Anatomy of Thorax Flashcards
What fuses to become the primitive heart tube?
Paired endothelial tubes
What are the 5 regions of the pericardial cavity?
Sinus venosus, Atrium, Ventricle, Bulbus cordis and truncus arteriosis.
Sinus venosus becomes incorporated into what?
The atrium
What part of the pericardial cavity tube incorporates into the ventricle?
The bulbus cordis
How does the interventricular septum develop?
From the apex upwards towards the endothelial cushions
Fusion of what leads to the formation of the foramen secundum?
The septum primum fuses with the endocardial tissues
What two defects form the foramen ovale?
Septum secundum
Septum primum
What is the purpose of the foramen ovale:
Allows blood to go directly from the right to the left side f the heart in a developing foetus. The septum secundum acts as a valve like structure to facilitate this.
How does the foramen ovale close?
After birth there is an increased blood flow through the lungs which causes a rise in left atrial pressure - the septum primum is then pushed across to close the foramen ovale.
What is the name given to the residual dimple after the foramen ovale closes:
The fossa ovalis
What is the most common type of cardiac defect?
Ventricular septal defect
What defect causes increased load on the left ventricle and can lead to pulmonary hypertension?
Patent ductus arteriosus
When surgically (open) repairing a patent ductus arteriosus, what vessel must you take care to avoid?
The LEFT recurrent laryngeal nerve
What is reverse shunting
Right to left shunting / flow of blood
Increased ___________ flow leads to reverse shunting
Pulmonary
What defects can lead to reverse shunting
ASD, VSD and PDA
What is the name for cyanosis secondary to reverse shunting
Eisenmenger’s syndrome
What congenital condition can lead to Eisenmenger’s syndrome
Tetralogy of Fallot
What are the four components of tetralogy of fallot:
VSD
Stenosed pulmonary outflow tract
Right ventricular hypertrophy.
Wide aorta overriding the right and left ventricles.
The degree of cyanosis depends on the degree of what?
The severity of pulmonary outflow obstruction
When is notching of the rib inferior border seen on a CXR and what condition causes this?
When patient has enlarged intercostal arteries which become torturous
Caused by Coartication of the aorta
Delayed / weak / absent femoral pulses are seen in what condition:
Coartication of the aorta
What are the 4 developmental parts of the diaphragm?
Septum Transversum
Mesentery of the foregut
Ingrowth from the body wall
Pleuroperitoneal membrane
Which rib does the scalenus anterior insert onto?
Rib 1 - upper surface prominent tubercle
What vessel crosses the first rib infront of the scalene tubercle?
The subclavian vein
What is the incidence of cervical ribs?
1 in 200
( 1 in 500 if bilateral)
What is the superior border of the superior mediastinum?
Thoracic inlet
What is the onferior border of the superior mediastinum?
Continuous with the inferior mediastinum
What is the anterior border of the superior mediastinum?
Manubrium of sternum
What is the posterior border of the superior mediastinum?
Vertebral bodies of T1 to T4
What is the Lateral border of the superior mediastinum?
Pleura of lungs
What vessels are found in the superior mediastinum?
Arch of the aorta -
- brachiocephalic (right only),
- left common carotid
- left subclavian
Superior vena cava -
- Azygous vein
- Brachiocephalic vein
- Left intercostal vein
- Supreme intercostal vein
What nerves are found in the superior mediastinum?
Vagus nerve - right and left
Phrenic nerve
Cardiac nerves
Sympathetic trunk
List structures found within the superior mediastinum:
Thymis
Trachea
Oesophagus
Thoracic duct
What muscles are found within the superior mediastinum?
Sternohyoid
Sternothyroid
At what level is the mediastinum segregated into superior and inferior compartments:
T4 (aka sternal angle)