Search results
Results From The WOW.Com Content Network
The giraffe's neck is elongated by heterochrony, extension of the time for the embryonic development of these bones. [4] By convention, the cervical vertebrae are numbered, with the first one (C1) closest to the skull and higher numbered vertebrae (C2–C7) proceeding away from the skull and down the spine. The general characteristics of the ...
They are located in the cervical region of the vertebral column from C3 to C7. [3] Two lips project upward from the superior surface of the vertebral body below, and one projects downward from the inferior surface of vertebral body above. They allow for flexion and extension and limit lateral flexion in the cervical spine.
Joint stability is easily evaluated by the use of flexion and extension lateral x-ray views of the spine. A summary of part of the DRE tables (6) give a guide as to the implications of the joint instability. If either translation or angular change is determined from flexion to extension to the degree shown in the table below, then Category IV ...
In about 10% of people, both the total number of pre-sacral vertebrae and the number of vertebrae in individual parts of the spine can vary. [ 14 ] [ 15 ] The most frequent deviations are eleven (rarely thirteen) thoracic vertebrae, four or six lumbar vertebrae and three or five coccygeal vertebrae (rarely up to seven).
The spinal nerves arise from the spinal column. The top section of the spine is the cervical section, which contains nerves that innervate muscles of the head, neck and thoracic cavity, as well as transmit sensory information to the CNS. The cervical spine section contains seven vertebrae, C-1 through C-7, and eight nerve pairs, C-1 through C-8.
When the shoulder is fixed, levator scapulae rotates to the same side and flexes the cervical spine laterally. When both shoulders are fixed, a simultaneous co-contraction of both levator scapulae muscles in equal amounts would not produce lateral flexion or rotation, and may produce straight flexion or extension of the cervical spine.
The number of vertebrae in a region can vary but overall the number remains the same. In a human spinal column, there are normally 33 vertebrae. [3] The upper 24 pre-sacral vertebrae are articulating and separated from each other by intervertebral discs, and the lower nine are fused in adults, five in the sacrum and four in the coccyx, or tailbone.
Principle I: When the spine is in neutral, sidebending to one side will be accompanied by horizontal rotation to the opposite side. [2] This law is observed in type I somatic dysfunction, where more than one vertebra is out of alignment and cannot be returned to neutral by flexion or extension of the vertebrae. The involved group of vertebrae ...