Typical Vertebra
The vertebrae is composed of five different sections and 24 bones in total. When we are born we have 33 bones in the spine but 9 of those eventually fuse together. The spine is composed of five different sections.
1.) Cervical
2.) Thoracic
3.) Lumbar
4.) Sacrum
5.) Coccyx
- The Cervical area's main function is to support the weight of the head, around ten pounds. It also has the greatest range in motion. (C1-C7)
- The Thoracic area protects the organs in the chest by connecting to the rib cage. It also has a very limited range of movement. (T1-T12)
- The Lumbar's main function is to bear the weight of the body. They are also much larger than the other areas on the spine.(L1-L5)
- The Sacrum provides attachment of the lilac bones and protects the pelvic organs. The Sacrum is five different bones fused together.
- The Coccyx is made up of four bones that are fused together. It doesn't have an important function. A remnant of a tail from our primate ancestors
1.) Cervical
2.) Thoracic
3.) Lumbar
4.) Sacrum
5.) Coccyx
- The Cervical area's main function is to support the weight of the head, around ten pounds. It also has the greatest range in motion. (C1-C7)
- The Thoracic area protects the organs in the chest by connecting to the rib cage. It also has a very limited range of movement. (T1-T12)
- The Lumbar's main function is to bear the weight of the body. They are also much larger than the other areas on the spine.(L1-L5)
- The Sacrum provides attachment of the lilac bones and protects the pelvic organs. The Sacrum is five different bones fused together.
- The Coccyx is made up of four bones that are fused together. It doesn't have an important function. A remnant of a tail from our primate ancestors
Intervertebral Discs
-Invertebrate discs act as the spines shock absorbing system. They help protect the vertebrae, brain, and nerves from damage. The discs also allow flexation and extension movement.
- Each disc is composed of an annulus fibrosus and a nucleus pulposus. These discs help[ cushion the spine
- Each disc is composed of an annulus fibrosus and a nucleus pulposus. These discs help[ cushion the spine
Spinal Curvature
-Curves are in important thing to have in the spine.
-These curves make the spine six-teen times stronger than if the spine was perfectly straight.
-When the curve of the spine is lost the spinal cord and surrounding blood vessels are stretched.
- There are four natural curves in the body; thoracic, cervical, lumbar, sacral.
- Primary curvature in the Thoracic and Sacral is present at birth.
- Secondary curvature in the Cervical and Lumbar is present after birth.
-These curves make the spine six-teen times stronger than if the spine was perfectly straight.
-When the curve of the spine is lost the spinal cord and surrounding blood vessels are stretched.
- There are four natural curves in the body; thoracic, cervical, lumbar, sacral.
- Primary curvature in the Thoracic and Sacral is present at birth.
- Secondary curvature in the Cervical and Lumbar is present after birth.
Categories of joints
Fibrous
- Immoveable joints that are held together by a thin and strong layer of connective tissue. There are three different types of Fibrous joints; suture, gomphoses, and syndesmoses.
1.) Suture
- found only in the skull and are unique. Classified as immovable, they allow for skull growth. At birth, the cranial bones overlap to permit passage through the pelvis and the birth canal. After birth, the suture joints discourage excessive movement. The joint does not completely fuse until later in life when brain growth is complete.
2.) Gomphoses
- immovable joints found between the teeth and jaws. They are held together by a periodontal ligament that acts as a shock absorber.
3.) syndesmosis
- found at the intersection of the tibia and fibula. A tight ligament holds the two bones together to limit movement.
1.) Suture
- found only in the skull and are unique. Classified as immovable, they allow for skull growth. At birth, the cranial bones overlap to permit passage through the pelvis and the birth canal. After birth, the suture joints discourage excessive movement. The joint does not completely fuse until later in life when brain growth is complete.
2.) Gomphoses
- immovable joints found between the teeth and jaws. They are held together by a periodontal ligament that acts as a shock absorber.
3.) syndesmosis
- found at the intersection of the tibia and fibula. A tight ligament holds the two bones together to limit movement.
Cartilaginous
Cartilaginous joints are slightly moveable. There are two types of cartilaginous joints; symphyses and synchondros.
1.) Symphyses
- designed to allow for some give or motion. can be found in the vertebral column where one vertebra is attached to another by an invertebrate disk.
2.) Synchondros
- held close together by a strong, flexible shock absorbing cartilage. The joint between the first rib and the upper part of the breast bone, and joints of the body where two long bones are separated by a cartilaginous plate are a few examples.
1.) Symphyses
- designed to allow for some give or motion. can be found in the vertebral column where one vertebra is attached to another by an invertebrate disk.
2.) Synchondros
- held close together by a strong, flexible shock absorbing cartilage. The joint between the first rib and the upper part of the breast bone, and joints of the body where two long bones are separated by a cartilaginous plate are a few examples.
Synovial
considered movable joints and can be classified by three different categories.
1.) Uniaxial
- Joints that hinge (fingers) or pivot (rotation of the head).
2.) Biaxial
- Allow movement in saddle joints that allow rotation. The thumb is an example of a Biaxial Joint
3.) Triaxial
- Allows movement in ball and socket joints, like the hip.
1.) Uniaxial
- Joints that hinge (fingers) or pivot (rotation of the head).
2.) Biaxial
- Allow movement in saddle joints that allow rotation. The thumb is an example of a Biaxial Joint
3.) Triaxial
- Allows movement in ball and socket joints, like the hip.