trochlea

trochlea

The surgeon carefully examined the trochlea of the humerus.

Definition
  1. Noun (Anatomy):
    • Pulley-like structure: "trochlea" refers to a structure in the body that resembles a pulley, typically a groove or ridge around which a tendon or muscle passes to change the direction of its pull.
    • Specific anatomical examples: In human anatomy, the term is used for the trochlea of the humerus (the spool-shaped part of the upper arm bone that articulates with the ulna at the elbow) and the trochlea of the superior oblique muscle (a cartilaginous pulley in the orbit of the eye that guides the tendon of the superior oblique muscle).
Usage Examples
  • (The pulley-like part of the upper arm bone enables proper elbow movement.)
  • (The cartilaginous pulley in the eye socket facilitates specific eye motion.)
Advanced Usage

  • "trochlear nerve": The fourth cranial nerve (CN IV) that innervates the superior oblique muscle, which passes through the trochlea.

    • Damage to the trochlear nerve can cause vertical double vision because the superior oblique muscle cannot function properly. (Injury to the nerve controlling the eye's pulley system leads to visual disturbance.)

  • "trochlear notch": A depression in the ulna bone that articulates with the trochlea of the humerus.

    • The trochlear notch of the ulna fits around the humeral trochlea like a hinge. (The groove in the forearm bone matches the pulley-shaped part of the arm bone.)
Variants and Related Words

  • Trochlear (adj): relating to or resembling a trochlea; specifically, referring to the trochlea or the trochlear nerve.

    • The trochlear groove guides the tendon effectively. (The groove associated with the pulley-like structure directs the tendon.)

  • Trochleate (adj): having a trochlea or pulley-like shape.

    • The trochleate bone surface allows smooth tendon movement. (The bone surface shaped like a pulley facilitates frictionless motion.)
Synonyms
  • Pulley: a wheel with a grooved rim used to change the direction of a rope or cable; in anatomy, a direct synonym for "trochlea".
    • The anatomical pulley is essential for efficient muscle action. (The pulley-like structure is crucial for efficient motion.)
Related Idioms
  • (None applicable): "trochlea" is a technical anatomical term and does not appear in common idiomatic expressions.