Powerpoint 1 - Intro Flashcards
Superior mediastinum contains:
Aortic arch, SVC
Brachiocephalic arteries and veins Proximal segments of the lt CCA and lt subclavian artery
Parts of thymus gland, lymph nodes, & nerves Trachea, esophagus
Inferior mediastinum is divided into 3 parts:
Anterior mediastinum – lies anterior to heart and contains lymph nodes, muscles, and small blood vessels
Middle mediastinum –contains the heart, pericardium, ascending ao, terminal end of SVC, PA and branches, terminal parts of rt and lt pulmonary veins, & phrenic nerves
Posterior mediastinum – contains the descending thoracic ao, bifurcation of the trachea, rt and lt main bronchi, the esophagus, the azygous and hemiazygous veins, the splenic nerves, and thoracic lymphatic duct
These 2 interfere with sound wave transmission
Air and bone
During inspiration:
The diaphragm contracts and moves down Intrathoracic pressure decreases allowing air into the lungs
Deep inspiration and holding it may enhance the ability to image the heart by increasing the size of the intercostal space
On test: what happens? VENOUS RETURN DECREASES… harder for blood to travel upward due to the increased pressure from the diaphragm on the abdominal cavity
What ribs during inspiration?
4th and 5th
During expiration:
The diaphragm moves upward
Intrathoracic pressure increases and forces air out
Holding the breath out m ay enhance the US image by preventing expansion of the lungs within the thoracic cavity
On test: venous return INCREASES to heart… less pressure from the diaphragm on abdominal cavity
Easier to take pictures on inspiration or expiration?
Depends on the axis in which you’re imaging
Inspiration involves expansion in what 2 ways
Anteroposterior expansion AND lateral expansion
Pericardium made of two components
Fibrous pericardium
Tough outer sac made of connective tissue which completely surrounds heart but doesn’t adhere to or touch it
It is continuous with the adventia of the great vessels superiorly
AND
Serosal (inner) pericardium WHICH HAS 2 layers
Visceral or epicardial layer adheres to the surface of the heart and makes up the epicardium
At the base of the heart, at the origin of the great vessels, the serosal pericardium folds back on itself to form the outer or parietal layer
2/3 of what and 1/2 of what lie within the pericardium?
2/3 of the proximal ascending aorta and main pulmonary artery and
1⁄2 of the of the SVC
This is why type A (ascending) aortic dissections will result in rapid fluid accumulation around the heart and tamponade
Fluid accumulates in the pericardial space between the serosal layers of pericardium
Function of the pericardium
Reduce friction with cardiac movement
Allow the heart to move freely with each beat, facilitating ejection and volume changes
Contain the heart within the mediastinum, esp. during trauma
Serve as a barrier to infection
Know how to label this photo
Review “TEST PICS” on ipad Notes
What’s responsible for perfusing heart muscle and its inner structures?
The coronary arteries
Why are the coronary arteries named such?
Because the network of arteries form a crown around the heart
Origin of the Left Coronary Artery
Originates above the valve at the left sinus of Valsalva as the left main coronary
Talk more about the Left Coronary Artery and its anatomy
The left main coronary bifurcates almost immediately into the left anterior descending (LAD) and left circumflex arteries
The Left Coronary Artery (LCA) supplies blood to where exactly?
It supplies the LEFT atrium, LEFT ventricle, and segments of the interventricular septum
The Right Coronary Artery originates where?
Originates above the valve at the right sinus of Valsalva
Anatomy of the Right Coronary Artery
Courses in the atrioventricular groove
The Right Coronary Artery supplies what part of the heart with blood?
It supplies the right atrium, right ventricle, and segments of the interventricular septum
What DRAINS the heart muscle?
Cardiac veins
The cardiac veins, their anatomy…
Usually course with the arteries