Flashcards in Lumbar Spine Anatomy Deck (30):
The human spine
The human spine is made of 24 vertebra. The vertebra stack on top of one another to create the spinal column. The spinal column gives the body its main upright support. From the side the spine forms 3 curves. The neck, called the cervical spine curves lightly inward. The mid-back or thoracic spine curves outward.
The inward curve of the lower back
What makes up the lower lumbar spine?
The lower 5 vertebra often referred to as l1 - l5
What does the L5 connect to?
The L5 connects to the Sacrum, the triangular bone at the base of the spine that fits between the two pelvic bones.
Sacroiliac Joints (SI Joints)
The joints that connect the Sacrum to the Pelvis
Each vertebra is formed by a round block of bone called the vertebral body
How do lumbar vertebral bodies compare to the vertebral bodies of other parts of the spine?
The lumbar vertebral bodies are taller and bulkier partly because because the lumbar spine has to sustain pressure from the body weight and from daily actions like lifting and carrying and twisting
What connects to the back of the vertebral body?
A bony ring. When the vertebra are stacked they create a hollow tube called the spinal canal. This boney tube surrounds the spinal cord as it passes through the spine.
What do the spinal column protect?
Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.
How far does the spinal cord extend?
From the brain to the L2 vertebra
What happens to the spinal cord below the L2 vertebra?
The spinal cord splits into a bundle of nerves that goes to the lower limbs and pelvic organs
The latin term for the bundle of nerves below the L2 vertebra meaning horse's tail
What does the spinal cord do as it travels from the brain to the base of the spine?
It sends out nerves on the side of each vertebra called nerve roots
What do the nerve roots do
They join with the rest of the nerves to create the body's electrical system.
What makes up a spinal segment
Two vertebra, intervertebral disc between, two nerve roots that leave the spinal cord at that level and two facet joints that link each level of the spinal column
What makes up the intervertebral disc?
The intervertebral disc is made up of two parts: the center is called the nucleus pulposus is spongy and acts as a shock absorber to cushion the force between each vertebra. The nucleus is surrounded by a series of strong ligimentous rings called Annulus Fibrosus
What are ligaments made of?
Strong connective tissue that connects one bone to another
What is the Annulus Fibrosus
A special ligament that connects two vertebra together
Between the vertebra in each spinal segment are two facet joints. They are located on the back of the spinal column.
How do facet joints connect vertebral bodies?
A small boney knob that sticks out from the vertebral body at the back of the spine. Where these knobs meet create a synovial joint that connects the two vertebra.
most moveable and widespread joint throughout the body
How do the facet joints move in the lumbar spine?
The facet joints move together in a sliding motion as you bend forward and backward
The surfaces of the facet joints are covered by articular cartilage. It's a smooth rubbery material that covers the ends of most joints. It allows the bone ends to move together smoothly without friction
As the nerves leave the spinal cord they pass through a small boney tunnel called a neural foramen
The lumbar spine is supported by a complex set of ligaments and muscles. The ligaments are arranged in layers and run in multiple directions where they connect the bones of the spine to the sacrum and pelvis.
The muscles of the lower back are also arranged in layers.
Superficial (top) muscle layer
Those closest to the surface are covered by a thick tissue called fascia (fasha)
Middle muscle layer
Runs up and down over the middle layer, chest and lower back. They blend in the lumbar spine to form a thick tendon that binds the bones of the lower back, sacrum and pelvis
Deep muscle layer
Runs along the back surface of the spine. These muscles connect the lumbar vertebra to the sacrum and pelvis. They coordinate movement with the muscles of the abdomen to hold the spine steady during activities