Lumbar section how many vertebrae

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Adult Primary Care. Pediatric Primary Care. Urgent Care. The diameter ranges from 13 mm in the cervical and lumbar regions to 6. The cord is protected within the spinal canal and runs from the brainstem to the lumbar area where the cord fibres separate. The fibres then continue down through the canal to the sacrum and coccyx where they branch off to legs. The spinal nerves act as phone lines carrying messages back and forth between the body and spinal cord to control sensation and movement.

The spinal cord serves as an information highway, relaying messages between the brain and the body. Damage to the spinal cord may result in a loss of sensory and motor function below the level of injury. Back muscles stabilize the spine and support proper alignment of the vertebrae.

The three types of back muscles that help the spine function are extensors, flexors and obliques:. Facet joints make the spine flexible and enable us to bend and twist. Each vertebra has four facet joints, one pair that connects to the vertebra above and one below. Nerves branch out from the spinal cord through these joints to other body parts. Healthy facet joints have cartilage, which allows vertebrae to move smoothly against each other without grinding.

Each joint is lubricated with synovial fluid for additional protection against wear and tear. The system of ligaments in the spinal column combined with the tendons and muscles provides a natural brace to help protect the spine from injury while allowing flexion, extension, and rotation.

Ligaments of the spine are strong fibrous bands that hold the vertebrae together. Tendons are similar to ligaments in characteristics, except they connect the muscles to bones.

This sums up our mini anatomy lesson, we hope you enjoyed it. Looking to improve your back health? Feel free to consult a local chiropractor about your options. These vertebrae are much larger in size to absorb the stress of lifting and carrying heavy objects. Sacrum - the main function of the sacrum is to connect the spine to the hip bones iliac. There are five sacral vertebrae, which are fused together. Together with the iliac bones, they form a ring called the pelvic girdle.

Coccyx region - the four fused bones of the coccyx or tailbone provide attachment for ligaments and muscles of the pelvic floor. While vertebrae have unique regional features, every vertebra has three functional parts Fig.

Each vertebra in your spine is separated and cushioned by an intervertebral disc, which keeps the bones from rubbing together. Discs are designed like a radial car tire. The outer ring, called the annulus, has crisscrossing fibrous bands, much like a tire tread. These bands attach between the bodies of each vertebra. Inside the disc is a gel-filled center called the nucleus, much like a tire tube Fig. Discs function like coiled springs. The crisscrossing fibers of the annulus pull the vertebral bones together against the elastic resistance of the gel-filled nucleus.

The nucleus acts like a ball bearing when you move, allowing the vertebral bodies to roll over the incompressible gel. The gel-filled nucleus contains mostly fluid. This fluid is absorbed during the night as you lie down and is pushed out during the day as you move upright. With age, our discs increasingly lose the ability to reabsorb fluid and become brittle and flatter; this is why we get shorter as we grow older.

Also diseases, such as osteoarthritis and osteoporosis, cause bone spurs osteophytes to grow. Injury and strain can cause discs to bulge or herniate, a condition in which the nucleus is pushed out through the annulus to compress the nerve roots causing back pain. On the back of each vertebra are bony projections that form the vertebral arch. The arch is made of two supporting pedicles and two laminae Fig. The hollow spinal canal contains the spinal cord, fat, ligaments, and blood vessels.

Under each pedicle, a pair of spinal nerves exits the spinal cord and pass through the intervertebral foramen to branch out to your body. Surgeons often remove the lamina of the vertebral arch laminectomy to access the spinal cord and nerves to treat stenosis, tumors, or herniated discs. Seven processes arise from the vertebral arch: the spinous process, two transverse processes, two superior facets, and two inferior facets.

The facet joints of the spine allow back motion. Each vertebra has four facet joints, one pair that connects to the vertebra above superior facets and one pair that connects to the vertebra below inferior facets Fig.

The ligaments are strong fibrous bands that hold the vertebrae together, stabilize the spine, and protect the discs. Two transverse processes stick out of the sides of each vertebra. Muscles and ligaments that move and stabilize the vertebrae attach to the transverse processes. All of the above elements of the spinal column and vertebrae protect the spinal cord, which provides communication to the brain. The spinal cord also transmits sensation and mobility in the body through interaction of ligaments, bones and muscle structures of the back and its surrounding nerves.

The spinal cord ends at the L1 level, where it divides into many different nerve roots that travel to the lower body and legs. This bunch of nerve roots is called the cauda equina, which means "horse's tail. Neurosurgical Associates, P. Spinal Anatomy Overview The spinal column is one of the most important parts of the body, as it makes many different functions possible, including movement and balance. Sections The spine is composed of 33 bones, called vertebrae, divided into five sections: the cervical, thoracic, and lumbar spine sections, and the sacrum and coccyx bones.

Spinal Curvature Scoliosis The spine is normally a straight line when viewed from the back. The thoracic spine has a kyphotic curve, which means that it curves outward.

Parts of the Spine The spine is made of many parts that protect the spinal cord, facilitate movement and support the body. Nervous System All of the above elements of the spinal column and vertebrae protect the spinal cord, which provides communication to the brain. Clark, III, M.