Development and anatomy Flashcards
First system to function in embryo
Cardiovascular system
Heart will be anterior to
Oropharyngeal membrane
What attaches heart to wall
Dorsal mesocardium
What forms the coelomic cavity
Serous pericardium: visceral and parietal pericardium
Fibrous pericardium
Pericardial cavity between visceral and parietal
At what day do heart tubes fuse in midline
Day 19
At what day does blood flow start and pumping heart
Day 21
What forms the pulmonary artery
Truncus arteriosus
What will form the diaphragm
Septum transversum
At what day does the heart get bigger at level of ventricle and atrium
Day 22, 23
How does the heart adopt an S-shape
By folding on itself
Where will ventricles move during folding of heart
Ventrally and to the right
Where will atrium move during folding of heart
Dorsally and to the left
Why are the atria at the back in adult heart
Due to folding of atrium dorsally and to the left during fetal development
Truncus arteriosus –>
Aorta/pulmonary trunk
Conus arteriosus –>
Right + left ventricle (smooth part)
Primitive ventricle
Right and left ventricle (trabecular part)
Primitive atrium
Right and left atrium (trabecular part)
Sinus venosus –>
Right atrium smooth part + coronary sinus
When will the dorsal mesocardium dissapear
When heart attached to vessels and arteries
Space: transverse pericardial sinus
What is sinus venosus
Opening going to the common atrium
Location of sinus venosus
Right side
Which vein does not have a valve
Superior cava vein
What are endocardial cushions
2 thick areas developing in walls that divide the 4 chambers of the heart
From where will endocardial cushions be formed
Neural crest cells
From where will tricuspid and mitral valve be formed
Neural crest cells
What connects atriums
Ostium primum
What closes the ostium primum
Endocardial cushions
Formation of ostium secundum becasue
There needs to be a communication between atria so through apoptosis small holes apear in septum primum for communication
Formation of ostium secundum becasue
There needs to be a communication between atria so through apoptosis small holes apear in septum primum for communication
Characteristics of 1st septum
Flexible and thin
Characteristics of septum secundum
Flexible and thick
Formation of oval foramen
From the growth of septum secundus (flexible and thicker) that will leave an opening
More blood on right or left side
Right
Ductus arteriosus
Blood vessel connecting aorta and pulmonary artery
To what does the ductus arteriosus turn into after birth
Arteriosus ligament
Why does oval foramen close after birth
Because there is a drop in pressure in right side
And an increase of pressure on left side
Name of oval foramen after birth (closure)
Fossa ovalis
Changes at birth Umbilical vein --> Ductus venosus --> Foramen ovale --> Ductus arteriosus -->
Lig. teres
Lig. venosum
Fossa ovalis
Lig. arteriosum
Atrial septal defects: Ostium primum defect
Endocardial cushion defect –> communication between 2 atrium after birth
Atrial septal defects: Ostium secundum defect
Maintained due to excessive apoptosis
Most important defect
Interventricular communication
Closure of interventricular foramen
7th week
What completes the septum
Bulbus cordis
Acyanotic condition
Heart defect affecting normal blood flow
What results from ventricular septal defect
Acyanotic condition due to pressure being higher on left side, so blood will go to right side
What results from pulmonary stenosis
Interventricular septum defect
Overriding aorta
Hypertrophy of right ventricle
