dr. ahmed fathalla ibrahim. early development of heart in cardiogenic areasplanchnic mesenchymal...
TRANSCRIPT
![Page 1: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/1.jpg)
Dr. Ahmed Fathalla Ibrahim
![Page 2: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/2.jpg)
EARLY DEVELOPMENT OF EARLY DEVELOPMENT OF HEARTHEART
• Splanchnic mesenchymal cells aggregate in cardiogenic areain cardiogenic area to form two angioblastic cords
• Cords canalize to form two endocardial two endocardial heart tubesheart tubes
• After folding:After folding:1. The 2 tubes approach each other & fuse fuse
(cranio-caudally)(cranio-caudally) to form a single heart tubea single heart tube2. The heart tube becomes caudal to
oropharyngeal membrane
![Page 3: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/3.jpg)
EARLY DEVELOPMENT OF EARLY DEVELOPMENT OF HEARTHEART
![Page 4: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/4.jpg)
EARLY DEVELOPMENT OF EARLY DEVELOPMENT OF HEARTHEART
The heart tube elongates & forms:
1.1. Truncus arteriosusTruncus arteriosus
2.2. Bulbus cordisBulbus cordis
3.3. VentricleVentricle
4.4. AtriumAtrium
5.5. Sinus venosusSinus venosus
![Page 5: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/5.jpg)
EARLY DEVELOPMENT OF EARLY DEVELOPMENT OF HEARTHEART
• The trucus arteriosusThe trucus arteriosus is continuous cranially with aortic sac from which aortic arches arise
• The sinus venosusThe sinus venosus lies in the septum transversum & receives umbilical, vitelline & common cardinal veins
So:So:• The arterial & venous ends of heart are
fixed by pharyngeal arches & septum transversum, respectively
![Page 6: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/6.jpg)
EARLY DEVELOPMENT OF EARLY DEVELOPMENT OF HEARTHEART
• The bulbus cordis & ventricle grow fastergrow faster than atrium & sinus venosus:
1. The heart bends upon itself forming a U-U-shaped loopshaped loop
2. The atrium and sinus venosus become dorsaldorsal
3. A track is formed between arterial & venous end (transverse pericardial sinus)(transverse pericardial sinus) after degeneration of dorsal mesocardiumafter degeneration of dorsal mesocardium
![Page 7: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/7.jpg)
PARTITIONING OF PARTITIONING OF ATRIOVENTRICULAR CANALATRIOVENTRICULAR CANAL
![Page 8: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/8.jpg)
PARTITIONING OF PARTITIONING OF ATRIOVENTRICULAR CANALATRIOVENTRICULAR CANAL
• At the end of 4th week, 2 mesenchymal thickening (endocardial cushions)(endocardial cushions) form on the dorsal & ventral walls of atrioventricular canal
• The 2 dorsal & ventral cushions fuse & divide AV canal into right & left canalsdivide AV canal into right & left canals
• The 2 cushions contribute to the formation of:
1.1. AV valvesAV valves2.2. Membranous part of interventricular Membranous part of interventricular
septumseptum
![Page 9: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/9.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL ATRIUMATRIUM
![Page 10: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/10.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL ATRIUMATRIUM
![Page 11: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/11.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL ATRIUMATRIUM
• Septum primum:Septum primum: a crescent-shaped septum arises from the roof of the atrium & grows toward the endocardial cushions.
