Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2004 Feb;207(Pt 5):827-39.
doi: 10.1242/jeb.00819.

A three-dimensional kinematic analysis of tongue flicking in Python molurus

Affiliations
Comparative Study

A three-dimensional kinematic analysis of tongue flicking in Python molurus

Jurriaan H de Groot et al. J Exp Biol. 2004 Feb.

Abstract

The forked snake tongue is a muscular organ without hard skeletal support. A functional interpretation of the variable arrangement of the intrinsic muscles along the tongue requires a quantitative analysis of the motion performance during tongue protrusion and flicking. Therefore, high-speed fluoroscopy and high-speed stereo photogrammetry were used to analyse the three-dimensional shape changes of the tongue in Python molurus bivittatus (Boidae). The posterior protruding part of the tongue elongated up to 130% while the flicking anterior portion elongated maximally 60%. The differences in tongue strains relate to the absence or presence, respectively, of longitudinal muscle fibres in the peripheral tongue. Maximum overall protrusion velocity (4.3 m s(-1)) occurred initially when the tongue tip left the mouth. Maximum tongue length of approximately 0.01 body length (20 mm) was reached during the first tongue flick. These observations are discussed within the scope of the biomechanical constraints of hydrostatic tongue protrusion: a negative forward pressure gradient, longitudinal tongue compliance and axial tongue stiffness. The three-dimensional deformation varied along the tongue with a mean curvature of 0.06 mm(-1) and a maximum value of 0.5 mm(-1). At the basis of the anterior forked portion of the tongue tips, extreme curvatures up to 2.0 mm(-1) were observed. These quantitative results support previously proposed inferences about a hydrostatic elongation mechanism and may serve to evaluate future dynamic models of tongue flicking.

PubMed Disclaimer

Publication types

LinkOut - more resources