primary lymph sacs develop?
at the end of the embryonic period
what do lymphatic vessels develop from?
lymph sacs
what do lymph sacs give rise from?
developing veins and derived from mesoderm
what are the first lymph sacs to appear?
the paired jugular lymph sacs
where do the paired jugular lymph sacs appear?
at the junction of the internal jugular and subclavian veins
what is the ductus venosus?
it is a vein passing through the liver
what does the ductus venosus connect?
it connects the left umbilical vein with the inferior vena cava of the foetus
what does the ductus venosus persist as after birth when this veins circulatory function is lost?
it persists as the ligamentum venosum
what is the ovale foramen?
it is an opening/hole in the septum between the atria of the heart
when is the ovale foramen present?
it is normally only present in the foetus
what does the foramen ovale allow?
it allows blood to enter the left atrium from the right atrium
what does the foramen ovale allow?
this hole allows blood to bypass the lungs
what is the ductus arteriosus?
it is a blood vessel
what does the ductus arteriosus connect?
it connects the main pulmonary artery to the proximal descending aorta
what does the ductus arteriosus allow?
it allows most of the blood from the right ventricle to bypass the foetus’ fluid-filled non-functioning lungs
