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Understanding the Anatomy of the Spleen

Sep 13, 2024

Lecture Notes: Anatomy of the Spleen

Introduction

  • Lecturer: Dr. Abhijit
  • Topic: Anatomy of the Spleen
  • Importance: Crucial for exams.

Topics Covered

  1. Nature and Function
  2. Surface Anatomy
  3. Size and Weight (Harry’s Dictum)
  4. Functions
  5. Shapes and Features
  6. Relations
  7. Hilum
  8. Parenchyma
  9. Clinical Correlations

Nature and Function

  • Lymphatic Organ: Connected to the vascular system.
  • In Fetal Life: Manufactures erythrocytes.
  • After Birth: Manufactures lymphocytes.

Surface Anatomy

  • Placement: Obliquely in the posterior part of the left hypochondrium.
  • Rib Location: Opposite the 9th, 10th, and 11th ribs.
  • Axis: Parallel to the 10th rib, making a 45-degree angle with the horizontal.
  • Palpability: Not palpable as it does not extend below the costal margin.

Size and Weight (Harry’s Dictum)

  • 1 inch: Thickness
  • 3 inches: Width
  • 5 inches: Length
  • 7 ounces: Weight (~200 grams)
  • Lies deep to ribs 9, 10, and 11.

Functions of the Spleen

  • Fetal Life: Manufacture of erythrocytes.
  • After Birth: Manufacture of lymphocytes.
  • Other Functions:
    • Removes worn-out erythrocytes.
    • Acts as a storage house for RBCs.

Shapes and Features

  • Ends: Medial (posterior extremity) and Lateral (anterior extremity).
  • Surfaces: Diaphragmatic (smooth) and Visceral (attached to organs).
  • Borders: Superior (convex with notches) and Inferior (rounded and smooth).

Relations

Diaphragmatic Surface

  • Separates spleen from:
    • Lower part of the left lung
    • Lower part of the left pleura
    • Posterior parts of the 9th, 10th, 11th ribs

Visceral Surface

  • Gastric Impression: Fundus of stomach
  • Renal Impression: Left kidney
  • Pancreatic Impression: Tail of pancreas
  • Colic Impression: Splenic flexure of colon

Hilum of the Spleen

  • Location: Longitudinal slit on the visceral surface.
  • Contents:
    • Terminal branches of splenic artery
    • Tributaries of splenic vein
    • Autonomic nerves and lymphatics

Peritoneal Ligaments

  • Gastrosplenic Ligament: Contains short gastric vessels and left gastroepiploic vessels.
  • Lienorenal Ligament: Contains splenic artery and tail of pancreas.

Splenic Parenchyma

  • Red Pulp: No lymphatics, collection of cells
  • White Pulp: Lymphatic nodules, known as Malpighian corpuscles

Clinical Correlations

  • Commonly Ruptured: Most common ruptured abdominal viscera.
  • Splenic Infarction: Causes referred pain to left shoulder (Kehr's sign).
  • Avascular Plane: Used for surgical incisions.

Blood Supply

  • Arterial: Via splenic artery (largest branch of the celiac trunk).
  • Venous: Drains into portal vein via splenic vein.

Nerve Supply

  • Sympathetic Vasomotor Fibers: From the celiac plexus.

Lymphatic Drainage

  • Few lymphatics arise from capsule and trabeculae, draining into pancreaticosplenic lymph nodes.

Conclusion

  • Next lecture will cover the anatomy of the pancreas.
  • PDF of the lecture notes will be made available for students.

Note: These notes cover the key points discussed during the lecture by Dr. Abhijit and are intended to be used as a study aid for understanding and revising the anatomy of the spleen.

Full transcript