Lecture 2-Development of the Heart-Prof. Dr. dr. Dwi Cahyani R. S., M.Kes., PA(K) (2024)
Page 1: Title and Introduction
Title: Development of the Heart
Author: Dwi Cahyani Ratna Sari
Department: Department of Anatomy, Universitas Gadjah Mada
Motto: Locally Rooted, Globally Respected
Page 2: Heart Development Overview
Earliest Major Organ to Function: The heart is the first organ to function in the embryo.
Function Begins: Starts functioning at the beginning of the fourth week of gestation.
Contraction Initiation: The heart starts to contract by day 22 post-fertilization.
First Indication: Heart development can be observed in embryos at approximately 18-19 days.
Formation Location: The heart anlage forms at the cephalic ends of the embryonic disc and is paired.
Page 3: Developmental Structures
Components Involved in Heart Development:
Myoblasts and angiogenic cell clusters
Neural plate
Intraembryonic splanchnic cavity mesoderm
Primitive endoderm node
Cardiogenic field
Notochord
Page 4: Event Sequence in Heart Formation
Key Events: A visual outline of the steps leading to heart formation (indicated by the images).
Page 5: Formation of the Endocardial Heart Tube
Cardiogenic Area: Splanchnic mesenchymal cells aggregate and align side by side.
Formation:
Two longitudinal strands called cardiogenic cords canalize to form two thin-walled endocardial heart tubes.
These tubes gradually approach and fuse to create a single heart tube.
Page 6: Single Heart Tube
Result: Formation of a single tube that will develop into the heart.
Heart Tube Segmentation: Initial stages of constructing the heart segments.
Page 7: Heart Tube Segments
Constructions of Heart Tube:
The heart tube exhibits minor constrictions.
Segments listed in order from caudal to cranial:
Sinus venosus
Primitive atrium
Primitive ventricle
Bulbus cordis
Truncus arteriosus
Page 8: Heart Tube Looping
Looping Process: Heart develops a C-shape by looping in the craniocaudal axis.
Directional Changes: Cephalic portion bends ventral and caudal, while the caudal atrial portion shifts dorsocranially and to the left.
Page 9: Developmental Changes During Looping
Shaping Process: Heart follows a sequential process of looping, forming a characteristic S-shape.
Positioning: The atria move backward and upward, lying cranially and behind the ventricle.
Page 10: Timeline of Heart Development
Blood Flow Timing: Sequence of heart structure development over days 18 to 35:
Truncus arteriosus and primitive heart tube formation.
Visual mapping of blood vessels at specific days.
Page 11: Heart Morphology Over Time
Days 20 to 28: Details of changes in ventricular structure and heart bending as development continues.
Page 12: Adult Heart Structures Derived from Embryonic Formations
Key Structures: Outline of structures formed from embryonic dilatation:
Truncus arteriosus → Aorta and pulmonary trunk.
Various segments from primitive ventricle and atrium.
Page 13: Septation Process in the Heart
Second Month Development: Heart begins to septate into distinct atria and ventricles, starting around the fourth week.
Completion of Partitioning: Essential completion by the end of the fifth week.
Page 14: Types of Septation
Septa Formation includes:
Atrioventricular canal partitioning
Primitive atrium partitioning
Primitive ventricle partitioning
Truncus arteriosus partitioning
Page 15: Endocardial Cushions
Formation: Dorsal and ventral heart walls form protrusions known as endocardial cushions that fuse, paving the way for the left and right atrioventricular canal.
Page 16: Heart Cross-section (Week 5)
Detailed Anatomy: Cross-section showing developing structures including atrium and outflow tract.
Page 17: Atrioventricular Canal Partitioning
Septation Process: The atrioventricular canal divides into distinct channels providing routes for blood flow.
Page 18: Heart Chamber Separation
Main Divisions: Heart is divided into two halves by three essential septae:
Interatrial septum
Interventricular septum
Aorticopulmonary septum
Page 19: Interatrial Septum Development
Septum Creation: Development of septum primum and septum secundum along right hand side, forming foramen ovale.
Page 20: Partitioning Mechanisms in the Atrium
Septum Formation: Describes the development of septae and foramen in the atrial region at various stages.
Page 21: Interventricular Septum Composition
Two Portions: Describes the membranous and muscular parts of the interventricular septum and their initial structures.
Page 22: Structuring the Interventricular Septum
Development: Fusing of muscular septum portions to form a membranous interventricular septum.
Page 23: Final Structure of the Interventricular Septum
Fusion of Structures: Completion of the interventricular septum through the interaction of various embryonic tissues.
