What is "retinaculum"

Retinaculum \Ret`i*nac"u*lum\, n.; pl. Retinacula. [L., a holdfast, a band. See Retain.]

1. (Anat.)

   1. A connecting band; a fr[ae]num; as, the retinacula of the ileoc[ae]cal and ileocolic valves.

   2. One of the annular ligaments which hold the tendons close to the bones at the larger joints, as at the wrist and ankle.

2. (Zo["o]l) One of the retractor muscles of the proboscis of certain worms.

3. (Bot.) A small gland or process to which bodies are attached; as, the glandular retinacula to which the pollinia of orchids are attached, or the hooks which support the seeds in many acanthaceous plants.

n. 1 (context anatomy English) A connecting band. 2 (context anatomy English) One of the annular ligaments which hold the tendons close to the bones at the larger joints, as at the wrist and ankle. 3 (context zoology English) One of the retractor muscles of the proboscis of certain worms. 4 (context zoology English) A loop on the underside of the forewing of some moths. 5 (context botany English) A small gland or process to which bodies are attached; as, the glandular retinacula to which the pollinia of orchids are attached, or the hooks which support the seeds in many acanthaceous plants.

A retinaculum (plural retinacula) is a band around tendons that holds them in place. It is not part of any muscle. Its function is mostly to stabilize a tendon. The term retinaculum is New Latin, derived from the Latin verb retinere (to retain). Specific retinaculum include:

• In the wrist:
  • Flexor retinaculum of the hand
  • Extensor retinaculum of the hand
• In the ankle:
  • Flexor retinaculum of foot
  • Peroneal retinacula
  • Superior extensor retinaculum of foot
  • Inferior extensor retinaculum of foot
  • Superior fibular retinaculum
  • Inferior fibular retinaculum
• In the knee:
  • Lateral retinaculum
  • Medial patellar retinaculum

Retinaculum may refer to:

In vertebrate anatomy:
Retinaculum,a band around tendons that holds them in place.

• Extensor retinaculum of the hand
• Flexor retinaculum of the hand
• Flexor retinaculum of foot
• Inferior extensor retinaculum of foot
• Lateral retinaculum
• Medial patellar retinaculum
• Peroneal retinacula
• Retinaculum cutis mammae, Latin name for connective breast tissue
• Superior extensor retinaculum of foot

In invertebrate anatomy:

• the retinaculum, in wing
• the Retinaculum (springtail), in springtail abdomen
• Buffetia retinaculum, a species of air-breathing land snail