What is the embryological origin of the vertebrae?
During embryogenesis, the vertebral column derives from the somites, which are the primary segments of the embryonic paraxial mesoderm. Anatomical, cellular and molecular aspects of vertebral column development have been of interest to developmental biologists for more than 150 years.
How is the vertebral column formed?
The vertebral arch is formed by a pair of pedicles and a pair of laminae, and supports seven processes, four articular, two transverse, and one spinous, the latter also being known as the neural spine. Two transverse processes and one spinous process are posterior to (behind) the vertebral body.
What are the 7 process of vertebrae?
There are seven cervical vertebrae (but eight cervical spinal nerves), designated C1 through C7. These bones are, in general, small and delicate. Their spinous processes are short (with the exception of C2 and C7, which have palpable spinous processes). C1 is also called the atlas, and C2 is also called the axis.
How does the future spinal cord form in developing human embryos?
In an embryo, the spinal cord fills the canal, but as a result of normal growth and development, it will eventually change positions [12]. O’Rahilly states that development in the caudal areas of the nervous system promotes spinal cord ascension from the sacrum into the lumbar region, typically around level three [1].
What induces formation of vertebral bodies?
By about 28 days, the notochord fully demarcates the midline of the embryo1 and induces the formation of the vertebral column around it. Dorsal to the notochord, the ectoderm forms the neural tube, which differentiates into the brain and spinal cord.
How do vertebrae develop its spinous process?
The spinous process of a typical cervical vertebra is short and bifid posteriorly. It is bifid because it develops from two separate secondary centers of ossification. This morphology is unique to cervical spinous processes.
What is a vertebral process?
Spine Anatomy Overview Video. Spinous process is a bony projection off the posterior (back) of each vertebra. The spinous process protrudes where the laminae of the vertebral arch join and provides the point of attachment for muscles and ligaments of the spine.
Which embryonic structure is a precursor to the spinal cord?
The neural tube
Which embryonic structure is a precursor to the spinal cord? Explanation: The neural tube is a structure derived from the ectoderm that is found in chordates. The neural tube is formed by the closing of the neural folds, and runs along the dorsal-ventral axis of the developing embryo.
What kind of ossification is the vertebrae?
All vertebrae begin ossification in the embryonic period of development around 8 weeks of gestation. They ossify from three primary ossification centers: one in the endochondral centrum (which will develop into the vertebral body) and one in each neural process (which will develop into the pedicles).
What are the embryological stages of the central nervous system?
The CNS system involves 3 germinal layers: ectoderm, mesoderm, and endoderm. The ectoderm is the key initiating player in the embryogenesis of the CNS. The ectoderm is further sub-specialized as the (1) surface ectoderm, which differentiates into the epidermis, nails, and hair.
How many total primary ossification centers are found in the vertebrae?
With the exception of coccygeal vertebrae, there are three ossification centers per a vertebra: one in its body and one in either neural arch [1–3, 12, 21]. The first vertebral body ossification centers occur in the arches of upper cervical vertebrae, as early as at week 8 in the axis, and then progress caudad [6].