SFP: Middle Mediastinum And Heart

Question 1

What defines the middle mediastinum?

Answer 1

The pericardium

The middle mediastinum is a compartment in the thoracic cavity that contains the pericardium.

Question 2

What are the contents of the middle mediastinum?

Answer 2

• 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.

Question 3

Describe the fibrous pericardium.

Answer 3

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.

Question 4

What are the two layers of serous membrane within the pericardium?

Answer 4

• Parietal (the lining of the sac)
• Visceral (on the heart surface)

The pericardial cavity is located between these layers and contains fluid for lubrication.

Question 5

What are the layers of the pericardium from superficial to deep?

Answer 5

• Fibrous outer layer
• Parietal serous layer
• Pericardial cavity
• Visceral serous layer

This organization is important for the overall function and protection of the heart.

Question 6

What are pericardial reflections?

Answer 6

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.

Question 7

Where are arterial reflections seen?

Answer 7

• Aorta
• Pulmonary trunk

These areas are significant for the outflow of blood from the heart.

Question 8

Where are venous reflections seen?

Answer 8

• SVC
• IVC
• Pulmonary veins

These reflections are important for the return of blood to the heart.

Question 9

What is a pericardial sinus?

Answer 9

Spaces between arterial and venous reflections

These sinuses play a role in the movement and positioning of the heart within the pericardial cavity.

Question 10

Which great vessels are in the pericardial sac?

Answer 10

SVC, IVC, ascending aorta, and pulmonary trunk

Question 11

What are the semilunar valves?

Answer 11

Aortic and pulmonary

Question 12

Does the right or left ventricle tend to be anterior?

Answer 12

Right

Question 13

What is the coronary sulcus?

Answer 13

Structure found between the atria and ventricles

Question 14

What is the interventricular sulcus?

Answer 14

Structure that separates ventricles

Question 15

Describe the first step in the development of sinuses.

Answer 15

The heart begins its development as a tube

Question 16

Describe the second step in the development of sinuses.

Answer 16

The heart begins to bend and loop as it forms

Question 17

What does the loop of the heart form during development?

Answer 17

A transverse pericardial sinus

Question 18

What structures can be found posterior to the pericardium in the posterior mediastinum?

Answer 18

Descending aorta, esophageal arteries, esophagus, L vagus nerve, and esophageal nerve plexus

Question 19

The right coronary artery branches into which arteries?

Answer 19

The right coronary artery that extends over the right chamber anteriorly and the posterior descending artery

Question 20

Fill in the blank: The area where the primordial arterial and venous ends are brought together forms the _______.

Answer 20

transverse pericardial sinus

Question 21

True or False: The left ventricle is typically positioned anteriorly.

Answer 21

False

Question 22

What is the role of the parietal pericardium?

Answer 22

It forms the outer layer of the pericardial cavity

Question 23

What is the significance of the primordial heart tube?

Answer 23

It is the initial structure from which the heart develops

Question 24

What happens to the veins during the development of the pericardium?

Answer 24

Veins expand and pericardial reflection is carried out around them to form oblique pericardial sinuses

Question 25

What is the function of small cardiac veins?

Answer 25

Small cardiac veins drain the right ventricle to the coronary sinus ## Footnote These veins play a crucial role in the venous drainage of the heart.

Question 26

The left coronary artery branches into which two arteries?

Answer 26

Circumflex artery and left anterior descending artery ## Footnote The left anterior descending artery is also known as the anterior interventricular artery.

Question 27

What is the role of the great cardiac vein?

Answer 27

The great cardiac vein drains the left ventricle ## Footnote This vein is important for the venous return from the heart's muscular walls.

Question 28

Where is the middle cardiac vein located and what does it drain into?

Answer 28

Found on the posterior side of the heart and drains into the coronary sinus ## Footnote It is essential for draining the blood from the heart's posterior regions.

Question 29

What structure does the coronary sulcus define?

Answer 29

Coronary sulcus separates the atria from the ventricles ## Footnote This groove is significant for the layout of the heart's anatomy.

Question 30

What are the main components of blood flow through the heart?

