SFP: Middle Mediastinum And Heart Flashcards
What defines the middle mediastinum?
The pericardium
The middle mediastinum is a compartment in the thoracic cavity that contains the pericardium.
What are the contents of the middle mediastinum?
- Pericardium
- Heart
- Origins of great vessels
- Nerves (phrenic NN and cardiac plexus)
- Smaller vessels
These structures are essential for the function and support of the heart.
Describe the fibrous pericardium.
The fibrous pericardium is the outer layer of the pericardial sac that blends with adventitia of the great vessels. It is attached on the superior surface of the diaphragm.
This layer provides structural support and protection to the heart.
What are the two layers of serous membrane within the pericardium?
- Parietal (the lining of the sac)
- Visceral (on the heart surface)
The pericardial cavity is located between these layers and contains fluid for lubrication.
What are the layers of the pericardium from superficial to deep?
- Fibrous outer layer
- Parietal serous layer
- Pericardial cavity
- Visceral serous layer
This organization is important for the overall function and protection of the heart.
What are pericardial reflections?
Areas where the visceral and parietal layers of the pericardium meet at a great vessel
These reflections are crucial for the attachment and support of the heart.
Where are arterial reflections seen?
- Aorta
- Pulmonary trunk
These areas are significant for the outflow of blood from the heart.
Where are venous reflections seen?
- SVC
- IVC
- Pulmonary veins
These reflections are important for the return of blood to the heart.
What is a pericardial sinus?
Spaces between arterial and venous reflections
These sinuses play a role in the movement and positioning of the heart within the pericardial cavity.
Which great vessels are in the pericardial sac?
SVC, IVC, ascending aorta, and pulmonary trunk
What are the semilunar valves?
Aortic and pulmonary
Does the right or left ventricle tend to be anterior?
Right
What is the coronary sulcus?
Structure found between the atria and ventricles
What is the interventricular sulcus?
Structure that separates ventricles
Describe the first step in the development of sinuses.
The heart begins its development as a tube
Describe the second step in the development of sinuses.
The heart begins to bend and loop as it forms
What does the loop of the heart form during development?
A transverse pericardial sinus
What structures can be found posterior to the pericardium in the posterior mediastinum?
Descending aorta, esophageal arteries, esophagus, L vagus nerve, and esophageal nerve plexus
The right coronary artery branches into which arteries?
The right coronary artery that extends over the right chamber anteriorly and the posterior descending artery
Fill in the blank: The area where the primordial arterial and venous ends are brought together forms the _______.
transverse pericardial sinus
True or False: The left ventricle is typically positioned anteriorly.
False
What is the role of the parietal pericardium?
It forms the outer layer of the pericardial cavity
What is the significance of the primordial heart tube?
It is the initial structure from which the heart develops
What happens to the veins during the development of the pericardium?
Veins expand and pericardial reflection is carried out around them to form oblique pericardial sinuses
What is the function of small cardiac veins?
Small cardiac veins drain the right ventricle to the coronary sinus
These veins play a crucial role in the venous drainage of the heart.
The left coronary artery branches into which two arteries?
Circumflex artery and left anterior descending artery
The left anterior descending artery is also known as the anterior interventricular artery.
What is the role of the great cardiac vein?
The great cardiac vein drains the left ventricle
This vein is important for the venous return from the heart’s muscular walls.
Where is the middle cardiac vein located and what does it drain into?
Found on the posterior side of the heart and drains into the coronary sinus
It is essential for draining the blood from the heart’s posterior regions.
What structure does the coronary sulcus define?
Coronary sulcus separates the atria from the ventricles
This groove is significant for the layout of the heart’s anatomy.
What are the main components of blood flow through the heart?
- Blood returns to the heart into the right atrium via the vena cava (inferior or superior)
- Blood passes through the tricuspid valve into the right ventricle
- Blood pumps to the lungs out of the right ventricle through the pulmonary valve via the pulmonary artery
- Oxygenated blood returns to the left atrium via pulmonary veins
- Blood passes to the left ventricle through the mitral valve
- Blood enters the aorta via the aortic valve and is pumped to the body
This sequence outlines the systemic and pulmonary circulation processes.
Fill in the blank: The _______ artery is also called the left anterior descending artery.
Anterior interventricular artery
This artery is critical for supplying blood to the interventricular septum and parts of the ventricles.
True or False: The right coronary artery supplies blood to the left ventricle.
False
The left coronary artery primarily supplies the left ventricle.
What does the right marginal artery supply?
Supplies the right ventricle
It is an important artery for the right heart’s blood supply.
What is the function of the anterior cardiac veins?
Drain blood from the right ventricle directly into the right atrium
These veins provide an alternative route for venous return from the right ventricle.
What is the posterior interventricular artery also known as?
Posterior descending artery
This artery is crucial for supplying the inferior part of the heart.
What are the 3 layers of the heart wall?
Epicardium, myocardium, endocardium
These layers each serve distinct functions and structures within the heart.
What is the epicardium?
Visceral layer of serous pericardium
It is the outermost layer of the heart wall.
What is the myocardium?
Cardiac muscle
This layer is responsible for the contraction of the heart.
What is the endocardium?
Endothelium lining of the heart lumen; continuous with the vessels
It provides a smooth lining for the heart chambers.
Most ventricular septal defects come from…
The membranous part of the interventricular septum not closing properly
This is a common congenital heart defect.
What is the space just under the valves called?
The aortic vestibule
It is the area leading into the aorta from the left ventricle.
What is the function of the SA node?
It sends a signal through the atria and reaches the sulcus between the two sides, meeting the AV node
The SA node is considered the pacemaker of the heart.
What does the AV node do?
The signal from the AV node goes through the Purkinje fibers and AV bundle branches to each ventricle
This is crucial for coordinating the contraction of the ventricles.
Which artery provides blood supply to the SA and AV nodes?
Right coronary artery
The right coronary artery is essential for the proper functioning of the heart’s conduction system.
Where is the apex of the heart located?
The 5th intercostal space, 3 inches left of the midsternal line
This location is important for auscultation and clinical assessments.
Where is the superior border of the heart found?
Left 2nd costal cartilage to right 3rd costal cartilage
This border is significant for identifying the heart’s position in the thoracic cavity.
Where is the right border of the heart located?
From the end of the superior border to the 6th costal cartilage
Understanding the heart’s borders aids in imaging and surgical approaches.
Where is the left border of the heart found?
From the end of the superior border to the apex
The left border is crucial in determining the heart’s silhouette on chest X-rays.
Where is the inferior border of the heart located?
From the right 6th costal cartilage to the apex
This border helps in assessing the heart’s position relative to other thoracic structures.
Where is the pulmonary valve located?
Connects right ventricle to pulmonary artery
The pulmonary valve is essential for directing blood flow to the lungs.
Where is the aortic valve found?
Connects left ventricle to aorta
This valve is key for systemic blood circulation.
Where is the mitral valve located?
Connects left atrium to left ventricle
The mitral valve plays a critical role in preventing backflow during ventricular contraction.
Where is the tricuspid valve located?
Connects the right atrium to the right ventricle
The tricuspid valve is important for maintaining unidirectional blood flow within the heart.
