Heart Development And Fetal Circulation Flashcards
What a re the components of the heart tube
Aortic sac: the ascending aorta and brachiocephalic trunk
Trunchus arteriosus: ascending aorta and pulmonary trunk
Bulbous cordius: right atrium and the outflow tracks
Primitive atrium
Primitive ventricle
Sinus venosus
(Common cardiac vein, umbilical vein, vitelline vein)
What forms the notochord
Cells from the mesoderm
What layer forms the neural tube
The ectoderm
What are the areas of the mesoderm for the heart
paraxial
Intermediate
Lateral (somatic and splanchnic)
What area of the mesoderm would be mostly involved in the formation of the heart tube
The splanchnic
Would form the heart tube and the pericardial cavity
What anchors the heart tube
The dorsal mesocardium
What does the dorsal mesocardium form when it degenerates
Transverse sinus of the heart (drains blood from the veins of the cerebellum and the inferior surface of the brain)
What forms the septum intermedium
The neural crest cells
What are the steps of the septum formation
The septum intermedium would be formed from he neural crest cells
So would the septum primum
Gap between he two would be the ostium primum
Septum primum and the septum intermedium come together
New gap is the ostium secondum (Forman ovale)
Second septum seconding would be formed in he RA
What are the areas of the interventricular septum
The membranous area (most likely to have damage)
The muscular layer
What area of the interventricular septum would be more prone to damage
The membraneous area
What area would form the inflow tracts and what would form what
The right horn
The umbilical vein would degenerate
The Common cardinal vein forms the superior vena cava
The vitelline vein forms the inferior vena cava
What happens to the left horn of the heart
Would degenerate
The sinus venosus would be taken up by the right atrium
Forms the pacemaker
What else does the sinus venosus form
The visceral pericardium around the heart
How are the outflow tracks formed
The bulbous cordis
Neural crest cells (truncal ridge and the bulbar ridge at the bottom)
Come together and give the aortio-pulmonary septum
Would then the rotation, would give the aorta and the pulmonary artery’s
What are the characteristics of fetal circulation
Right side would have more pressure then the left side
No developed lungs
Hypoxic, so would have pulmonary to conserve oxygen
What is the path taken by the oxygenated blood
From the placenta up the umbilical vein
Through the ducteous venosus in the liver
Through to the right atrium
High pressure would force into the left atrium and ventricle
Though the aorta and to the body
Some would go down the ducteous arteriosus (so to the umbilical artery)
Whats the oath of the deoxygenated blood
Gravity would push done to the right ventricle
Up the pulmonary artery
Through the ducteous arteriosus
Down the umbilical artery and then to the placenta
What does the Foreman ovale form
The fossa ovale
What does the ductus venosus shunt form
The ligamentum venosum (liver ligament)
What does the ducteous arteriosus shunt form
Ligamentum arteriosum (connects pulmonary trunk and aorta)
What do the umbilical artery’s form
The medial umbilical ligament
What does the umbilical vein forms
The ligamentum teres
What do the majority of the heart defects stem form
Trisomy 21
What happens in the right to to left shunt
Deoxygenated blood would go to to the left side of the body, would then have he blueing of the limbs (would not be getting enough oxygen)
What Happens in the left to right shunt defect
Systematic system would still get the deoxygenated blood
Would soon have the blood going to the right, the pulmonary system would not be able to handle the high pressure
Would have hypertrophy of the walls
Blood would come back and would soon have a right to left shunt created
What mainly causes the left to right shunt defect
Atrium and Ventricle septum defect
What would mainly cause the right to left shunt defects
Transposition of the great artery’s
The aorta and the pulmonary artery’s would swap sides
What is the tetralogy of the fallout
4 conditions that would be caused from the heat defects
Ventricle septum defects
Hypertrophy
Pulmonary stenosis (valve would not close properly)
Aortic displacement (aorta starts where the septum defect is)
What forms to transverse sinus of the heart
Dorsal mesocardium
What is the oblique sinus
Posterior to the left atrium
Would allow the expansion of the left atrium
At what day does the hear start to beat
Day 22
What cells mainly form the septum’s of the heart
The neural crest cells
