Anatomy of the Thorax

Overview

• The thorax includes structures such as the ribcage, vertebrae, clavicle, scapula, and sternum.
• Anterior and posterior views of the thorax are important for understanding anatomy.

Thoracic Vertebrae

• 12 thoracic vertebrae (T1-T12) with lumbar vertebrae starting from T12.
• Ribs originate from thoracic vertebrae and attach to the sternum.

Ribcage

• Ribs:
  • True Ribs (1-7): Attach directly to the sternum.
  • False Ribs (8-10): Attach indirectly to sternum via cartilage.
  • Floating Ribs (11-12): Do not attach to sternum.
• Rib Types:
  • Typical: Ribs 3-9.
  • Atypical: Ribs 1, 2, 10-12.

The Sternum

• Composed of three parts: manubrium, body, and xiphoid process.
• Sternal Angle (Angle of Louis):
  • Important landmark where several structures intersect (e.g., T4-T5 junction, aortic arch).
  • Rib 2 articulates at this angle.

Thoracic Landmarks

• Midclavicular Line: From middle of clavicle downward.
• Midscapular Line: Middle of the scapula at the back.
• Midaxillary Line: Lateral aspect along the armpits.

Lung and Pleura

• Lung Margins:
  • Right Lung: Midclavicular at 6th rib, midaxillary at 8th rib, midscapular at 10th rib.
  • Left Lung: Midclavicular at 4th rib due to heart position.
• Pleura:
  • Parietal and visceral layers.
  • Pleura extends two ribs further than lung.

Disorders

• Pneumothorax (Collapsed Lung):
  • Can result from external trauma or internal conditions.
  • Air enters pleural cavity, compressing lung.
  • Seen in lung diseases (e.g., COPD) and certain body types (tall, skinny individuals).

Important Notes

• Anatomy of the thorax is crucial for understanding respiration and potential complications.
• Surface landmarks are vital for identifying positions in clinical practice.

This summary provides an understanding of the key anatomical features and potential issues related to the thorax, aiding in both education and clinical contexts.