Whisker Movement
In some mammals, some vibrissa follicles are motile. Typically, these are the large vibrissae (macrovibrissae) towards the rear of the mystacial area, whilst the supraorbital (above the eye) vibrissae and the much shorter vibrissae arrayed around the mouth or on the lips (microvibrissae) are immotile (see the whiskers held to the side, and out in front, in the two images of cats, below). A small muscle 'sling' is attached to each macrovibrissa and can move it more-or-less independently of the others, whilst larger muscles in the surrounding tissue move many or all of the whiskers together.
Amongst those species with motile whiskers, some (rats, mice, flying squirrels, gerbils, chincillas, hamsters, shrews, porcupines, opossums) move their vibrissae back and forth periodically, a movement known as whisking (Video of rat whisking), while other species (cats, dogs, racoons, pandas) do not appear to. The distribution of mechanoreceptor types in the whisker follicle differs between rats and cats, which may correspond to this difference in the way they are used. Whisking movements are amongst the fastest produced by mammals. In all whisking animals in which it has so far been measured, these whisking movements are precisely and rapidly controlled in response to behavioural and environmental conditions.
Read more about this topic: Whiskers
Famous quotes containing the words whisker and/or movement:
“The hapless Nymph with wonder saw:
A whisker first and then a claw,
With many an ardent wish,
She stretch’d in vain to reach the prize.
What female heart can gold despise?
What Cat’s averse to fish?”
—Thomas Gray (1716–1771)
“An actor rides in a bus or railroad train; he sees a movement and applies it to a new role. A woman in agony of spirit might turn her head just so; a man in deep humiliation probably would wring his hands in such a way. From straws like these, drawn from completely different sources, the fabric of a character may be built. The whole garment in which the actor hides himself is made of small externals of observation fitted to his conception of a role.”
—Eleanor Robson Belmont (1878–1979)