E1 Development Of The Heart Flashcards
List the 4 basic stages of heart development
- Cardiac Crescent
- Heart Tube
- Pre-septated looped heart
- Four chambered heart
Heart development begins during week ____
3
Progenitor heart cells migrate through the primitive streak into the _____
Splanchnic layer of lateral plate mesoderm
1st sign of heart formation -> a solid horseshoe-shaped cluster of cells known as _____
Primary Heart Field (PHF)
Once cells establish the PHF, they are induced by underlying _____ to form cardiac myoblasts and _____ and ____ by the process of ______
Endoderm
Blood islands
Vessels
Vasculogenesis
Process of blood vessels arising from blood islands
Vasculogenesis
Process of blood vessels sprouting from existing vessels
Angiogenesis
Blood islands will unite and form horseshoe-shaped endothelial lined tube known as _____ tubes surrounded by myoblasts within the ____ region.
Other blood islands appear which will form the pair of longitudinal _____
Endocardial
Cardiogenic
Dorsal aortae
Lateral body folding creates the _____ (developing heart)
Primordial Heart Tube
______ folding is what repositions the developing heart and pericardial cavities
Cranial-caudal (Sagittal)
Initially, heart tube is attached to dorsal side of pericardial cavity via _____, but the middle section of this structure will disappear and create the ____. At this time the heart tube consists of three layers:
Dorsal Mesocardium
Transverse Pericardial Sinus
- Endocardium
- Myocardium
- Epicardium (Visceral Pericardium)
List the steps of heart development
- Establishing/patterning of primary heart field (PHF)
- Heart tube formation/positioning
- Cardiac Loop formation
- Sinus venosus development
- Partitioning of heart
R/L horns of Sinus Venosus develop into
L horn: Coronary sinus
R horn: Sinus Venarum (smooth-walled portion of R atrium)
Primordial atrium develops into
R/L auricles and portions of atria
Primordial Ventricle develops into
L Ventricle
Conus Cordis (part of Bulbus Cordis) develops into
Outflow tract of ventricles; caudal portion of bulbous cordis forms R Ventricle
Truncus Arteriosus forms
Pulmonary Trunk and Aorta
Tubular heart undergoes _____ looping to form U-shaped loop that results in heart with apex pointing to the ____.
Right-handed
Left
Sinus venosus receives venous blood from 3 paired veins:
- Vitelline vv
- Umbilical vv
- Common Cardinal vv
With the obliteration of the L umbilical and L vitelline (due to blood flow shift to the right side), left sinus horn becomes:
Oblique veins of the left atrium
Coronary Sinus
Right sinus horn becomes incorporated into the ____ to form the ____ (smooth-walled part). Its entrance is the _____
R Atrium
Sinus Venarum
Sinuatrial Orifice
Septa formation happens in two ways:
- Endocardial Cushions
2. Merging two expanding portions of the wall
Near the end of week four, _____ form on each side plus one at the dorsal and ventral walls of AV canal
4 AV endocardial cushions
Fusion of the endocardial cushions results in complete division of the _____ into a ___ and ____ portion
AV canal
Left
Right
Around end of week 4, a crest of tissue known as ____ grows from the roof of the common atrium. It will extend toward the endocardial cushions in the AV canal with an opening below them known as ____
Septum Primum
Ostium Primum
As holes in the septum primum coalesce to form the ____, a thicker ____ develops from the roof of the primordial atrium slightly to the right of septum primum
Ostium Secundum
Septum Secundum
Septum Secundum grows inferiorly and develops an opening known as _____
Foramen Ovale
After birth, the pressure in the left atrium increases as the blood returns from the lungs, septum primum is pressed against the septum secundum and adheres to it, permanently closing the ____ and forming the _____
Foramen ovale
Fossa ovalis
End of week 4, primitive ventricles begin to expand, medial walls will merge to form _____ with _____ located about it.
Muscular Interventricular Septum
Interventricular Foramen
Outgrowth of the inferior endocardial cushion closes the Interventricular foramen. Complete closure forms the _____ part of the Interventricular septum
Membranous
During week 5, ____ migrate into truncus arteriorsus and bulbous cordis to form _____, which will undergo a 180 degree spiraling which results in formation of a spiral ____ when they fuse.
Neural crest cells
Truncal and Bulbar ridges
Aorticopulmonary septum
Most common congenital heart defect (25%). Failure of IV septum to completely form. Can involve membranous or muscular portion of septum.
Ventricular Septal Defect (VSD)
Primordial pulmonary v and branches develop into
Smooth-walled portion of left atrium
Aortic sac develops into
Ascending aorta
Congenital heart defect present at birth. Usually four different types of defects (VSD, Pulmonary Stenosis, R Ventricular Hypertrophy, Overriding Aorta).
Tetralogy of Fallot
