Coccygeal Vertebrae

Definition

Coccygeal vertebrae are the small, fused bones that form the tailbone, located at the base of the vertebral column in humans. These vertebrae are a remnant of a tail found in other vertebrates and play a role in supporting pelvic organs and serving as an attachment site for various muscles and ligaments.

5 Must Know Facts For Your Next Test

1. The coccyx typically consists of three to five fused coccygeal vertebrae, resulting in a single triangular bone at the base of the spine.
2. Coccygeal vertebrae provide attachment for various ligaments and muscles involved in pelvic stability and support.
3. The coccyx can be susceptible to injury or pain, often referred to as coccydynia, which can occur from trauma or prolonged sitting.
4. Despite being vestigial, coccygeal vertebrae play a role in maintaining posture while sitting by providing balance and support to the pelvis.
5. Coccygeal vertebrae do not have intervertebral discs between them since they are fused; however, they still allow for some movement and flexibility.

Review Questions

• How do coccygeal vertebrae contribute to pelvic stability and support?
  • Coccygeal vertebrae serve as an important anchor point for ligaments and muscles that stabilize the pelvic region. By providing structural support at the base of the vertebral column, they help maintain proper posture while sitting and facilitate movements that involve the pelvic area. The attachment of these muscles contributes to overall pelvic function, including support for internal organs.
• Discuss the anatomical relationship between coccygeal vertebrae and other parts of the vertebral column.
  • Coccygeal vertebrae are located at the very bottom of the vertebral column, just below the sacrum, which consists of five fused vertebrae. Together, they form the terminal part of the spinal structure. The sacrum articulates with the ilium of the pelvis, while the coccyx serves as a support for pelvic organs and connects with muscles from both the sacrum and pelvis.
• Evaluate the significance of coccygeal vertebrae in human evolution and how their presence reflects changes in locomotion.
  • Coccygeal vertebrae highlight an evolutionary adaptation in humans as we transitioned from species with tails for balance during arboreal locomotion to bipedalism. The reduction to fused bones indicates a loss of function associated with tail use but retains anatomical remnants that support pelvic stability. This transition reflects changes in how our ancestors moved on land, requiring adaptations in skeletal structure to maintain balance and support during upright walking.

Related terms

Sacrum: The sacrum is a triangular bone formed by the fusion of five sacral vertebrae, situated between the lumbar vertebrae and the coccyx, contributing to the pelvis.

Vertebral Column: The vertebral column, or spine, is a bony structure composed of individual vertebrae that encases the spinal cord and provides structural support and flexibility to the body.

Pelvis: The pelvis is a basin-shaped structure that supports the spine and houses the pelvic organs, consisting of bones including the ilium, ischium, pubis, sacrum, and coccyx.