superior anterior and posterior medisatina Flashcards
What is mediastinum?
The mediastinum is the central compartment located in the thoracic cavity.
How many divisions and parts does the mediastinum have?
The mediastinum has two divisions but four parts: superior (anterior, middle, posterior) and inferior.
What is the boundary between the superior and inferior divisions of the mediastinum?
The boundary between the superior and inferior divisions of the mediastinum is the T4/5 transthoracic plane or sternal angle.
What are the superior and inferior boundaries of the mediastinum?
The superior boundary of the mediastinum is the superior thoracic aperture, while the inferior boundary is the diaphragm.
What are the lateral boundaries of the mediastinum?
The lateral boundaries of the mediastinum are the pulmonary cavities.
What are the boundaries of the middle mediastinum?
The middle mediastinum is located between the anterior and posterior mediastina, with the superior boundary being the superior mediastinum and the inferior boundary being the diaphragm (T8/9 supine or T9/10 standing).
What are the surface landmarks of the middle mediastinum?
The surface landmarks of the middle mediastinum include the left costal cartilage (CC) and the anterior rib ends III-V.
What structures are found in the middle mediastinum?
The middle mediastinum contains the pericardium, heart, and the origin/root of great vessels.
What is pericardium?
The pericardium is a fibroserous membrane surrounding the heart and is the root of great vessels.
What are the two layers of the pericardium?
The pericardium comprises a fibrous layer (external/tough layer) and a serous layer (internal/serous membrane).
What is the function of the fibrous pericardium?
The fibrous pericardium helps prevent overfilling of the heart.
What are the attachments of the fibrous pericardium?
The fibrous pericardium is superiorly continuous with the adventitia of the great vessels, inferiorly adhered to the central tendon of the diaphragm (pericardiophrenic ligament), anteriorly attached to the sternum (sternopericardial ligaments), and posteriorly loosely adhered to the posterior mediastinum content by loose connective tissue.
What is the serous pericardium?
The serous pericardium is the internal layer of the pericardium and consists of a parietal layer and a visceral layer (epicardium).
What is cardiac tamponade?
Cardiac tamponade occurs when excess fluid within the pericardial cavity prevents the heart’s filling.
What is the pericardial cavity?
The pericardial cavity is a potential space within the serous pericardium that contains fluid.
Where does the reflection of the parietal layer onto the visceral layer occur?
The reflections of the parietal layer onto the visceral layer occur at the origin of the great vessels. The aorta and pulmonary trunk (arterial) and the superior vena cava (SVC), inferior vena cava (IVC), and pulmonary veins (venous) are sites of reflection.
What are pericardial sinuses?
Pericardial sinuses are spaces formed by the reflections of the pericardium, particularly at the origin of the great vessels.
What are pericardial sinuses?
Pericardial sinuses are spaces formed by the parietal layer’s reflection onto the serous pericardium’s visceral layer.
What are the two types of pericardial sinuses?
The two types of pericardial sinuses are the transverse and oblique pericardial sinus.
Where is the transverse pericardial sinus located, and what does it separate?
The transverse pericardial sinus is located between the arterial and venous groups of great vessels. It separates these two groups.
What is the relevance of the transverse pericardial sinus?
The transverse pericardial sinus is important in cardiac surgeries, as the arterial group of great vessels can be cross-clamped during coronary bypass procedures.
Where is the oblique pericardial sinus located?
The oblique pericardial sinus reflects the pericardium around the venous group of great vessels.
What are the blood supply sources to the pericardium?
Several arteries, including the pericardiophrenic artery, musculophrenic artery, coronary arteries, and branches from the thoracic aorta, such as the bronchial artery, esophageal artery, and superior phrenic artery, provide the blood supply to the pericardium.
What are the venous drainage pathways from the pericardium?
The pericardiophrenic vein and tributaries of the azygos venous system drain the pericardium.
What are the three layers of the heart?
The three layers of the heart are the endocardium (inner layer of endothelium and connective tissue), myocardium (middle layer of cardiac muscle cells), and epicardium (outer layer, also known as visceral serous pericardium).
What is the function of the endocardium?
The endocardium is responsible for lining the heart’s inner surface and providing a smooth endothelial surface for blood flow.
What is the myocardium composed of?
The myocardium is composed of cardiac muscle cells (myocytes) and is responsible for heart contraction.
What is another name for the epicardium?
The epicardium is also known as the visceral serous pericardium, the heart’s outer layer.
How many sides does the heart have, and what are they?
The heart has two sides: the right side and the left side.
How many chambers does the heart have, and what are they called?
The heart has four chambers: two atria (receiving chambers) and two ventricles (discharging chambers).
What are the four valves of the heart?
The heart has four valves: two atrioventricular (AV) valves, which are the tricuspid valve on the right side and the mitral (bicuspid) valve on the left side, and two semilunar valves, which are the pulmonary valve and the aortic valve.
What is the function of the right side of the heart?
The right side of the heart receives venous blood from the body and pumps it to the lungs for oxygenation.
What is the function of the left side of the heart?
The left side of the heart receives arterial blood from the lungs and pumps oxygenated blood to the rest of the body.
What happens during the first phase of the cardiac cycle?
Blood enters the atria.
How does blood enter the right atrium?
Blood enters the right atrium through the superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus.