Presentation on theme: "Cardiac embryology Karina & Allison. What we are going to cover… 1.Cardiac embryology 2.Septal formation: atrial, ventricular and arterial outflow 3.Heart."— Presentation transcript:
Cardiac embryology Karina & Allison
What we are going to cover… 1.Cardiac embryology 2.Septal formation: atrial, ventricular and arterial outflow 3.Heart defects 4.Timeline of cardiac development
What type of folding moves the brain, mouth and heart into the adult position? And when does this happen? Longitudinal folding. Day 19. Green line = position of the heart
What is this called? And what is its clinical significance? Transverse pericardial sinus Sits between arterial outflow & venous input Significance: clamp off arterial flow during surgery.
Dilations appear in the heart tube. Name them…
Atria Sinus Venosus Ventricle Bulbus Cordis Truncus Arteriosus Smooth wall of right atria Rough wall of both atria Ventricles Mainly outflow of ventricles Initial part of aorta & pulmonary trunk Aortic sac Left Horn Of Sinus Right Horn Of sinus
And then what happens? LA RA LV Outflow Coronary sinus Vena Cavae Aorta RA RV Outflow Pulm Trunk Pulmonary veins grow out of the left atrial wall and branch. The proximal parts get absorbed into the atrial wall = smooth part Septa form and divide chambers and outflow tract to create the left right sides of the heart
Shunting takes place to avoid the developing lungs. Which direction does this happen in? R L shunting LA RA LV Outflow Coronary sinus Vena Cavae Aorta RA RV Outflow Pulm Trunk
What is this called? Dextrocardia BC V A SV TA Normal Dextrocardia
Atrial Septum: Days 24-35
Atrial Septum Septum primum Foramen primum Septum secundum Foramen ovale Foramen secundum RA LA Valve of Foramen ovale Endocardial cushion
What is the function of the foramen ovale in the fetus? Lungs are fluid filled with high pulmonary resistance. Want to avoid them Therefore blood is shunted through the foramen ovale from R L RA LA The septum primum is relatively floppy – it acts as a valve cusp The septum secundum is muscular and stiff
Sometimes fusion of foramen ovale does not occur. What problems could this cause in later life? Valsava maneuver can briefly increase right sided pressure over left This opens the foramen ovale Can result in emboli passing from right atria to left atria Increases possibility of TIA and stroke.
Ventricular Septum. Day 35-42. What three things come together to form the ventricular septum? Two membranous ridges grow down Muscular septum Endocardial cushion Which of these three parts is most likely to go wrong? Muscle, membrane and endocardial cushion Membranous part
Common ventricular outflow septum. Day 35. APAP A P PAPA Septum forms in truncus arteriosus and bulbus cordis Septum spirals through ____ o creating the aorta and the pulmonary trunk What are the ridges derived from? Neural crest mesenchyme 180
Name all the defects.. Defects Truncus arteriosus Ventricular septal Tetraology of fallot Atrial septal Transposition the great vessels Critical pulmonary stenosis Patent ductus arteriosus Which ones are cyanotic?
What is this defect? Patent ductus arteriosus
Truncus arteriosus. What are the two types? Failure of equal divisionFailure of bulbar ridge formation
What is this defect? Transposition of great vessels – 2 isolated circulations What other defect can be good to have in this condition to help compensate? Patent ductus arteriosus
Multiple cardiac defects can occur together in the tetraology of fallot. What are the 4 components? 1.VSD 2.Overriding aorta 3.RV hypertropy 4.Pulmonary stenosis The heart has been vorped…