Cranial Nerve Functional Components
Knowledge of the cranial nerve functional components provides the basis for a thorough neurological exam.
The 12 cranial nerves participate in a total of seven neural functions. Each of these seven functions is designated by a three letter acronym.
The first letter is either G (General) or S (Special).
General refers to primitive and/or external structures of the body.
Special refers to senses unique to the head (taste, olfaction, hearing, vision, and balance) and to muscles of branchial arch derivatives.
The second letter is either S (Somatic) or V (Visceral).
Somatic refers to non-visceral structures including skin, muscles, tendons, joints, retina (vision), basilar membrane (hearing), and utricle/saccula (balance).
Visceral refers to organs of the body cavity, smooth muscle, vessels, and glands.
The third letter is either A (Afferent) or E (Efferent).
Afferent refers to flow of neural information toward the brain (sensation)
Efferent refers to flow of neural information toward the periphery (motor).
The Seven Functional Components
GSA: General Somatic Afferent
Touch, temperature, and pain to non-visceral structures
GSE: General Somatic Efferent
Motor to skeletal muscle
GVA: General Visceral Afferent
Touch (distention), temperature, and pain from the viscera
GVE: General Visceral Efferent
Motor to viscera, smooth muscle, and glands
SSA: Special Somatic Afferent
Vision, hearing, and balance
SSE: Doesn't exist
None
SVA: Special Visceral Afferent
Taste and olfaction
SVE: Special Visceral Efferent
Motor to muscles derived from the branchial arches
This topic: Main
>
WebHome
>
HeadNeckLectures
>
FunctionalComponentsCranialNerves
>
CranialNerveFunctionalComponents
Topic revision:
30 Oct 2018,
LorenEvey
Copyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Structural Basis of Medical Practice?
Send feedback