CV1 Soft Tissue Checklist Review Video Notes

Introduction

• The practical exam focuses on soft tissue structures of the chest.

• Emphasis on laterality when identifying structures, especially if asymmetric.

  • Example: Left vagus nerve vs. Right vagus nerve – they take different courses in the body.

• Different anatomical views will be presented: oblique, lateral, and anatomical.

Anterior Chest Anatomy

• Internal Intercostal Muscle

  • Fiber direction: superior and medial.

• External Intercostal Muscle

  • Fiber direction: inferior and medial.

• Mnemonics: "in to chin" = internal intercostal, "x to sext" = external intercostal.

Anatomical Positioning

• Donor is flipped, with superior positioned at the bottom for clearer anatomical view.
  -Innermost Intercostal Muscle

• Transversus Thoracis

  • Located inside the chest wall, extends laterally from sternum.

• Intercostal Nerve

  • Visible on the inferior aspect of each rib.

• Zoomed view reveals:

  • Internal Thoracic Artery: moves inferiorly along the lateral edge of the sternum.

  • Anterior Intercostal Artery, Intercostal Vein, Intercostal Nerve: all run as a bundle beneath each rib.

  • Internal Thoracic Artery splits:

  • Medially: Superior Epigastric Artery

  • Laterally: Musculophrenic Artery.

Internal Thoracic Cavity

• Pericardium Configuration:

  • Fibrous Pericardium: outer layer protecting the heart.

  • Parietal Layer of Serous Pericardium: inner layer that contacts the heart.

  • Visceral Layer: directly on the heart muscle.

• Cardiovascular System Blood Flow:

  • Blood flows from Left Ventricle to Aorta:

  • Aortic Arch branches into:

    1. Brachiocephalic Trunk

    2. Left Common Carotid Artery

    3. Left Subclavian Artery.

• Superior Vena Cava: returns blood to the right atrium from various veins (right/left brachiocephalic veins, internal jugular veins, and subclavian veins).

Cardiac Anatomy with Eviscerated Lungs

• Clinical relevance of Heart Sinuses:

  1. Oblique Pericardial Sinus: extends from apex to base of heart.

  2. Transverse Pericardial Sinus: located posterior to great vessels; can be clamped in surgery.

• Pericardiacophrenic Artery and Phrenic Nerve: run laterally to the heart, towards diaphragm.

• Cardiac Structures:

  • Pulmonary Trunk from right ventricle.

  • Ascending Aorta and Aortic Arch from left ventricle.

  • Ligamentum Arteriosum: remnant of the ductus arteriosus, crucial in fetal development for by-passing lungs.

Vagus Nerve Anatomy

• Left Vagus Nerve: runs anterior to the aortic arch and gives off:

  • Left Recurrent Laryngeal Nerve: loops under the aortic arch.

• Right Vagus Nerve: positioned posteriorly to esophagus (mnemonic: LARP = Left Anterior, Right Posterior).

Posterior Thoracic Structures

• Parietal Pleura Components:

  • Costal Parietal Pleura: attaches to the thoracic wall.

  • Diaphragmatic Parietal Pleura: attaches to diaphragm dome.

  • Mediastinal Parietal Pleura: covers mediastinum.

• Diaphragmatic Features: Structures passing through at various vertebral levels:

  • Inferior Vena Cava: T8

  • Esophagus: T10

  • Aorta: T12.

  • Mnemonic: "I ate 10 eggs at noon".

Posterior Thoracic Wall Viewed Laterally

• Sympathetic Chain: running along vertebral bodies; branches include greater splanchnic nerve.

• Neurovasculature:

  • Intercostal Nerve, Posterior Intercostal Artery, Intercostal Vein (VAN order).

• Arch of Azygos Vein: drains into superior vena cava, receives blood from:

  • Right Superior Intercostal Vein,

  • Hemiazygos and Accessory Hemiazygos veins drain into the azygos system.

Azygos System and Thoracic Duct

• The Thoracic Duct: located between esophagus and azygos vein.

• Hemiazygos Vein: drains inferior wall;

• Accessory Hemiazygos Vein: drains superior wall of thorax.

Lung Anatomy

• Left Lung:

  • Two lobes: Superior lobe and Inferior lobe.

  • Oblique Fissure separating lobes.

  • Lingula: projection from superior lobe, adjacent to heart (mnemonic: "lingula licks the heart").

  • Cardiac Notch: indentation in left lung.

• Right Lung:

  • Three lobes: Superior, Middle, and Inferior lobes.

  • Two fissures: oblique and horizontal.

• Hilum Structures:

  • Contains bronchus, pulmonary artery, pulmonary veins with orientation mnemonics:

  • RALS: Right Anterior Left Superior for positioning of pulmonary artery relative to bronchus.

Heart Orientation and Internal Anatomy

• Anatomical Position of the Heart:

  • Right Atrium: posterior to right auricle.

  • Left Atrium: posterior aspect of heart.

  • Right Ventricle: anterior chamber, pumps to lungs via pulmonary semilunar valve.

  • Left Ventricle: largest chamber, pumps to systemic circulation via aortic valve.

• Coronary Circulation:

  • Right Coronary Artery branches into:

  • SA Nodal Artery: supplies SA node.

  • Right Marginal Artery: perfuses right ventricle.

  • Posterior Interventricular Artery: wraps the heart.

  • Left Coronary Artery: divides into Left Circumflex and Left Anterior Descending arteries.

• Veins draining into either coronary sinus or directly into right atrium (e.g., small cardiac veins).

Internal Structures of the Heart

• Right Ventricle:

  • Inner wall: Trabeculae Carne (rough texture).

  • Papillary Muscles: (3 types):

  1. Anterior

  2. Posterior

  3. Septal (attached to interventricular septum).

  • Moderator Band: assists conduction in right ventricle.

  • Chorade Tendinae: links papillary muscles to valves.

• Pulmonary Semilunar Valve: made up of three cusps.

Left Ventricle Structures

• Thicker walls than the right ventricle.

• Two papillary muscles associated with Mitral Valve: anterior and posterior.

• Orientation of major vessels:

  • Superior Vena Cava: most posterior,

  • Ascending Aorta: central,

  • Pulmonary Trunk: most anterior.

Blood Flow Overview

1. Deoxygenated Blood:

   • Returns via SVC and IVC to right atrium.

   • Flows through tricuspid valve into right ventricle.

   • Pulmonary semilunar valve directs it to thelungs.

2. Oxygenated Blood:

   • Returns via pulmonary veins into left atrium.

   • Flows through mitral valve into left ventricle.

   • Aortic semilunar valve sends blood into aorta for systemic circulation.

3. Coronary Ostia: located above aortic semilunar valve, perfuses heart during diastole.

Conclusion

• Aim of the video is to assist with practical examinations and identification of structures.

• Students are encouraged to consult tutors and faculty for clarifications beyond video content.

• Good luck in studying!