🦠 Anatomy: Inner Body Tube

The inner body tube houses the feeding and digestive machinery that enables plant parasitism. This lesson focuses on stomodeum, oesophagus, intestine, posterior gut, and associated glands.

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Digestive System Overview

The digestive tract is typically divided into stomodeum (foregut), mesenteron (intestine), and protodeum (hindgut). In plant-parasitic species, the foregut is highly specialized for host penetration and feeding.

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Stomodeum and Stylet Region

The stomatal opening leads into a cuticle-lined foregut. A stylet (where present) is the central feeding organ used for piercing plant cells and delivering secretions.

Foregut and stylet architecture is a major taxonomic and functional character in plant nematodes.

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Oesophagus, Intestine, and Hindgut

The oesophagus (pharynx) varies across groups and is used for both classification and functional interpretation. The intestine is generally a simple tube specialized for nutrient absorption.

The protodeum includes rectal/anal regions that complete digestion and excretion of gut residues.

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Associated Glands

Digestive and oesophageal gland secretions support host invasion, feeding-site establishment, and nutrient acquisition.

Because these secretions interact directly with host tissue, they are central to nematode pathogenicity.

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Summary Cheat Sheet

Topic	Key Point
Main gut divisions	Stomodeum, mesenteron, protodeum
Key parasitic adaptation	Stylet-mediated plant cell penetration
Oesophagus value	Functional + taxonomic significance
Intestine	Primary nutrient absorption tube
Glands	Secretions aid parasitism and feeding

Exam focus: digestive subdivisions and the diagnostic importance of stylet and oesophageal structures.

References

1 source • [1]

[1]

Inner body tube anatomy notes (PATH172)

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