Development of the Heart Flashcards
When does the cardiovascular system develop
It is the first system to functionally develop
Happens btw 1st and 8th week
Mainly develops during middle of 3rd week
When does blood start to circulate
Beginning of the 4th week
How does the heart get to ventral surface of embryo
Head fold
Brings heart and pericardial cavity ventral to foregut
When does heart begin to beat
22-23 days
Truncus Arteriosus
Outflow of developing heart
Continuous with aortic sac
Bulbus Cordis
Outflow of developing heart
Proximal to truncus arteriosus
Sinus Venosus
Receives veonous blood flow from chorion, yoik sac, and embryo
Will develop right and left horns
Bulboventricular Loop
Bulbus cordis and primitive ventricle develop faster than other regions so the heart bends upon itself
Bends down and to the right
Sets up inflow and outflow
Inflow
Posterior - Back
Outflow
Anterior - Front
Blood Flow through Primordial Heart - Caudally to Cranially
- Sinus Venosus
- Primordial Atria
- Atrioventricular Canal
- Primordial Ventricle
- Bulbus Cordis
- Truncus Arteriosus
- Aortic Sac
- Aortic Arches
Partitioning of heart…when?
Begins middle of 4th week and is done by end of 5th
Development of semilunar valves
develop from three swellings of subendocardial tissue
position of the cusps after rotation is normal anatomical way of naming
Pulmonary Semilunar Valves
Right, Left and Anterior Cusps
Aortic Semilunar Valve
Right, Left and Posterior Cusps
Development of AV Valves
Proliferation of endocardial cushions around AV canals
Goal of Septum Primum
Close the foramen primum
Grows inferiorly to atrioventricular juntion
Goals of Septum Secundum
Overlap the foramen secundum
Overlapping forms flap like valve - foramen ovale
Formation of Right Atrium
Sinus Venosus develops left and right lateral horns
Right - becoems sinus venarum (smooth part of RA)
Left - becomes coronary sinus
Crista Terminalis
Junction between the right horn of sinus venosus (smooth) and the right side of primitive atrium (pectiante muscle)
Formation of Left Atrium
All smooth - more and more blood coming in, pulmonary vein gets bigger and is incorporated into LA
Smooth because of original pulmonary vein - used to be a blood vessel
Primitive gets pushed anteriorly and becomes the auricle (only rough place with pectinate)
Total Anomalous Pulmonary Vein
Congenital Defect
Primordial pulmonary vein gets incorporated into right side of developing interatrial septum therefore draining into right atrium instead of the left
Muscular Portion of IV Septum
Grows up (cranially) to meet the membranous portion Divides the primitive ventricle into right and left side
Membranous Portion of IV Septum
Derived from tissue off the right side of endocardial cushion and aorticopulmonary septum
