A girdle bone is a part of either the shoulder girdle or the pelvic girdle, two bony structures in vertebrates that support the limbs.
Understanding the Girdle Bones
The term "girdle bone" refers to the bones that form the girdles:
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Shoulder Girdle (Pectoral Girdle): This girdle supports the upper limbs (arms). It primarily consists of the clavicle (collarbone) and the scapula (shoulder blade) in humans. Other vertebrates may have variations in these bones or additional elements.
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Pelvic Girdle: This girdle supports the lower limbs (legs). It is composed of two hip bones, each formed by the fusion of the ilium, ischium, and pubis. These bones connect to the sacrum, forming a strong structure crucial for weight bearing and locomotion.
The reference states that girdle bones are "more or less complete bony rings at the anterior and posterior ends of the vertebrate trunk supporting the arms and legs respectively". This highlights their function as structural supports for the limbs, providing attachment points for muscles and allowing for movement.
Importance of Girdle Bones
Girdle bones play a vital role in:
- Locomotion: They provide a stable base for limb movement, facilitating activities like walking, running, and swimming.
- Weight Bearing: The pelvic girdle, in particular, is crucial for supporting the weight of the upper body.
- Muscle Attachment: Many important muscles attach to the girdle bones, enabling a wide range of movements.
