Frenulum

:"Frenula redirects here. For the brachiopod genus, see "Frenula (brachiopod)A frenulum (or frenum, plural: frenula or frena, from the Latin "frēnulum", "little bridle", the diminutive of "frēnum" ) is a small fold of tissue that secures or restricts the motion of a mobile organ in the body. A short frenulum may require a frenectomy or frenuloplasty to achieve normal mobility.

Frenula on the human body include several in the mouth, some in the digestive tract, and some connected to the external genitalia:
* Oral tissue: Frenula of the mouth include the "frenulum linguae" under the tongue, the "f. labii superioris" inside the upper lip, the "f. labii inferioris" inside the lower lip, and the buccal frena which connect the cheeks to the gum. These can easily be torn by violent blows to the face or mouth, thus a torn frenulum is sometimes a warning sign of physical abuse.
* Vulvular tissue: In females, genital frenula include the "frenulum clitoridis" of the clitoris and the "frenulum labiorum pudendi" (aka "fourchette") where the labia minora meet at the back.
* Penile tissue: The word "frenulum" on its own is often used for the frenulum of prepuce of penis or "frenulum preputii penis", which is an elastic band of tissue under the glans penis that connects to the prepuce, or foreskin to the vernal mucosa, and helps contract the prepuce over the glans.
* Brain: Frenulum veli

In entomology

The word frenulum also refers to a bristle present at the root of the hindwing of most moths which engages with a small hook on the forewing to join the wings together.