• Foramen primum:Foramen primum: an opening between edge of septum primum & cushions. It disappears when septum primum fuses with cushions
![Page 12: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/12.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL ATRIUMATRIUM
• Foramen secundum:Foramen secundum: formed by fusion of many perforations appearing in the central part of septum primum
• Septum secundum:Septum secundum: a crescent-shaped septum arises from the roof of atrium to the right of septum primum & overlaps foramen secundum
![Page 13: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/13.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL ATRIUMATRIUM
• Foramen ovale:Foramen ovale: a defect between primary & secondary septum that allows passage of most of oxygenated blood from right to left atrium. Later on, the cranial part of septum primum degenerates & its remaining part forms a valve for the oval foramena valve for the oval foramen preventing the passage of blood in the opposite direction
![Page 14: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/14.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL ATRIUMATRIUM
AFTER BIRTH: AFTER BIRTH: • Due to equalization of pressure on both
atria, the foramen ovale closes & both septa fuse to form the interatrial septum
• Fossa ovalis:Fossa ovalis: remnant of septum primum septum primum (valve of foramen ovale),(valve of foramen ovale), marks site of foramen ovale
• Annulus ovalis:Annulus ovalis: remnant of septum septum secundumsecundum
![Page 15: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/15.jpg)
CHANGES IN SINUS VENOSUSCHANGES IN SINUS VENOSUS
![Page 16: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/16.jpg)
CHANGES IN SINUS VENOSUSCHANGES IN SINUS VENOSUS
• Initially,Initially, sinus venosus opens into the atrium & is formed of 2 equal horns
• Right hornRight horn: enlarges & becomes incorporated in the wall of right atriumincorporated in the wall of right atrium
• The valve between right horn & right The valve between right horn & right atrium:atrium: its cranial partits cranial part forms crista terminalis; its caudal partits caudal part forms valves of IVC and coronary sinus
![Page 17: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/17.jpg)
CHANGES IN SINUS VENOSUSCHANGES IN SINUS VENOSUS
• The valve between left horn & left The valve between left horn & left atrium:atrium: forms part of interatrial septum
• Left horn:Left horn: remains small & forms the coronary sinus
![Page 18: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/18.jpg)
Primordial pulmonary veinPrimordial pulmonary vein
![Page 19: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/19.jpg)
Primordial pulmonary veinPrimordial pulmonary vein
• Develops as an outgrowth of dorsal outgrowth of dorsal atrial wall, to the left of septum primumatrial wall, to the left of septum primum
• Divides into two branches then into 4 branches
• As atrium expands, the stem of pulmonary vein & its main branches are gradually incorporated into the wall of gradually incorporated into the wall of left atriumleft atrium
![Page 20: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/20.jpg)
SUMMARY OF DEVELOPMENT SUMMARY OF DEVELOPMENT OF RIGHT ATRIUMOF RIGHT ATRIUM
• Muscular part:Muscular part: primordium atrium• Smooth part:Smooth part: right horn of sinus venosus• Fossa ovalis:Fossa ovalis: part of septum primum• Annulus ovalis:Annulus ovalis: part of septum secundum• Crista terminalis:Crista terminalis: cranial part of right sinuatrial
valve• Valves of IVC & coronary sinus:Valves of IVC & coronary sinus: caudal part of
right sinuatrial valve• Interatrial septum:Interatrial septum: fused septum primum &
secundum + left sinuatrial valve• Coronary sinus:Coronary sinus: left horn of sinus venosus
![Page 21: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/21.jpg)
SUMMARY OF DEVELOPMENT SUMMARY OF DEVELOPMENT OF LEFT ATRIUMOF LEFT ATRIUM
• Left auricle: Left auricle: primordium atrium• Rest of left atrium (smooth part): Rest of left atrium (smooth part): stem
of pulmonary vein & its main branches
![Page 22: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/22.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL VENTRICLEVENTRICLE
![Page 23: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/23.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL VENTRICLEVENTRICLE
• Muscular part of interventricular Muscular part of interventricular septum:septum: a crescentic fold with a concave cranial edge arises from the floor of ventricle (near its apex) & grows toward fused endocardial cushions
![Page 24: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/24.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL VENTRICLEVENTRICLE
