Thoracic and Abdominal Circulation Lecture Notes

Overview

• Focus on the thoracic aorta and its branches as it separates into the abdominal aorta.
• Diaphragm separates thoracic and abdominal aorta.
• Blank diagram available on Instagram as a template for reference during the lecture.

Thoracic Aorta

• Located superior to the diaphragm.
• Part of the descending aorta; branches include:
  • Posterior Intercostal Arteries: Supply blood between the ribs, serving external and internal intercostal muscles.
  • Superior Phrenic Artery: Supplies the diaphragm.
  • Bronchial Arteries: Supply the bronchi with oxygen-rich blood.
  • Esophageal Artery: Supplies the esophagus.
  • Mediastinal Artery: Supplies lymphatic structures in the mediastinum, including the thymus gland.
  • Pericardial Artery: Supplies the fibrous pericardium surrounding the heart.

Surrounding Structures

• Vertebral Column: Located posteriorly to the thoracic aorta.
• Left Pleura: Located to the left of the aorta.
• Right Thoracic Duct and Hemi-Azygos Vein: Located to the right of the aorta.

Abdominal Aorta

• Transitions from the thoracic aorta after passing through the diaphragm.
• Major branches of the abdominal aorta include:
  • Inferior Phrenic Artery: Supplies the inferior part of the diaphragm.
  • Renal Arteries: Right and left renal arteries supply the kidneys.
  • Adrenal Arteries (Supra Renal Arteries): Right and left, supply the adrenal glands.
  • Gonadal Arteries: Testicular (male) and ovarian (female) arteries supply respective reproductive organs.
  • Lumbar Arteries: Supply lumbar region muscles.

Branching of Common Iliac Arteries

• Common Iliac Arteries: Split into left and right common iliac arteries.
• Each common iliac artery branches into:
  • External Iliac Artery: Will be covered in another video.
  • Internal Iliac Artery: Branches include:
    • Superior Gluteal Artery: Supplies gluteus maximus, medius, and minimus.
    • Inferior Gluteal Artery: Supplies gluteus maximus, piriformis, and quadratus femoris.
    • Internal Pudendal Artery: Supplies external genitalia and perineum.
    • Obturator Artery: Supplies medial compartment of the thigh (adductor muscles).

Celiac Trunk

• Major artery that branches off the abdominal aorta, includes:
  • Left Gastric Artery: Supplies the stomach.
  • Splenic Artery: Supplies the spleen; branches into:
    • Left Gastroepiploic Artery: Supplies the greater omentum and stomach.
  • Common Hepatic Artery: Branches into:
    • Hepatic Artery Proper: Supplies the liver, branching into right and left hepatic arteries.
    • Right Gastric Artery: Supplies the pylorus and body of the stomach.
    • Gastro Duodenal Artery: Supplies pylorus of the stomach and duodenum, branches include:
      • Right Gastroepiploic Artery: Supplies lesser omentum.
      • Superior Pancreaticoduodenal Artery: Supplies the pancreas and duodenum.

Mesenteric Arteries

• Superior Mesenteric Artery: Supplies intestines, branches include:

  • Intestinal Arteries: Supply jejunum and ileum.
  • Ileocolic Artery: Supplies the cecum and appendix.
  • Right Colic Artery: Supplies the ascending colon.
  • Middle Colic Artery: Supplies the transverse colon.

• Inferior Mesenteric Artery: Supplies the lower intestines, branches include:

  • Left Colic Artery: Supplies descending colon.
  • Sigmoid Arteries: Supply sigmoid colon.
  • Superior Rectal Artery: Supplies the rectum, which branches into mid and inferior rectal arteries.

Marfan Syndrome

• An autosomal dominant disorder affecting connective tissue, caused by mutation in the fibrillin gene.
• Key effects include:
  • Decreased elasticity in vascular structures leading to risk of aortic dissection and ruptures.
  • Increased incidence of mitral valve prolapse.
  • Physical characteristics: tall stature, long fingers, hyperflexibility, and potential spinal deformities (scoliosis, pectus excavatum).
  • Increased risk of spontaneous pneumothorax.

Summary

• Understanding the blood supply of the thoracic and abdominal aorta is crucial for comprehending human anatomy and related pathologies, such as Marfan syndrome.
• Visual diagrams and structured outlines are recommended for effective learning.

Tips for Review

• Use diagrams to visualize the flow of blood from the thoracic aorta through to the abdominal aorta and its branches.
• Memorize key arteries and their functions for better retention.