Embryology Flashcards
What part of the primitive heart tube does the Aorta and Pulmonary Trunk arise from?
Trunks Arteriosus
What part of the the primitive heart does the smooth wall of the right and left ventricles arise from?
Conus Cordis
What part of the adult heart does the Primitive Ventricle become?
Trabeculated part of the Left Ventricle
What part of the adult hart does the Primitive Atrium become?
The Trabeculated parts of the left and right atria
What part of the primitive heart tube does the Smooth Part of the Right Atrium arise from?
Sinus Venosus
What part of the primitive heart tube does the Coronary Sinus and Oblique Vein of the Left Ventricle Arise from?
Sinus Venosus
What is a Blastocyst?
A hollow ball of cells
What part of the embryo implants the Blastocyst into the uterine lining and eventually becomes the Placenta?
Trophoblast
What happens in Day 15 after the egg has been fertilised?
Gastrulation
What are the layers of the Trilaminar Disc?
- Ectoderm
- Endoderm
- Mesoderm
What does the Ectoderm form?
All epidermis and nervous system
What does the Endoderm form?
Inner lining of the GI tract and Respiratory Tract
What does the Mesoderm form?
Bone, Muscle, Connective Tissue and Dermis
When does Neural Tube Formation start?
Day 17-18
What happens in Neural Tube Formation?
Ectoderm thickens and folds to form a groove
When does Neural Tube Closure occur?
Day 22
When does Neural Tube Closure complete?
Day 27
What are the 3 components of the Mesoderm?
- Paraxial
- intermediate
- Lateral
What are Somites?
Paired aggregations of mesoderm cells cuboid in shape
What is the importance of Somites?
They from most of the Axial Skeleton including the Vertebral Column
What is Teratogenesis?
Malformation of the Foetus
Describe the Sinus Venous?
- It has Right and Left Sinus Horns
2. Each Sinus Horn receives: Vitamin Vein, Umbilical Vein and Common Cardinal Veins (Anterior and Posterior)
What happens to the Sinus Venous during development?
- The entrance of Sinus Venous narrows and moves right
- Right umbilical vein and Left vitamin veins vanish
- The 2 Anterior Cardinal Veins join to form the Left Brachiocephalic Vein
- The left sinus horn gets smaller and becomes the Oblique vein of left atrium and the coronary sinus
What happens to the trunks of the Primitive Aorta in development?
- !st, 2nd and 5th Trunk disappears
- 3rd Arch becomes the Carotids
- 4th Arch becomes the arch of aorta and subclavian artery
- The 6th trunk becomes the Pulmonary Trunk and Ductus arteriosus
What happens to the Viteline Veins in development?
- Left side mostly obliterates
2. Right side forms the Hepatocardiac Inferior Vena Cava, Portal Vein and Superior Mesenteric Vein
What do the happens to the Cardinal Veins in development?
- Supracardinal Veins drain the body wall–> become the Azygous System
- Subcardinal Veins drain the Kidney
- Sacrocardinal Veins drain the Lower Extremeties
- Anterior Cardinal Vein forms the Superior Vena Cava
- Posterior Cardinal Veins mostly obliterate
What are the right to left shunts in the Fetal circulation?
- Atrial Septum
2. Ductus Arteriosus
What are Acyanotic Shunts?
Left to Right Shunts–> in Atrial Septal Defect, Ventricular Septal Defect, And PDA
What are Cyanotic Shunts?
Right to Left Shunts–> Reduces flow to Pulmonary Circulation
What are the 5 Cyanotic Shunts?
- Tetralogy of Fallot
- Transposition of Great Vessels
- Trunks Arteriosus
- Tricuspid Atresia
- TAPVR
What is Tetralogy of Fallot?
Unequal division of the Conus Cordis (When the Septum is too anterior)–> Causes Pulmonary Stenosis, large Ventricular Septal Defect, Overriding Aorta and Hypertrophy of the Right Ventricle
