MEDICAL DICTIONARY

Table of Contents

Abdominal viscera

Abdominal viscera refers to the internal organs located within the abdominal cavity, including organs involved in digestion, excretion, and other physiological functions. These organs are either classified as intraperitoneal, meaning they are suspended within the peritoneal cavity by mesentery, or retroperitoneal, meaning they are located behind the peritoneum.

Types of Abdominal Viscera

The abdominal viscera can be categorized based on their primary functions:

Digestive Organs

  • Stomach: A hollow organ responsible for mechanical and chemical digestion of food.
  • Small Intestine: Comprising the duodenum, jejunum, and ileum, it is the primary site of nutrient absorption.
  • Large Intestine: Includes the cecum, colon, rectum, and anal canal, and is involved in water absorption and stool formation.
  • Liver: The largest gland in the body, involved in metabolism, detoxification, and bile production.
  • Gallbladder: Stores and releases bile into the small intestine to aid fat digestion.
  • Pancreas: A dual-function gland that produces digestive enzymes (exocrine function) and insulin (endocrine function).

Excretory Organs

  • Kidneys: Bean-shaped organs responsible for filtering blood and producing urine.
  • Ureters: Tubes that transport urine from the kidneys to the bladder.

Lymphatic and Immune Structures

  • Spleen: Filters blood, recycles old red blood cells, and helps in immune response.
  • Lymph Nodes: Found along the mesentery and throughout the abdominal cavity, contributing to immune defense.

Supporting Structures

  • Peritoneum: A serous membrane lining the abdominal cavity and covering the abdominal organs, forming a protective layer and supporting organ mobility.
  • Mesentery: A fold of the peritoneum that suspends the intestines and provides pathways for blood vessels, nerves, and lymphatics.

Peritoneal vs. Retroperitoneal Viscera

  • Intraperitoneal Organs: Stomach, liver, spleen, most of the intestines.
  • Retroperitoneal Organs: Kidneys, pancreas (except the tail), parts of the duodenum, adrenal glands, aorta, and inferior vena cava.

Clinical Relevance

  • Peritonitis: Inflammation of the peritoneum, often due to infections or perforation of abdominal organs.
  • Visceral Pain: Pain arising from the abdominal viscera due to stretching, inflammation, or ischemia (e.g., appendicitis or bowel obstruction).
  • Organomegaly: Enlargement of abdominal viscera, such as hepatomegaly (liver enlargement) or splenomegaly (spleen enlargement).
  • Trauma or Injury: The abdominal viscera, particularly the spleen and liver, are prone to injury in cases of abdominal trauma.

Functions of the Abdominal Viscera

  • Digestion and Absorption: Breakdown of food and absorption of nutrients.
  • Detoxification and Metabolism: Carried out primarily by the liver.
  • Immune Defense: The spleen and lymphatic structures play key roles in immune response.
  • Fluid and Electrolyte Balance: Maintained by the kidneys and gastrointestinal tract.
References
  1. Gray, H. (1918). Gray’s Anatomy: The Anatomical Basis of Medicine and Surgery.
  2. Standring, S. (2020). Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 41st Edition.
  3. Moore, K. L., & Dalley, A. F. (2018). Clinically Oriented Anatomy.
  4. Wikipedia contributors. “Abdomen.” Wikipedia, The Free Encyclopedia.