Cardiovascular - Session 3 Flashcards
What is the name of the process in which the heart is separated?
Septation
Where do the endocardial cushions form?
Extra point - what is their purpose?
In the atrioventricular canal. They join to separate left and right.
What does the septum primum do?
Grows towards the endocardial cushions.
What are the names of the openings in the septum primum?
Ostium primum before the septum primum fuses.
Ostium secundum appears as the ostium primum fuses.
What is the name of the second septum that forms in atrial septation?
Septum secundum.
What is the name of the hole in the septum secundum?
Foramen ovale.
The ostium secundum and foramen ovale do not line up, so how does blood flow through them?
The pressure is higher on the right so this allows the blood to flow through the holes.
What are the components of the ventricular septum?
Extra point - what is the relative quantities of them in its formation?
Muscular and membranous.
Muscular - most of it.
Membranous - connective tissue to fill the gap.
What is the name of the small gap left between the ventricular septum and endocardial tissue?
Primary interventricular foramen.
It is fused by the membranous ventricular septum which is made of connective tissue.
What is used for septation of the outflow tract?
The conotruncal septum
Where do endocardial cushions appear in septation of the outflow tract and what is special about their formation?
In the Truncus arteriosus. They grow towards and twist around one another
What causes the for ament ovale and dictus arteriosus to close?
First breath by the baby which increases the pressure in the left atrium.
What causes the ductus venosus to close?
Placental support is removed.
What is the fate of the foramen ovale after birth?
It is the fossa ovalis (thumb print in right atrium wall)
What is the fate of the ductus arteriosus after birth?
It becomes the ligamentum arteriosum.
