They are sphincters. They are called internal and external (in relation to the bladder).
With the exception of the tongue (the heart is a special case), all muscles are attached at both ends
Muscles that connect at either or both ends of a bone and move parts of the skeleton.
Muscles that connect at either or both ends of a bone and move parts of the skeleton.
There is no defined region of urethra: it begins a at the bladder and ends at the head of the penis. The external urethra, the area that you can see, is called the meatus.
They warn Ralph that Jack plans to hunt him the next day and that Roger has "sharpened a stick at both ends."
crossing guard, security guard....
sentry
At both ends of your esophagus there is a ring of muscle. Usually, the muscles keep your stomach's contents where they belong. With laryngopharyngeal reflux, the muscles don't work right and stomach acids backs up into your throat.
These muscles are the pectoralis major and the pectoralis minor muscles.
The tongue muscle, primarily composed of intrinsic and extrinsic muscles, is not connected at both ends to allow for greater flexibility and mobility. This design enables the tongue to perform a wide range of movements necessary for essential functions such as speaking, swallowing, and tasting. Additionally, the lack of rigid connections at both ends allows for the adaptation of the tongue shape and position, facilitating its role in the oral cavity.
The tongue is a muscle that is not attached at both ends.
A line with an arrow at both ends is simply a line.