• Interventricular foramen:Interventricular foramen: an opening between muscular part of septum & cushions. It is closed closed (7th week) as a result of fusion offusion of : right & left bulbar ridges + endocardial cushions
![Page 25: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/25.jpg)
PARTITIONING OF PRIMORDIAL PARTITIONING OF PRIMORDIAL VENTRICLEVENTRICLE
• Membranous part of Membranous part of interventricular septum: interventricular septum: derived from an extension from right side of endocardial endocardial cushioncushion
![Page 26: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/26.jpg)
PARTITIONING OF BULBUS CORDIS PARTITIONING OF BULBUS CORDIS & TRUNCUS ARTERIOSUS& TRUNCUS ARTERIOSUS
![Page 27: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/27.jpg)
PARTITIONING OF BULBUS CORDIS PARTITIONING OF BULBUS CORDIS & TRUNCUS ARTERIOSUS& TRUNCUS ARTERIOSUS
• During 5During 5thth week week, mesenchyme derived from mesenchyme derived from neural crest cellsneural crest cells proliferate to form bulbar bulbar & truncal ridges& truncal ridges that are continuous with each other
• Ridges are spirally orientedspirally oriented• Bulbus cordisBulbus cordis is divided into conus conus
arteriosus (infundibulum)arteriosus (infundibulum) & aortic vestibuleaortic vestibule• Truncus arteriosusTruncus arteriosus is divided into:
pulmonary trunkpulmonary trunk & ascending aortaascending aorta
![Page 28: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/28.jpg)
SUMMARY OF DEVELOPMENT SUMMARY OF DEVELOPMENT OF RIGHT VENTRICLEOF RIGHT VENTRICLE
• Muscular part: Muscular part: primordium ventricleprimordium ventricle
• Infundibulum: Infundibulum: bulbus cordisbulbus cordis
![Page 29: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/29.jpg)
SUMMARY OF DEVELOPMENT SUMMARY OF DEVELOPMENT OF LEFT VENTRICLEOF LEFT VENTRICLE
• Muscular part: Muscular part: primordium ventricleprimordium ventricle
• Aortic vestibule: Aortic vestibule: bulbus cordisbulbus cordis
![Page 30: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/30.jpg)
DEVELOPMENT OF VALVESDEVELOPMENT OF VALVES
• Develop as swellings arising from localized proliferations of tissue:
1. Around AV canals (AV valves)(AV valves)
2. Around orifices of aorta & pulmonary trunk (semilunar valves)(semilunar valves)
• Swellings are hollowed out & reshaped to form the cusps
![Page 31: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/31.jpg)
CONGENITAL HEART DEFECTSCONGENITAL HEART DEFECTS
• Are commoncommon (0.6 -0.8%)
• Caused byCaused by genetic abnormalities, rubella virus or by environmental factors
• Some are with unknown cause
![Page 32: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/32.jpg)
DEXTROCARDIADEXTROCARDIA
• Most frequent positional abnormalityMost frequent positional abnormality
• Cause:Cause: heart tube bends to the left
• Results:Results: heart is displaced to the right
• Occurrence:Occurrence: isolated or with situs inversus
![Page 33: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/33.jpg)
ATRIAL SEPTAL DEFECTATRIAL SEPTAL DEFECT
• More frequent in femalesfemales
• Most common form:Most common form: patent patent foramen ovaleforamen ovale (due to incomplete adhesion between septum primum & secundum)
![Page 34: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/34.jpg)
ATRIAL SEPTAL DEFECTATRIAL SEPTAL DEFECT
• Other forms:1.1.Ostium secundum defect:Ostium secundum defect: due to defect
in one or both septa2.2.Endocardial cushions defects with Endocardial cushions defects with
ostium primum:ostium primum: septum primum does not fuse with cushions resulting in a patent forament primum
3.3.Sinus venosus defect:Sinus venosus defect: incomplete absorption of sinus venosus
4.4.Common atrium:Common atrium: failure of both septa to develop
![Page 35: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/35.jpg)
VENTRICULAR SEPTAL DEFECTVENTRICULAR SEPTAL DEFECT
• Most common typeMost common type of congenital heart diseases
1.1. Membranous VSDMembranous VSD (most common):(most common): incomplete closure of IV foramen due to failure of membranous part of septum to develop
2.2. Muscular VSDMuscular VSD3.3. Common ventricle:Common ventricle: absence of whole
IV septum
![Page 36: Dr. Ahmed Fathalla Ibrahim. EARLY DEVELOPMENT OF HEART in cardiogenic areaSplanchnic mesenchymal cells aggregate in cardiogenic area to form two angioblastic](https://reader030.vdocument.in/reader030/viewer/2022033106/56649cc05503460f9498775f/html5/thumbnails/36.jpg)
ECTOPIA CORDISECTOPIA CORDIS
• Very rareVery rare• Heart is partly or completely exposed on partly or completely exposed on
the surface of thoraxthe surface of thorax• Usually associated with separated halves
of sternum & open pericardial sac• Cause:Cause: faulty development of sternum &
pericardium due to failure of complete fusion of lateral folds in formation of thoracic wall