Answer 30

1. Blood returns to the heart into the right atrium via the vena cava (inferior or superior) 2. Blood passes through the tricuspid valve into the right ventricle 3. Blood pumps to the lungs out of the right ventricle through the pulmonary valve via the pulmonary artery 4. Oxygenated blood returns to the left atrium via pulmonary veins 5. Blood passes to the left ventricle through the mitral valve 6. Blood enters the aorta via the aortic valve and is pumped to the body ## Footnote This sequence outlines the systemic and pulmonary circulation processes.

Question 31

Fill in the blank: The _______ artery is also called the left anterior descending artery.

Answer 31

Anterior interventricular artery ## Footnote This artery is critical for supplying blood to the interventricular septum and parts of the ventricles.

Question 32

True or False: The right coronary artery supplies blood to the left ventricle.

Answer 32

False ## Footnote The left coronary artery primarily supplies the left ventricle.

Question 33

What does the right marginal artery supply?

Answer 33

Supplies the right ventricle ## Footnote It is an important artery for the right heart's blood supply.

Question 34

What is the function of the anterior cardiac veins?

Answer 34

Drain blood from the right ventricle directly into the right atrium ## Footnote These veins provide an alternative route for venous return from the right ventricle.

Question 35

What is the posterior interventricular artery also known as?

Answer 35

Posterior descending artery ## Footnote This artery is crucial for supplying the inferior part of the heart.

Question 36

What are the 3 layers of the heart wall?

Answer 36

Epicardium, myocardium, endocardium ## Footnote These layers each serve distinct functions and structures within the heart.

Question 37

What is the epicardium?

Answer 37

Visceral layer of serous pericardium ## Footnote It is the outermost layer of the heart wall.

Question 38

What is the myocardium?

Answer 38

Cardiac muscle ## Footnote This layer is responsible for the contraction of the heart.

Question 39

What is the endocardium?

Answer 39

Endothelium lining of the heart lumen; continuous with the vessels ## Footnote It provides a smooth lining for the heart chambers.

Question 40

Most ventricular septal defects come from...

Answer 40

The membranous part of the interventricular septum not closing properly ## Footnote This is a common congenital heart defect.

Question 41

What is the space just under the valves called?

Answer 41

The aortic vestibule ## Footnote It is the area leading into the aorta from the left ventricle.

Question 42

What is the function of the SA node?

Answer 42

It sends a signal through the atria and reaches the sulcus between the two sides, meeting the AV node ## Footnote The SA node is considered the pacemaker of the heart.

Question 43

What does the AV node do?

Answer 43

The signal from the AV node goes through the Purkinje fibers and AV bundle branches to each ventricle ## Footnote This is crucial for coordinating the contraction of the ventricles.

Question 44

Which artery provides blood supply to the SA and AV nodes?

Answer 44

Right coronary artery ## Footnote The right coronary artery is essential for the proper functioning of the heart's conduction system.

Question 45

Where is the apex of the heart located?

Answer 45

The 5th intercostal space, 3 inches left of the midsternal line ## Footnote This location is important for auscultation and clinical assessments.

Question 46

Where is the superior border of the heart found?

Answer 46

Left 2nd costal cartilage to right 3rd costal cartilage ## Footnote This border is significant for identifying the heart's position in the thoracic cavity.

Question 47

Where is the right border of the heart located?

Answer 47

From the end of the superior border to the 6th costal cartilage ## Footnote Understanding the heart's borders aids in imaging and surgical approaches.

Question 48

Where is the left border of the heart found?

Answer 48

From the end of the superior border to the apex ## Footnote The left border is crucial in determining the heart's silhouette on chest X-rays.

Question 49

Where is the inferior border of the heart located?

Answer 49

From the right 6th costal cartilage to the apex ## Footnote This border helps in assessing the heart's position relative to other thoracic structures.

Question 50

Where is the pulmonary valve located?

Answer 50

Connects right ventricle to pulmonary artery ## Footnote The pulmonary valve is essential for directing blood flow to the lungs.

Question 51

Where is the aortic valve found?

Answer 51

Connects left ventricle to aorta ## Footnote This valve is key for systemic blood circulation.

Question 52

Where is the mitral valve located?

Answer 52

Connects left atrium to left ventricle ## Footnote The mitral valve plays a critical role in preventing backflow during ventricular contraction.

Question 53

Where is the tricuspid valve located?

Answer 53

Connects the right atrium to the right ventricle ## Footnote The tricuspid valve is important for maintaining unidirectional blood flow within the heart.