Integument

Definition

The outer covering of an organism's body, consisting of the cuticle and the underlying epidermal cell layer. In arthropods, the integument forms the structural basis of the exoskeleton and serves as the primary interface between the organism and its environment, providing protection, waterproofing, structural support, and sites for sensory structures. The integument is periodically shed during ecdysis to allow for growth.

Etymology

From Latin integumentum, meaning 'covering' or 'enclosure'.

Example

The integument of a cicada nymph, comprising the layered cuticle and epidermis, is cast off as a complete exuvia during the final molt to the adult stage.

Related Terms

• Cuticle
• Epidermis
• Exoskeleton
• Ecdysis
• exuvia
• Chitin
• epicuticle

Usage Notes

In entomology, 'integument' specifically denotes the cuticle plus epidermis, whereas 'exoskeleton' and 'cuticle' are often used more loosely for the hardened outer structure alone. The term applies broadly across invertebrates and vertebrates, but arthropod integuments are distinguished by their chitinous composition and molting cycle.