Interior of the heart and posterior mediastinum Flashcards
What is the crista terminalis?
Division in the lungs between muscular and smooth wall
In which chamber of the heart would you expect to find the crista terminalis?
The right atrium
In which chamber of the heart would you expect to see the fossa ovalis?
Right atrium
What is the fossa ovalis?
Oval shaped depression on the inter atrial septum of the right ventricle
The fossa ovalis a remnant of which foetal structure?
Foramen ovale
What was the function of the foramen ovale in foetal development?
Allow blood flow between right and left sides of the heart
What are the cordae tendinae?
chords that are attached to the tricupsid valves and papillary muscles?
What are the papillary muscles
Finger-like muscles that project from the interior wall og the heart.
What are the trabeculae canae?
Spiderweb like fibres that look similar to the papillary muscles but are not connected to cordae tendinae
Where does the moderator band connect with?
Connects to base of anterior papillary muscle of the tricupsid valve and to the ventricular septum
What is the purpose of the trabeculae canae?
Connects branch of AV bundle to papillary muscle to save conduction time
Do papillary muscles contract before or after the ventricles?
At the same time
What is the purpose of the cordae tendinae and papillary muscles?
They contract with ventricles in order to stop tricuspid from becoming averted during increased pressure of ventricular contraction
What is the difference in the right and left atrial walls?
Right atrium has muscular a smooth side separated by crista terminalis.
Left atrium just has smooth walls
What is the intraventricular and interventricular?
itra = within inter=between
When does the foramen ovale close?
After birth
If holes persist in the foramen ovale, is this clinically significant?
Atrial septum defect - can cause major problems as deoxygenated blood will be pumped through the aorta so lowered oxygen saturation levels
Describe the spread of excitation of the heart
SAN starts the excitation (no stable resting potentials so can depolarise spontaneously. Propagates through atria gap junctions
Impulse spreads over ventricles so atria contract simultaneously
Impulses reach AV node
Impulse slowed to allow impulse to allow atria to empty fully
AVN sends impulse through septum though AV bundles to apex
Pukenje fibres conduct impulse from apex upwards on the ventricles to push blood through semi lunar valves
What is incompetence of the heart valves?
Incomplete closure of valves during contraction
What is stenosis of the heart valves?
Incomplete opening of the valves when blood is passing through
If there is a ventricular septum defect, which does direction would the blood flow within the heart?
Left to right ventricle
If the left atrioventricular valve was malfunctioning, what would occur?
Flowback into the left ventricle and increased pressure in the left atrium and pulmonary vein
During foetal development, the dustus artieriosus would allow blood flow in the heart from which side?
Left to right
What is coarctation of the aorta?
arch of descending aorta is locally constricted
Where is coarctation of the aorta most likely to occur?
Below the left subclavian artery
What intercostal marks the division between super and inferior border of the mediastinum?
T4/5
What feature of the sternum and which vertebral disc mark the inferior border of the superior portion of the mediastinum?
Sternal angle and the vertebral disk between T4/5
What can be found between the heart and the sternum?
Remembrance of the thymus gland
Where is the heart located within the mediastinum?
The medial layer of the inferior portion of the mediastinum
What feature can be found on the portion of the inferior mediastinum?
The remnance of the thymus gland
What is found in the posterior portion of the inferior mediastinum?
All components below the heart
What great vessels can be found in the superior portion of the mediastinum?
Superior vena cava: brachiosephalic veins, internal jugualar and subclavian
Vena cava: brachiosephalic trunk, L+R common caroid and L+R subclavian
Where can the trachea be seen?
Between brachiosephalic trunk and common carotid
Where is the conrina and the left and right main bronchi found within the mediastinum?
Posterior portion of the inferior mediastinum
Where is the oesophagus found in relation to the thrachea
Immediately deep to it. Left main bronchus lies directly above it.
What vessel is found lateral to the left of the oesophagus?
Descending aorta
What vessel is found deeper to the oesophagus on its right lateral side?
Azygous vein
Where does the azygous vein receive blood from?
Intercostal veins
Where the azygous vein drain into?
Superior vena cava
Where can the thoracic duct be found?
between azygous vein and oesophagus
What does thoracic duct carry and from where?
Lymph and carries it from the abdominal region and lower body
Where does the thoracic duct drain into?
Runs superiorly into the left braciosephalic vein
