Anatomy LC7: Cardiac Nerve and Blood Supply

Questions and Answers

What is the anatomical starting point of the thoracic duct?

Superior hemiazygos vein

Left crus of the diaphragm

Azygos vein

Cisterna chyli (correct)

Which vessel does the thoracic duct primarily join?

Superior hemiazygos vein

Inferior vena cava

Azygos vein (correct)

Left subclavian vein

At which anatomical level does the thoracic duct bend laterally behind the carotid sheath?

T8 level

T6 level

T10 level

T4 level (correct)

From where does the superior hemiazygos vein receive its tributaries?

Left superior intercostal vein and fourth to eighth intercostal veins Signup and view all the answers

What area does the thoracic duct primarily drain?

Left side and lower half of the body Signup and view all the answers

What is the primary source of parasympathetic nerve supply to the heart?

Vagus nerves Signup and view all the answers

Which nodes receive postganglionic parasympathetic fibers?

Sinoatrial and atrioventricular nodes Signup and view all the answers

Which statement regarding the sympathetic nerve supply to the heart is accurate?

It is responsible for positive chronotropic effects. Signup and view all the answers

What characterizes coronary artery dominance?

Supremacy of the posterior descending artery from the right coronary artery Signup and view all the answers

What effect does parasympathetic stimulation have on heart rate?

Decreases heart rate Signup and view all the answers

Which of the following correctly describes intrinsic nerve supply?

Local nerve networks within the heart Signup and view all the answers

What is the primary role of the conducting system of the heart?

To coordinate heart muscle contractions Signup and view all the answers

What distinguishes the intrinsic cardiac conduction pathway?

It operates independently from autonomic nerve influences. Signup and view all the answers

What causes the formation of new blood vessels in the heart after an MI?

Ischemia due to decreased blood flow Signup and view all the answers

Which coronary artery primarily supplies the Atrioventricular node?

Right coronary artery Signup and view all the answers

What role do new blood vessels play in the cardiac supply after ischemia?

They provide supply but are initially not very functional Signup and view all the answers

If the left atrium is blocked, what would potentially occur?

Formation of collateral blood vessels Signup and view all the answers

Which branch primarily supplies the heart's anterior region?

Left anterior descending artery Signup and view all the answers

What happens to new blood vessels over time in the heart?

They grow in size and become functional Signup and view all the answers

Which structure is supplied by multiple coronary arteries?

Left bundle branch Signup and view all the answers

What is the primary role of the right coronary artery in the heart?

It is mainly responsible for the supply to the Atrioventricular node and bundle Signup and view all the answers

What is the main pathway for the Azygos vein to ascend in the body?

Through the aortic opening in the diaphragm Signup and view all the answers

Which segment of the spine aligns with the Azygos vein's drainage into the superior vena cava?

5th thoracic vertebra Signup and view all the answers

What structures does the Azygos vein specifically drain?

The diaphragm and pericardium Signup and view all the answers

Which veins contribute to the formation of the Inferior Hemiazygos vein?

Left ascending lumbar and left subcostal veins Signup and view all the answers

What is the positioning of the Azygos vein relative to the aorta as it ascends?

To the right side of the aorta Signup and view all the answers

Which nodes drain into the bronchomediastinal trunk?

Posterior intercostal nodes Signup and view all the answers

What is an alternate route for lymph to enter the thoracic duct from the anterior parts of the intercostal space?

By the internal thoracic nodes Signup and view all the answers

Which vein specifically drains the posterior parts of the intercostal spaces?

Azygos vein Signup and view all the answers

Which structure is primarily supplied by the right coronary artery?

Sinoatrial node Signup and view all the answers

What is the first branch of the aortic arch?

Brachiocephalic artery Signup and view all the answers

Which of the following does NOT receive innervation from the extrinsic nerve supply's post-ganglionic sympathetic fibers?

Pulmonary veins Signup and view all the answers

Which component is NOT typically supplied by the right coronary artery?

Left atrial wall Signup and view all the answers

Which vessel is directly associated with the first branch of the aortic arch?

Brachiocephalic trunk Signup and view all the answers

Which one of these structures is supplied by the right coronary artery?

Atrioventricular bundle Signup and view all the answers

Which of the following statements is false regarding the right coronary artery?

It supplies the aortic arch. Signup and view all the answers

Which of the following structures is least likely to be influenced by the post-ganglionic sympathetic fibers?

Pulmonary arteries Signup and view all the answers

Study Notes

Cardiac Nerve Supply

Extrinsic Nerve Supply: Includes nerves that originate outside the heart and influence heart function.
Intrinsic Nerve Supply: Comprises specialized cardiac muscle fibers that generate electrical impulses.
Conducting System: Includes the sinoatrial (SA) node, atrioventricular (AV) node, and bundles for impulse conduction.
Internodal Conduction Pathway: Transmits impulses between the SA node and AV node.

Parasympathetic Nerve Supply

Arises from the Vagus Nerves, with branches entering the thorax.
Postganglionic fibers terminate on the SA and AV nodes, impacting heart function without affecting cardiac muscle directly.
Results in negative chronotropic effects, leading to a decreased heart rate.

Arterial Supply of the Heart

Right Coronary Artery: Supplies right atrium, portions of the right ventricle, and nodes.
Left Coronary Artery: Divides into the anterior descending and circumflex arteries, supplying the left ventricle and more.
Coronary Artery Dominance: Determines which coronary artery supplies the heart muscle, influencing clinical outcomes.

Venous Drainage of the Heart

Main Azygos Vein: Drains posterior intercostal spaces, the posterior abdominal wall, diaphragm, and more.
Inferior Hemiazygos Vein: Formed by left ascending lumbar and left subcostal veins, draining lower posterior intercostal spaces.
Lymphatic Drainage: Deep lymph vessels from anterior intercostal spaces drain into thoracic duct via internal thoracic nodes and bronchomediastinal trunk.

Surface Anatomy of the Heart

Large Arteries of the Thorax: Key arteries visible in the anterior view are crucial for understanding cardiac placement.
Bronchomediastinal Trunk: Collects lymph from thoracic structures and drains into the thoracic duct.
Atrioventricular Node: Primarily supplied by the right coronary artery.

Important Notes on Ischemia and Collateral Circulation

Myocardial infarction (MI) leads to ischemia, prompting the heart to regenerate new blood vessels.
Persistent increased oxygen levels in the heart stimulate the formation of new vascular connections to maintain perfusion.
New vessels can initially function at a reduced capacity but develop over time, enhancing coronary supply.

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Description

This quiz covers the cardiac nerve supply, arterial supply, venous drainage, and surface anatomy related to the heart. It is designed for medical students in the University of Northern Philippines' College of Medicine, Batch 2026. Test your understanding of these essential anatomical concepts.