Retinaculum

from Wikipedia, the free encyclopedia

Retinaculum (plural retinacula ) is a term from anatomy and is used for retaining ligaments .

Mammalian Retinacula

In mammals, short, mostly ring-shaped holding ligaments of the tendons are called retinacula. Such straps around the tendons of extensor muscles are called retinaculum extensorum , those around flexor tendons are called retinaculum flexorum . The ligaments that hold the kneecap are called the retinacula patellae .

Retinacula of butterflies (Lepidoptera)

The retinaculum enables most butterflies in connection with the frenulum to couple the two pairs of wings together during flight so that they can be moved as one unit. It differs in position and design both within the various butterfly families and between the two sexes.

Retinaculum of the male

In the males it consists of a membranous hook, which in the primitive families is relatively short and broad at the base; in the remaining families it is long and narrow at the base. The frenulum hooks into this hook. In the dwarf leaf miners (Nepticulidae), the retinaculum consists of a series of strong, hook-like scales . In most species it arises at the base of the subcostal artery of the fore wing, between this and the costal artery or on a spur-like extension of the subcostal artery. In addition to this so-called subcostal retinaculum, the males of some species have a number of rigid bristles or hair-like subcubital scales. In some species of the moth (Pyralidae) these bristles also appear next to the subcostal retinaculum.

Retinaculum of the female

The hook-shaped subcostal retinaculum, which is typical of the males, occurs, mostly not fully developed, only in the females of the glass-winged (Sesiidae) and some species of the bearer moth (Lymantriidae).

The subcostal retinaculum of females otherwise consists of a series of hooks or bristles. In some species, however, the frenulum is only hooked through strong scaling at the base of the subcostal vein. In those females in which it is developed, the subcubital or subdorsal retinaculum plays a greater role in hooking the frenulum than in the males. In females, it consists of a group of modified scales.

Hymenoptera retinaculum

The retinaculum also couples forewings and hindwings in hymenoptera when flying and is located on the costa of the hindwings.

swell

  • Malcolm J. Scoble: The Lepidoptera: Form, Function and Diversity . Oxford University Press, Oxford 1995, ISBN 0-19-854952-0 (English).