Page 24: Summary of Ventricular Separation
Key Fusions: Identifies the structures that must interconnect to finalize ventricular separation, including the endocardial cushions and the spiral septum.
Page 25: Heart Valves and Outflow Channels
Detailed Anatomy: Identification of the components associated with right and left ventricular outflow channels.
Page 26: Conotruncal Region Partitioning
Formation of Aorticopulmonary Septum: Overview of how neural crest cells influence the conotruncal region for heart development.
Page 27: Septation of Aorta and Pulmonary Trunk
Functional Context: Links between the developing outflow tract of the heart and the establishment of arterial pathways.
Page 28: Aorticopulmonary Septum Development
Separation: Elaborates on the separation of the bulbus cordis into aorta and pulmonary artery.
Page 29: Sinus Venosus Characteristics
Anatomy: Overview of the sinus venosus structure and its connections to the heart.
Page 30: Development of Aortic Arches
Evolution: Lists fates of the different aortic arches and their contributions to adult structures.
Page 31: Aortic Arch Variations
Right vs Left: Differentiates the functional outcomes of the fourth aortic arch on the left and right sides.
Page 32: Pulmonary Arch Development
Finalization of Arteries: Discusses the transformation of the sixth aortic arch into branches that lead to the lungs.
Page 33: Adult Great Arteries
Identification: Lists the major adult arteries derived from embryonic structures post-development.
Page 34: Fetal Circulation Dynamics
Blood Flow Pathways: Summary of how blood circulates during fetal life and the structures involved.
Page 35: Postnatal Changes in Heart Structure
Closure of Vessel Functions: Describes the transition of various fetal structures to their postnatal counterparts.
Page 36: Congenital Heart Defects
Defect Overview: Definition and visual representation of the tetralogy of Fallot and its components.
Page 37: Septum Primum Formation
Formation Process: Details the growth process of septum primum and subsequent openings in the atrial septum.
Page 38: Septum Diagram
Endocardial Cushions: Illustrates the interaction and fusion of the septal structures in the atrioventricular canal.
Page 39: Septum Secundum Development
Fetal Blood Flow: Discussion on how the septum secundum facilitates fetal circulation through the foramen ovale.
Page 40: Valves and Foramen Overview
Structural Framework: Connections and functions of various septal and valvular structures.
Page 41: Changes Post-Birth
Fusion Effects: Describes how changes in blood pressure post-birth impact the atrial septum.
Page 42: Conclusion
Acknowledgment: Thanks for the attention and information presented regarding heart development.
The heart is the first organ to function in the embryo, starting its contraction by day 22 post-fertilization and becoming functional by the fourth week of gestation. Heart development can be visually noted in embryos around 18-19 days when the heart anlage forms at the cephalic ends of the embryonic disc, resulting in a paired structure.
Key components involved in heart development include:
Myoblasts and angiogenic cell clusters
Neural plate
Intraembryonic splanchnic cavity mesoderm
Primitive endoderm node
Cardiogenic field
Notochord
Heart formation occurs through a series of steps starting from the aggregation of splanchnic mesenchymal cells, forming two cardiogenic cords that canalize into endocardial heart tubes, which fuse into a single heart tube. This tube exhibits minor constrictions and begins to segment into:
Sinus venosus
Primitive atrium
Primitive ventricle
Bulbus cordis
Truncus arteriosus
As the heart continues to develop, it loops into a C-shape, positioning the atria cranially and behind the ventricle. Significant changes in ventricular structure are noted between days 20 to 28, leading to the partitioning of the heart into distinct chambers by the second month, notably the atrioventricular canal and various septae forming connections for blood flow.
The heart is the first organ to function in the embryo, starting its contraction by day 22 post-fertilization and becoming functional by the fourth week of gestation. Heart development can be visually noted in embryos around 18-19 days when the heart anlage forms at the cephalic ends of the embryonic disc, resulting in a paired structure.
Key components involved in heart development include:
Myoblasts and angiogenic cell clusters
Neural plate
Intraembryonic splanchnic cavity mesoderm
Primitive endoderm node
Cardiogenic field
Notochord
Heart formation occurs through a series of steps starting from the aggregation of splanchnic mesenchymal cells, forming two cardiogenic cords that canalize into endocardial heart tubes, which fuse into a single heart tube. This tube exhibits minor constrictions and begins to segment into:
Sinus venosus
Primitive atrium
Primitive ventricle
Bulbus cordis
Truncus arteriosus
As the heart continues to develop, it loops into a C-shape, positioning the atria cranially and behind the ventricle. Significant changes in ventricular structure are noted between days 20 to 28, leading to the partitioning of the heart into distinct chambers by the second month, notably the atrioventricular canal and various septae forming connections for blood flow.