External Anatomy Of The Spinal Cord

Explanation
The cervical enlargement refers to the region of the spinal cord that extends from the 4th cervical to the 1st thoracic vertebrae. This enlargement is responsible for supplying nerves to the upper limbs, allowing for the control and sensation of the arms and hands. It contains a greater number of neurons compared to other regions of the spinal cord, reflecting the increased neural input and output required for upper limb function.

Explanation
The correct answer is filum terminale. The filum terminale is an extension of the pia mater that attaches the spinal cord to the coccyx. It extends inferiorly from the conus medullaris, which is the tapered end of the spinal cord. The filum terminale helps to stabilize the spinal cord within the vertebral canal and prevents excessive movement. It is composed of fibrous tissue and is part of the coccygeal ligament. The cervical enlargement and lumbar enlargement are regions of the spinal cord where the nerves for the upper and lower limbs originate, respectively. The conus medullaris is the tapering end of the spinal cord, and the cauda equina is a bundle of nerves that extends from the conus medullaris.

Explanation
The conus medullaris is the correct answer because it is the tapered end of the spinal cord, which typically ends at the level of the intervertebral disc between the 1st and 2nd lumbar vertebrae. It is located below the lumbar enlargement and is the final portion of the spinal cord before it continues as the filum terminale and cauda equina.

Explanation
The lumbar enlargement refers to the section of the spinal cord that extends from the 9th to the 12th thoracic vertebrae. This region is characterized by a slight thickening of the spinal cord, which is responsible for supplying nerves to the lower limbs. The lumbar enlargement is an important anatomical feature as it contains the nerve roots that innervate the lower body, allowing for movement and sensation in the legs.

Explanation
The cauda equina is formed by the roots of the spinal nerves that emerge from the lower part of the spinal cord. These nerves travel inferiorly and fan out, resembling a horse's tail (cauda equina in Latin). The cauda equina is located below the conus medullaris, which is the tapered end of the spinal cord. The cervical enlargement and lumbar enlargement refer to the widened areas of the spinal cord in the neck and lower back, respectively. The filum terminal is a slender strand of connective tissue that extends from the conus medullaris to anchor the spinal cord.