- The annulus fibrosus is the tough circular exterior of the intervertebral disc that surrounds the soft inner core, the nucleus pulposus.
- This outer portion is composed of a ring of ligament fibers that encases the inner core of the disc and securely connects the spinal vertebrae above and below the disc.
- A hernia occurs when an organ pushes through an opening in the muscle or tissue that holds it in place. Hernias are most common in the abdomen, but they can also appear in the upper thigh, belly button, and groin areas.
Common hernia types
- Inguinal hernia
- Hiatal hernia
- Umbilical hernia
- Incisional hernia.
PARTS OF INTERVERTEBRAL DISC:
- The filum terminale is a structure usually less than 2 mm in diameter. The filum terminale is the point at which the spinal cord terminates. It is a slender thread of pia mater that provides support to the spinal column. Its upper part is called the filum terminale internum and its lower part is called the filum terminale externum.
- The sacrum is a large bone located at the terminal part of the vertebral canal, where it forms the posterior aspect of the pelvis. It is remarkably thick, which aids in supporting and transmitting the weight of the body.
- The sacrum is formed by the fusion of the five sacral vertebrae. It has an inverted triangular, concave shape. The bone consists of a base, apex and four surfaces- anterior surface, posterior surface, pelvic surface and dorsal surface.
- There are two classifications of ribs – atypical and typical. The typical ribs have a generalised structure, while the atypical ribs have variations on this structure.
- Ribs 11 and 12 do not have an anterior attachment and end in the abdominal musculature. Because of this, they are called ‘floating ribs’