Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

46 Cards in this Set

  • Front
  • Back
What give rise to the precardiogenic mesoderm?
Anterior lateral plate mesoderm gives rise to precardiogenic mesoderm.
What is precardiac mesoderm? Where is it? Describe it.
It constitutes a horse-shoe-shapes region of the mesoderm extending back on either side along the foregut. An inductive influence from the neighboring endoderm stimulates formation of the heart.
When is a cardiogenic plate visible? Where is it located?
As the mesoderm spits into splanchnic mesoderm and somatic layers a cardiogenic plate is recognizable in the splanchnic mesoderm rostral to the oropharyngeal membrane.
What forms the valves of the heart?
Cardiac jelly.
What fuses to form the primitive tube of the heart?
What forms the right ventricle?
The truncus and conus (bulbus cordis)
What forms from the conus?
The exit of the right ventricle, conus arteriosus.
What foms the left ventricle?
The primitive ventricle.
What forms the common atria?
Primitive atria.
What forms from the sinus venosus?
The right atrium.
Give the order of the structures in the primitive heart tube from most superior to inferior.
Aortic sac, truncus, conus, primitive ventricle, primitive atria, sinus venosus.
What comes to lie dorsally from the bulbus cordis during looping?
The atrium and sinus venosus.
Formation of the pericardial cavity:
When does the ventral mesentary of the heart disappear?
Very early.
How does the transverse sinus form?
The dorsal mesocardium persists during the formation of the pericardial cavity and as the heart begins to bend the central part degenerates and gives rise to the transverse sinus.
Where does the dorsal mesocardium persist?
At the cranial and caudal ends of the tube.
What forms the myocardial primordium? (formation of heart wall)
Splanchnic mesoderm.
What forms endocardial primordium? (formation of heart wall)
Between the myocardial primordium and endoderm, isolated mesodermal vesicles appear and fuse to form the endocardial primordium.
What separates the myoepicardium from the endocardium and gives rise to subendocardial tissue?
Cardiac jelly
How does the atrium become partially separated from the ventricle during the partitioning of the heart?
The atrium becomes partially separated from the ventricle by the formation of thickened atrioventricular cushions.
Describe the development of AV cushions.
Thickenings of subendocardial tissue called cushions develop in the region of the AV canals. These cushions then grow towards each other and fuse.
Describe the motion of the AV canal during development.
The inferior and superior endocardial cushions push the canal towards the right ventricle and away from the left ventricle. It then seperates at 42 days via a septum intermedium into two canals (right and left AV canals).
Describe the 5 things that happens in later partitioning of the heart in order.
1) separation of atria from the ventricles
2) partition of the atria
3) reposition of the sinus venosus
4) Partitioning of the ventricles
5) partitioning of the outflow tract
What does the septum primium form?
The ostitium premium (makes valve of fossa ovale)
What is the origin of the lingum of fossa ovale?
Septum segundum.
What is the significance of the foramen ovale?
The foramen ovale stays open and allows transfer of blood between atrium. This is because blood must be shunted away from the developing lungs untill they are ready to take on the tasks of oxygenating blood.
What happens in the left atrium once the foramen ovale closes?
Left atrium blood pressure increases
The sinus venosus remains a paird structure with right and left horns. What are the 3 veins that supply each horn? (from most external to internal branch)
1) common cardinal vein
2) Umbilical vein
3) vitelline vein.
What happens as the sinoatrial orifice shifts to the right?
The sinus vensosus communicates only with the right atrium.
What happens to the right sinus horn during development?
The right sinus horn becomes enlarged.
What froms the superior vena cava?
The right anterior cardinal vein.
What forms the inferior vena cava?
The right vitelline vein?
What forms from the right umbilical vein?
NOTHING it is obliterated!
What forms the coronary sinus?
The left sinus horn.
What is the sinoatrial orifice flanked by?
2 Valves, the right and left venous valves.
What do the 2 venous valves that flank the sinoatrial orifice form?
Superiorly they meat to form the septum spurium.
Which side ofth heart is the crista terminalis found on?
The right side!
What side of the heart is the coronary sinus found on?
The right side!
What side of the heart is the sinus venarum found?
On the right side!
What first indicates partitioning of the ventricles?
The formation of a muscular ridge (the interventricualr septum) in the floor of the ventricle near the apex.
When do the interventricualr grooves appear?
As the ventricles dialate on both sides of the septum.
When is the IV foramen closed and the septum completed?
The 8th week.
What produces elastic fibers? Why are these fibers so important?
Neural crest derived cells of the outflow tract produce elastic fibers which provide resiliency required of the aorta and other great vessels.
What forms cardiac ganglion and the outflow tract of the heart?
Neural crest
What forms the ligamentim arteriosum?
The ductus arteriousus.
What does the ductus arteriosus connect?
The aorta and the pulmonary arteries.
Describe the flow of fetal blood starting from the umbilicus.
From the umbilicus to the umbilical vein to the liver, through the ductus venosus, up to the right atrium and either to the left atrium or right ventricle. From the right ventricle it can go up to the pulmonary arteries then through the ductus arteriosus to the aorta or to the developing lungs. Blood from the aorta goes down through the body and suppies the kidney, adrenal glands, GI tract and can go back into the liver. However it can also exit back through umbilical arteries to the mother's body.